LARENCE ^l. icr ^ ' "^ 7 /> BUTTERFLIES WORTH KNOWING Fnnn a dnniiiKj by S. Shimotori THE REGAL FRITILLARY, FEMALE See page IM) LITTLE NATURE LIBRARY BUTTERFLIES WORTH KNOWING By clarence M. WEED, D. Sc. AUTHOR OF Seeing Nature First, Nature Biographies, Ten New England Blossoms, The Flower Beautiful, etc. Illustrated by Forty-eight Plnf^ - ,_ Thirty-two in Colo^o^^^WSONlA.fj' JUN2 71987 UBRARvt.^ Garden City New York DOUBLEDAY, PAGE & COMPANY 1917 Copyright, 1917, by DOUBLEDAY, PaGE & CoMPANT All rights reserved, including thai of translation into foreign languages, including the Scandinavian PREFACE In this little book an attempt has been made to discuss the more abundant and widely distributed butterflies of eastern North America from the point of view of their life histories and their relations to their surroundings. In so doing I have of course availed myself of the written records of a host of students of butterflies, without whose labors no such volume would be possible. Among these two names stand out preeminent — William H. Edwards and Samuel H. Scudder. Each was the author of a sumptuous work on American butterflies to which all later students must refer, both for information and for inspira- tion. Many others, however, have made notable contri- butions to our literature of these ethereal creatures . Every seeker after a knowledge of butterflies will soon find himself indebted to the writings of such investigators as the Comstocks, Denton, Dickerson, Dyar, Fernald, Fiske, Fletcher, French, Hancock, Holland, Howard, Longstaff, Newcomb, Riley, Skinner, Wright, and many others. I am glad to express my obligations to all of these for the assistance their records have given in the prepara- tion of this book. While a vast amount of knowledge of butterflies has already been discovered there is still more to be learned concerning them, and throughout these pages I have attempted to indicate the more important opportunities awaiting investigation. The day of the field naturalist has vi PREFACE come again and the butterflies are well worthy of careful observations by many interested students. The illustrations in the book require a word of credit. The eleven color plates of adult butterflies with wings spread have been made direct from a set of the remarkable transfers which Mr. Sherman F. Denton has been pre- paring for the last quarter-century, this particular set having been prepared especially for this book. Transfers of this sort were used as insets in Mr. Denton's work on the "Moths and Butterflies of the United States," pub- lished in a limited edition by J. B. Millet Company, Boston. The other plates not reproduced from photo- graphs are from drawings by Miss Mary E. Walker or Mr. W. I. Beecroft. In case the photographs are not of my own taking, credit is given beneath each. Two of my photographs have already appeared in "Seeing Nature First" and are here used by permission of its publishers, J. B. Lippincott Company. C. M. W. State Normal School, Lowell, Mass. CONTENTS PAGE Preface v List of Colored Illustrations xi List of Other Illustrations xiii PART I INTRODUCTION Butterfly Transformations 5 Butterflies AND Moths 13 The Scents OF Butterflies 15 Butterfly Migrations 16 Hibernation OR Winter Lethargy 17 Aestivation OR Summer Lethargy 21 Feigning Death IN Butterflies 22 Coloration OF Butterflies 24 Selectfve Color Sense IN Butterflies ... 32 Warning Coloration AND Mimicry .... 33 Heliotropism IN Butterflies 35 Parasitic Enemies OF Butterflies .... 40 Rex\ring Butterflies from Caterpillars ... 43 Photographing Butterflies 47 Butterfly Collections 49 vii viii CONTENTS PART II PAGE The True Butterflies — Superfamily Papilion- oidea 55 Parnassians {Parnassiinae) 5Q Swallowtails (Papilionidae) 57 Black Swallowtail; Giant Swallowtail; Blue Swal- lowtail ; Green-clouded Swallowtail ; Tiger Swallow- tail; Palamedes Swallowtail; Short-tailed Papilio; Zebra Swallowtail; Synopsis of the Swallowtails Whites, Orange-tips, and Yellows (Pieridae) . . 82 The Tribe of the Whites: White or Imported Cabbage Butterfly; Gray-veined White; Checkered White; Great Southern White; Synopsis of the Whites 83 The Tribe of the Orange-tips: Falcate Orange- tip; Olympian Orange-tip; Synopsis of the Orange- tips 92 The Tribe of the Yellows : Brimstone or Cloud- less Sulphur; Dog's-head; CloudedSulphur; Orange Sulphur; Pink-edged Sulphur; Black-bordered Yel- low; Little Sulphur; Dainty Sulphur; Synopsis of the Yellows 97 Nymphs {Nymphalidae) Ill The Tribe of the Fritillaries : Gulf Fritillary; Variegated Fritillary; Diana Fritillary; Regal Fritillary; Great Spangled Fritillary; Silver-spot Fritillary; Mountain Silver-spot; White Mountain Fritillary ; Meadow Fritillary ; Silver-bordered Frit- illary; Synopsis of the Fritillaries 115 The Tribe of the Crescent-spots: Baltimore CONTENTS ix PAGE Checker-spot; Harris's Checker-spot; Silver Crescent; Pearl Crescent; Synopsis of the Crescent- spots 135 The Tribe of the Angle- wings: Violet-tip; Hop- merchant or Comma; Gray Comma; Green Comma; Red Admiral or Nettle Butterfly; Painted Beauty; Painted Lady or Cosmopolite; Mourning- cloak; American tortoise-shell; White J Butter- fly or Compton Tortoise; Buckeye; Synopsis of the Angle-wings (I. Polygonias— II. Vanessids) . . 150 The Tribe of the Sovereigns: Viceroy; Banded Purple; Red-spotted Purple; Vicereine; Synopsis of the Sovereigns 192 The Tribe of the Emperors: Goatweed Emperor; Gray Emperor; Tawny Emperor; Synopsis of the Emperors 207 Meadow-browns or Satyrs {Agapetidae) . . . 214 Common Wood Nymph or Grayling; Southern Wood Nymph; Pearly Eye; Eyed Brown; "White Mountain Butterfly; Arctic Satyr; Little Wood Satyr; Other Meadow-browns; Synopsis of Meadow-browns Heliconians {Heliconidae) 229 Zebra Butterfly Milkweed Butterflies {Lymnadidae) .... 232 Monarch; Queen Snout Butterflies or Long-beaks {Lihytheidae) . 236 Snout Butterfly Metal-marks (Riodinidae) 239 Small Metal-mark; Large Metal-mark X CONTENTS PAGE Gossamer-wings (Lycaenidae) 240 The Tribe of the Hairstreaks: Great Purple Hairstreak; Gray Hairstreak; Banded Hairstreak; Striped Hairstreak; Acadian Hairstreak; Olive Hairstreak; Synopsis of the Hairstreaks . . . 242 The Tribe of the Coppers: Wanderer; American Copper; Synopsis of the Coppers 252 The Tribe of the Blues: Spring Azure; Scudder's Blue; Tailed Blue; Silvery Blue: Synopsis of the Blues 258 PART III The Skipper Butterflies — Superfamily Hes- perioidea 266 Giant Skippers {Megathymidae) 267 Yucca-borer Skipper Common Skippers (Hesperiidae) 268 The Tribe of the Larger Skippers : Silver-spotted Skipper; Long-tailed Skipper; Juvenal's Dusky- wing; Sleepy Dusky- wing; Persius's Dusky- wing; Sooty Wing 269 The Tribe of the Smaller Skippers : Tawny-edged Skipper; Roadside Skipper; Least Skipper . . 278 LIST OF COLORED ILLUSTRATIONS PAGE Viceroy Butterflies Visiting Strawberries {On Cover) The Regal Fritill.\ry Frontispiece The Carolina Locust 33 The Black Swallowtail 48 The Cynthia Moth 49 Giant Swallowtails 64 The Blue Swallowtail 65 Two OF the Swallowtails: Palamedes and Giant 66 The Green-clouded Swallowtail ... 67 Caterpillars of the Green-clouded Swal- lowtail 80 The Tiger Swallowtail 96 Imported Cabbage Butterfly .... 97 Clouded Sulphur Butterfly 112 The Zebra Swallowtail: Summer Form . 112-113 The Zebra Swallowtail Visiting Papaw Blossoms 112-113 Some of the Tribe of Yellows .... 113 Silver-spot Fritillary and Gulf Fritillary 128 Gulf Fritillary, Silver-bordered Fritil- lary, and Baltimore Checker-spot . . 129 The Hop Merchant 144 xi xii LIST OF COLORED LILUSTRATIONS PAGE Three Angle- wings (American Tortoise- shell, Red Admiral, Violet-tip): Upper Surface 160-161 Three Angle-wings (American Tortoise- shell, Red Admiral, Violet-tip): Lower Surface 160-161 The Painted Beauty 161 Three More Angle- wings: Buckeye, Painted Beauty, Cosmopolite .... 176 The Mourning-cloak 177 Some Common Skippers 192 The Stages of the Viceroy 193 Banded Purple, Red-spotted Purple, and Blue-eyed Grayling 208 Three Emperor Butterflies 209 The Zebra Butterfly 224 Monarch Butterfly, Chrysalis and Cater- pillar 241 Spring Azure, Falcate Orange-tip, Bronze Copper, and Great Purple Hair-streak . 256 Silver-spotted Skipper 273 LIST OF OTHER PLATES PAGE Swallowtail Butterfly Just out of Chrysalis 16 Tiger Swallowtail; Hammock Caterpillar . 17 Butterfly Feigning Death; Butterfly in Hi- bernating Position 32 Monarch Butterfly: Change from Cater- pillar to Chrysalis 32-33 Monarch Butterfly: Change from Chrysalis to Adult 32-33 Migration of Monarch Butterflies . . . 48-49 The Improved Open Vivarium 48-49 Black Swallowtail Visiting Thistle . . . 64-65 Imported Cabbage Butterfly, Magnified . . 64-65 Imported Cabbage Butterfly; Blue-eyed Grayling 81 Four-footed Butterflies: Viceroy and Mourning-cloak 145 Monarch Butterfly Resting; Flashlight Photograph OF MoNARCHS IN Migration . . 160 Photographs of a Pet Monarch Butterfly . 225 The Snout Butterfly; the Giant Swallowtail 240 Stages of the Gray Hair-streak 257 The Silver-spotted Skipper 272 BUTTERFLIES WORTH KNOWING BUTTERFLIES PART I INTRODUCTION In popular esteem the butterflies among the insects are what the birds are among the higher animals — the most attractive and beautiful members of the great group to which they belong. They are primarily day fliers and are remarkable for the delicacy and beauty of their membran- ous wings, covered with myriads of tiny scales that overlap one another like the shingles on a house and show an in- finite variety of hue through the coloring of the scales and their arrangement upon the translucent membrane run- ning between the wing veins. It is this characteristic structure of the wings that gives to the great order of butterflies and moths its name Lepidoptera, meaning scale- winged. In the general structure of the body, the butterflies re- semble other insects. There are three chief divisions: head, thorax, and abdomen. The head bears the principal sense organs; the thorax, the organs of locomotion; and the abdomen, the organs of reproduction. By examining a butterfly's head through a lens it is easy to see the principal appendages which it bears. Projecting forward from the middle of the top is a pair of long feelers or antennae. Each of these consists of short joints which 3 4 BUTTERFLIES in general may be divided into three groups: first, a few large joints at the base connecting the feeler with the head; second, many rather small joints which make up the prin- cipal length; third, several larger joints which make up the outer part or "club" of the antennse. In the case of the Skippers, there are in addition a number of small joints coming to a sharp point at the end of the club. Just be- low the insertion of the antennae on each side of the head are the large com- pound eyes, which are almost hemispherical. With a powerful glass, one can see the honey- comb-like facets, of which there are thou- sands, making up Butterfly Antennae, magnified. (From Holland) ■• t ■ i i each eye. J ust below the eyes there are two hairy projections, called the palpi, between which is the coiled tongue or sucking tube. {See plate, page 64-65.) Anatomically the thorax is divided into three parts — the prothorax, the mesathorax, and the metathorax; but the lines of division between these parts are not easily seen without denuding the skin of its hairy covering. The prothorax bears the first pair of legs. The mesathorax bears the front pair of wings and the second pair of legs. The metathorax bears the hind pair of wings and the third pair of legs. In many butterflies, the first pair of legs are so reduced in size that they are not used in walking. The abdomen is composed of eight or nine distinct rings or segments, most of which have two spiracles or breathing pores, one on each side. It also bears upon the end of the INTRODUCTION 5 body the ovipositor of the female or the clasping organs of the male. Butterfly Transformations The butterflies furnish the best known examples of in- sect transformations. The change from the egg to the caterpillar or larva, from the caterpillar to the pupa or chrysalis, and from the chrysalis to the butterfly or imago is doubtless the most generally known fact concerning the life histories of insects. It is a typical example of what are called com- plete transformations as distinguished from the manner of growth of grasshoppers, crickets, and many other insects in which the young that hatches from the egg bears Egg of Baltimore a general resemblance to the adult and in magnffLd.^cFrom , . , , . . , ,. Holland) wnicn there is no quiet chrysalis stage when the little creature is unable to eat or to move about. The Growth of the Caterpillars Caterpillars are like snakes in at least one respect: in order to provide for their increase in size they shed their skins. When a caterpillar hatches from the egg it is a tiny creature with a soft skin over most of its body but with rather a firm covering for its head. While we might fancy that there could be a considerable increase in size provided for by the stretching of the soft skin it is easy to see that the hard covering of the head will not admit of this. So the story of the growth of a caterpillar may be told in this way: 6 BUTTERFLIES A butterfly lays an egg upon a leaf. Some days later the egg hatches into a larva, which is the technical name for the second stage of an insect's life. In the case of the butterfly we call this larva a caterpillar. The little caterpillar is likely to take its first meal by eating the empty egg shell. This is a curious habit, and a really satisfactory explanation of it seems not to have been made. Its next meal is likely to be taken from the green tissues of the leaf, commonly the green outer surface only being eaten at this time. The future meals are also taken from the leaf, more and more being eaten as the larva gets older. After a few days of this feeding upon the leaf tissues the little caterpillar becomes so crowded within the skin with which it was born that it is necessary to have a larger one. So a new skin begins to form beneath the first one. Con- sequently the latter splits open in a straight line part way down the middle of the back just behind the head. Then the new head covering is withdrawn from the old one and the caterpillar wriggles its way out of the split skin and finds itself clothed in a new one. At first all of the tissues of the new skin are soft and pliable and they easily take on a larger size as the body of the caterpillar expands. A little later these tissues become hardened and no further expansion is possible. This process of skin-shedding is called moulting. The cast skin is often called the exuviae. The period of the caterpillar's life between the hatching from the egg and this moult is often called a stage or instar — that is, the caterpillar up to the time of this moult is living in the first caterpillar stage or instar. During the actual moulting the caterpillar is quite INTRODUCTION 7 active in freeing itself from the exuviae. But as soon as it is free it is likely to rest quietly for some hours while the tissues of the new skin are hardening. Then it begins feeding upon the leaf again and continues taking its meals at more or less regular intervals for several days. By that time it will again have reached its limit of growth within this second skin and the process of moulting must be re- peated. It takes place in the same way as before and the caterpillar enters upon the third instar of its larval life. This process of feeding and moulting is continued for several weeks, the number of moults being usually four. During the later stages the increase in size is more marked each time the skin is shed, until the caterpillar finally reaches its full growth as a larva and is ready for the won- derful change to the quiet chrysalis in which all its cater- pillar organs are to be transformed into the very different organs of the butterfly. , In the case of butterfly larvae one of the most interesting features of the growth of the caterpillar is that of the re- markable changes in colors and patterns of marking which the caterpillar undergoes. One who had not followed these changes would often be at a loss to recognize cater- pillars of slightly differing sizes as belonging to the same species. These changes commonly show a remarkable adaptation to the conditions of life, and generally tend to the concealment of the caterpillar upon its food plant. The stages of growth of the green-clouded swallowtail cater- pillar are illustrated on plate opposite page 80. Before each moult the caterpillar is likely to spin a silken web upon the leaf surface. It then entangles its claws in the web to hold itself in place while the skin is cast. (See plate, page 17.) BUTTERFLIES The Change to the Chrysalis {See plate, pages S2-33.) A week or ten days after the last moult of its caterpillar growth the larva commonly becomes full fed and ready to change to the chrysalis state. The details of the way in which this is accomplished vary greatly with different butterflies, as will be noted in the stories of many species later in this book. In general, however, the caterpillar provides a web of silk which it spins against some surface where the chrysalis will be secure and in this web it en- tangles its hind legs. Sometimes there is the additional protection of a loop of silk over the front end of the body. After the legs have become entangled the caterpillar hangs downward until the skin splits open along the median line of the back and gradually shrinks upward until it is almost free, showing as it comes off a curious creature which has some of the characteristic features of a chrysalis. It is seldom at this stage of the same shape as the chrysalis. When the caterpillar's skin is nearly off this chrysalis-like object usually wriggles its body quickly in a manner to entangle a curious set of hooks attached to the upper end in the web of silken thread. This hook-like projection is called the cremaster, and it serves a very important purpose in holding the chrysalis in position. Swallowtail Chrysalis, showing (b) the loop of silk over thorax. (After Riley) INTRODUCTION 9 As soon as the cremaster is entangled in the web the cast skin usually falls off and for a very short period the creat- ure hanging seems to be neither caterpillar nor chrysalis. It is in fact in a transition stage between the two, and it very soon shortens up and takes on the definite form of the chrysalis, the outer tissues hardening into the characteris- tic chrysalis skin. From the fact that this chrysalis skin shows man}'^ of the cliaracteristic featiu'es of the future butterfly it is evident that the change from the caterpillar to the butterfly really began during the life of the larva. The nature of the process by which this change takes place has long been a puzzle to scientists. For the making of a butterfly is one of the most wonderful phenomena in the outer world, and it has challenged the attention of many acute observers. Some two centuries ago the great Dutch naturalist, Swam- merdam, studied very carefully the development of many insects, especially the butterfly. He found that if he placed in boiling water a caterpillar that was ready to pupate or become a chrysalis, the outer skin could easily be removed, revealing beneath the immature butterfly with well-developed legs and antennae. From these observa- tions he was led to believe that the process of growth was simply a process of unfolding; that is, as Professor Packard has expressed it, "That the form of the larva, pupa, and imago preexisted in the egg and even in the ovary; and that the insects in these stages were distinct animals, contained one inside the other, like a nest of boxes or a series of en- velopes one within the other." This was called the in- casement theory and it was held to be correct by naturalists for nearly a century. It was discredited, however, about a hundred years ago, but not until another fifty 10 BUTTERFLIES years had passed was it definitely replaced by another and much more convincing theory propounded by Weismann. According to Weismann's theory, which is now well- estabhshed, the process of development internally is a much more continuous one than the external changes would indicate. So far as the latter are concerned we simply say that a caterpillar changes to a chrysalis and a chrysalis to a butterfly, the transition in each case requir- ing but a very short time. Internally, however, it has been going on almost continuously from the early life of the caterpillar. The various organs of the butterfly arise from certain germinal disks or "imaginal" buds, the word "imaginal" in this case being an adjective form of imago, so that the imaginal buds are really simply buds for the starting of growth of the various organs of the imago or adult. As the caterpillars approach the chrysalis period these imaginal buds rapidly develop into the various organs of the butterfly. This process is helped along by the breaking down of many of the tissues of the larva, this broken-down tissue being then utilized for the production of the new organs. About the time the chrysalis is formed this breaking-down process becomes very general, so that the newly formed chrysalis seems largely a mass of creamy material which is soon used to build up the various parts of the butterfly through the growth of the imaginal buds. The Change to the Butterfly {See plate, pages 32-33.) There is probably no phenomenon in the world of living creatures which has attracted more attention than the change of the chrysahs into the butterfly. It is not strange that this is so. We see upon a tree or shrub or wall INTRODUCTION 11 an inert, apparently lifeless object, having no definite form with which we can compare it with other things, having neither eyes nor ears nor wings nor legs — an object ap- parently of as little interest as a lifeless piece of rock. A few minutes later we behold it again and note with as- tonishment that this apparently inanimate being has been suddenly transformed into the most ethereal of the creat- ures of earth, with an exquisite beauty that cannot fail to attract admiration, with \^^ngs of most delicate struc- ture for flying through the air, with eyes of a thousand facets, with organs of smell that baflBe the ingenuity of man to explain, with vibrant antennae, and a slender tongue adapted to feeding upon the nectar of flowers — the most ambrosial of natural food. So it is not strange that this emergence of a butterfly has long been the theme both of poets and theologians and that it attracts the admiring attention of childhood, youth, and age. Fortunately, this change from chrysalis to butterfly may readily be observed by any one who will take a little trouble to rear the caterpillars or to watch chrysalids found outdoors. The precise method of eclosion, as we call this new kind of "hatching," varies somewhat with different species but in general the process is similar in all. Those chrysalids which have a light colored outer skin are especially desirable if we would watch this process. One can see through the semi-transparent membrane the developing butterfly within, until finally, just before it is ready to break out, the markings of the wings and body show distinctly. If at this time the chrysalis is placed in the sunshine it is likely to come out at once, so that you can observe it readily. It usually breaks apart over the head 12 BUTTERFLIES and the newly released legs quickly grasp hold of the empty skin as well as of the support to which it is attached. It then hangs downward with a very large abdomen and with the wings more or less crumpled up, but decidedly larger than when they were confined within the chrysalis. The wings, however, soon begin to lengthen as they are stretched out, probably through the filling of the space by the body juices. Commonly, the hind pair of wings be- come full size before the front ones. In a short time the wings attain their full size, the abdomen becomes smaller, through the discharge of a liquid called meconium, and the butterfly is likely to walk a few steps to a better position where it will rest quietly for an hour or two while body and wing tissues harden. After this it is likely to fly away to lead the free life of a butterfly. {See plate, page 16.) These changes from larva to chrysalis and from chrysalis to adult in the case of the Monarch Butterfly are illus- trated on the plates opposite pages 32-33. A Kttle study of these photographs from life will help greatly to an understanding of the process. Some very interesting observations have been made by Mr. J. Alston Moffat upon the method of the expansion of the wings. In summarizing his investigations he writes : " Wlien a wing is fully expanded, and for an hour or two after, the membranes can be easily separated. Entrance for a pin-point between them is to be found at the base of the wing where the subcostal and median nervures come close together. The membranes are imited at the costal and inner edges, which have to be cut to get them apart; but they are free at the outer angle. At that time the nervures are in two parts, half in one membrane and half INTRODUCTION 13 in the other, and open in the centre. The fluid which has been stored up in the pupa enters the winglet at the open- ing referred to, expanding the membranes as it passes along between them, and the nervures at the same time, and when it has extended to every portion of the wdng, then it is fully expanded. The expanding fluid is of a gummy consistency, and as it dries, cements the membranes together, also the edges of the half-nervures, and produces the hollow tubes with which we are so familiar." Butterflies and Moths The butterflies and moths both belong to the great order of scale-winged insects — the Lepidoptera. They are dis- tinguished, however, by certain general characteristics, which hold true for the most part in both groups. The butterflies fly by day; the moths fly by night. i\.ll of the higher butterflies go into the chrysalis state without making a silken cocoon, while most of the higher moths make such a cocoon. The bodies of the butterflies are usually slender, wliile those of the larger moths are stout. The antennae of the butterflies are generally slender and commonly en- larged at the tip into a miniature club. The antennae of the larger moths are commonly feathery or are long and slender, tapering gradually toward the tip. Butterfly wing scales, magnified. Holland) (From 14 BUTTERFLIES The characteristic features that distinguish a moth from a butterfly are well illustrated in the plate opposite page 49, which shows one of the largest and most beautiful moths in the world. It is the Cynthia moth. As may be seen, the newly emerged moth is resting upon the silken cocoon in which it spent its period as a pupa or chrysalis. This cocoon was attached by the caterpillar to the twig from which it hangs at the time it spun the cocoon. The feathered antennae, the hairy legs, the thick thorax, and large abdomen — all show very clearly in this side view of the moth. As will be seen, the wings are large and very suggestive of those of a butterfly and have the characteris- tic eye-spots toward the tip and the crescent marks in the middle, which are so often found on the wings of the larger moths. Some of these large moths on cloudy days occasionally fly during daylight and, by the uninitiated, they are often mistaken for large butterflies. One who will notice their structure, however, will readily see the characteristic features of the moth. In the caterpillar stage, there are no hard and fast differ- ences between the larvae of butterflies and those of the higher moths. In each case, the insect consists of a worm- like body, having a small head provided with biting jaws and simple eyes or ocelli. Back of the head are the three rings of the thorax, each of which bears a pair of jointed legs. Back of these three rings there are a considerable number of other body rings making up the abdomen, on the middle of wliich there are commonly four or five pairs of fleshy prolegs, not jointed but furnished at the tip with fine claws. At the hind end of the body there is another pair of prolegs similar in structure. INTRODUCTION 15 The Scents of Butterflies Many students of American butterflies have occasionally mentioned the fact that certain species seem to give off a distinct scent which has frequently been spoken of as a pleasing fragrance, suggesting sandalwood or some other aromatic odor. The general subject as exemplified by butterflies of other lands has been studied for many years by Fritz Miiller; and certain English entomologists have paid considerable attention to it. A translation of the Miiller publications and an excellent summary of our pres- ent knowledge of the subject is published in Dr. Longstaff's book on butterfly hunting. The odors given off by butterflies are divided into two principal kinds, namely: first, those which are repulsive to the senses of man, and evidently for the purpose of pro- tecting the butterflies from birds and other vertebrate enemies — these are found in both sexes; second, those which are evidently for the purpose of sexual attraction and confined to the male butterflies — these scents are usually attractive to the senses of man. The aromatic scents of the second group are generally produced by means of certain scales or hairs of many curious forms, which are scattered over the surface of the wings or are placed within certain special pockets, generally near the borders of the wings. These scales or hairs are called androconia. Some of them much magnified are represented in the picture above. Andrcxronia from wings of male butterflies 16 BUTTERFLIES Oiir knowledge of the scents given off by American butterflies is very fragmentary, and it is highly desirable that many more observations should be made upon the subject. If collectors generally would make careful notes, both in the field and upon the freshly killed butterflies at home, we ought soon to be able greatly to extend our knowledge. By holding the butterfly with a pair of for- ceps, one can often determine whether the fragrance is emitted. It is often helpful also to brush the hairs or tufts where the androconia are attached, using a small, dry camel's hair brush for the purpose. Butterfly Migrations Migration seems to be a general instinct in the animal world, developed when a species becomes enormously abundant. At such times this instinct apparently over- comes all others and the creatures move on regardless of obstacles and conditions that may mean certain death to the vast majority. Such migrations among mammals have often been recorded, one of the most notable ex- amples being that of the little lemmings which migrate at periodical intervals in a way which has often been de- scribed. Among the insects such migrations have been frequently noticed, and the phenomenon has apparently been observed oftener among the butterflies than in any other group. Entomological literature during the last hundred years contains a great many records of enormous flights of butterflies over long distances, extending even from Africa into Europe or from one part of America to another far remote. As such migration is likely to happen whenever a species becomes extremely abundant it prob- Photographed from life by A. H. Verrill See page 12 SWALLOWTAIL BUTTERFLY JUST OUT OF ITS CHRYSALIS. THE CHRYSALIS SKIN BELOW See page 72 TIGER SWALLOAVTAIL Photographed from life See page 7 THE HAMMOCK CATERPILLAR ON ITS HAMMOCK. INTRODUCTION 17 ably is Nature's way of providing for an extended food supply for the succeeding generations. That it results in the death of the great majority of the migrants is doubtless true, but it must lead to vast experiments in extending the geographic area inhabited by these species. Numer- ous examples of such migrating swarms will be found in the pages of this little book. (See plates, pages 1 7, 4^-49, 1 60.) The migrations thus considered are only exceptional occurrences. There is, however, a regularly recurring annual migration on the part of some butterflies which is also a phenomenon of extraordinary interest. The most notable example is that of the Monarch which apparently follows the birds southward every autumn and comes north- ward again in spring. There is much evidence to indi- cate that in some slight degree other butterflies have a similar habit, although the present observations are in- adequate to determine to what extent this habit has be- come fixed in most of these species. Hibernation or Winter Lethargy The ways in which butterflies spend the winter are al- ways of peculiar interest to the naturalist. Here are creatures with four distinct stages of existence, each of which has the possibility of carrying the species through the season of cold. It is necessary to learn for each in- sect which stage has been chosen for the purpose, and if possible to find the reasons for the choice. As a rule the related members of a group are likely to hibernate in a similar stage. Thus most of the Swallow- tails pass the winter as chrysalids while practically all the Angle-wings pass the winter as adults. This rule, how- 18 BUTTERFLIES ever, has many exceptions, for one will often find closely related species which dififer in the stage of hibernation. As one would expect, the conditions of hibernation vary greatly with the latitude. In the severe climate of the far north the conditions are likely to be more uniform than in the South where the milder climate permits greater va- riation to the insect. In some cases where a butterfly hibernates in only one stage in Canada it may pass the winter in two or more stages in Alabama or Florida. In many other orders of insects the egg is a favorite stage for hibernation. Even in the closely related moths it is often chosen by many species, but comparatively few butter- flies pass the winter in the egg stage. The little Bronze Copper may serve as one example of this limited group. The conditions as to hibernation by the larvae of butter- flies are very different from those of the egg. It has been estimated that probably half of all our species pass the winter in some stage of caterpillar growth. This varies all the way from the newly hatched caterpillar which hiber- nates without tasting food to the fully grown caterpillar which hibernates full fed and changes to a chrysalis in spring without eating anything at that time. A large pro- portion, however, feed both in fall and spring, going through the winter when approximately half grown. The Graylings and the Fritillaries are typical examples of butterflies which hibernate as newly hatched larvae. The eggs are laid in autumn upon or near the food plants and the caterpillars gnaw their way out of the shells and seek seclusion at once, finding such shelter as they may in the materials on the soil surface. In spring they begin to feed as soon as the weather permits and complete their growth from then on. INTRODUCTION 19 The half -grown caterpillars may hibernate either as free creatures under boards, stones, or in the turfy grass, or they may be protected by special shelters which they have provided for themselves in their earlier life. In the case of the latter each may have a shelter of its own or there may be a common shelter for a colony of caterpillars. Among the examples of those hibernating in miscellan- eous situations without special protection the caterpillars of the Tawny Emperor, the Gray Emperor, the Pearl Crescent, and some of the Graylings are examples. Among those which hibernate in individual shelters the Sovereigns, among which our common Viceroy is most familiar, are good examples. Among those which hibernate in a tent woven by the whole colony for the whole colony the Balti- more or Phaeton butterfly is perhaps the best example. {See plate, page 129.) The caterpillars that hibernate when full grown may be grouped in a way somewhat similar to those which are half grown. Many species simply find such shelter as they may at or near the soil surface. The Clouded Sulphur is a good example of these. Others pass the winter in in- dividual shelters made from a leaf or blade. Several of the larger Skippers are good examples of this condition. So far as I know none of our species pass the winter in colonial shelters when full grown. It would be natural to suppose that the great majority of butterflies would be likely to hibernate in the chrysalis state. Here is a quiet stage in which the insect is unable to move about or to take any food, in which it seems en- tirely dormant and as a rule is fairly well hidden from the view of enemies. We find, however, that only a rather small proportion of our butterflies has chosen this stage 20 BUTTERFLIES for survival through the winter. The most conspicuous examples are the Swallowtails, nearly all of which hiber- nate in the chrysalis stage. Other examples are the va- rious Whites, the Orange-tips, and isolated species like the Wanderer, and the Spring Azure and the American Copper. Practically all the butterflies that pass the winter as chrysalids have a silken loop running around near the middle of the body which helps to hold them securely through the long winter months. Apparently none of those chrysalids which hang straight downward are able to survive the winter. An adult butterfly seems a fragile creature to endure the long cold months of arctic regions. Yet many of our most beautiful species habitually hibernate as adults, finding shelter in such situations as hollow trees, the crevices in rocks, the openings beneath loose bark or even the outer bark on the under side of a large branch. It is significant that most of the adult- wintering Angle- wings are northern rather than southern species, some of them being found in arctic regions practically around the world. One of the few southern forms that hibernates as an adult is the Goat- weed Emperor. (See plate, page 209.) These examples are all cases of true hibernation in a lethargic condition. There are certain butterflies, how- ever, which pass the winter as adults that remain active during this period. Obviously this is impossible in lati- tudes where the winter is severe, and it involves migration to a warmer climate. The one notable illustration of this is the Monarch butterfly which apparently flies southward to the Gulf states at least and there remains until spring, when individuals come north again. The southward mi- gration may be begun in Canada when the butterflies INTRODUCTION 21 gather together in enormous flocks that remind one of the gathering of the elans with the migrating birds. This is one of the least understood of insect activities but it has been observed so often and over so long a period of years that there seems to be no questioning the general habit. Like everything else in relation to living things there are numerous variations in the prevailing modes of hiberna- tion. In the case of many species one can find combina- tions of two or more stages in which the winter is passed. Probably if we could observe with sufficient care we might be able to find somewhere examples of almost any con- ceivable double combination — as egg with larva or chrys- alis or adult — the insect hibernating in two of these stages. Many examples are known in which both chrysalis and adult of the same species pass the winter and also of those in which young and well-grown larvae pass the winter. As one would expect, the conditions as to such combina- tions are likely to be more variable in southern than in northern regions. Notwithstanding all the attention which has been paid to butterfly life-histories there is still some uncertainty in regard to the hibernation of many of our species. One of the most interesting series of observations which a young naturali^* could undertake would be to learn positively how each species of butterfly in his locality passes the winter. Aestivation or Summer Lethargy In some species of butterflies there is a special adaptation to passing through the hottest part of the summer season in a state of lethargy which is suggestive of the torpor of 22 BUTTERFLIES the hibernating period. This phase of butterfly existence has not been extensively studied and there are indications that it exists more generally than has been commonly sup- posed. It has been noticed even in northern New England that some of the Angle-wings seek shelter and become lethargic during August. Apparently this is an adaptation to single broodedness, helping to carry the species through the year without the exhaustion incident to the con- tinued activity of the butterfly. In more southern regions, especially In the hot, dry climates where vegetation withers in midsummer, it is well known that some caterpillars become lethargic, remain- ing inactive until the fall rains start vegetation into growth. The Orange-sulphur butterfly is a good example of this. This summer lethargy offers excellent opportunity for careful study. Any observer who finds a butterfly hidden away in summer under boards, the bark of a tree, or in a stone pile should look carefully to see what species it is and how the butterfly behaves. Such observations should be sent to the entomological journals in order that our knowl- edge of the subject may be increased. Feigning Death The fact has long been noticed that various butterflies have the habit at times of feigning death and dropping to the ground where they may lie motionless for a consider- able period. This habit is most easily observed in some of the Angle-wings, especially those which hibernate as adults. Those species have the under surfaces of their wings colored in various bark-picturing patterns and ap- INTRODUCTION 23 parently live through the winter to some extent, resting beneath the bark of large branches or upon the trunks of trees. Many of them also secrete themselves in hollow trees or beneath loose bark or in board piles or stone walls. It is probable, however, that during the long ages when these insects were adapting themselves to their life con- ditions, before man interfered with the natural order and furnished various more or less artificial places for hiberna- tion, these butterflies rested more generally upon the un- der side of branches than they do now. Even in warm weather when one of these butterflies is suddenly disturbed it is likely to fold its legs upon its body and drop to the ground, allowing itself to be handled with- out showing any signs of life. This habit is doubtless of value, especially during hibernation or possibly during the summer lethargy or aestivation, the latter a habit which may be more general among these butterflies than is now supposed. As the insect lies motionless upon the ground it is very likely to blend so thoroughly with its surround- ings that it becomes concealed, and any bird which had startled it from the branch above would have difficulty in finding it. Some very interesting observations have been made upon the death-feigning instincts of various other insects, especially the beetles. But no one so far as I know has yet made an extended study of the subject in relation to our American butterflies. It is an excellent field for investiga- tion and oflFers unusual opportunities for photographic records. One of the pictures opposite page 32 shows a photograph which I took of a Mourning Cloak as it was thus playing 'possum. This species exhibits the instinct to a marked degree. 24 BUTTERFLIES C0LORA.T10N The caterpillars of butterflies and moths form a large part of the food of insect-eating birds. These caterpillars are especially adapted for such a purpose and in the econ- omy of nature they play a very important part in keeping alive the feathered tribes. During the long ages through which both birds and insects have been developing side by side, there have been many remarkable inter-relations es- tablished which tend on the one hand to prevent the birds from exterminating the insects and on the other to prevent the insects from causing the birds to starve. The most important of these, so far as the caterpillars are concerned, are the various devices by which these insects protect themselves from attack, by hiding away where birds are not likely to find them, by clothing their bodies with spiny hairs, by other methods of rendering themselves dis- tasteful, or by various phases of concealing coloration. On the whole, the examples of the latter are not so numer- ous or so easily found in the case of the larvae of butter- flies as in those of moths. Perhaps the basal principle of concealing coloration is the law of counter-shading, first partially announced by Prof. E. B. Poulton, and later much more elaborately worked out by Mr. Abbott H. Thayer, and discussed at length by Mr. Gerald H. Thayer in his remarkable volume, " Concealing Coloration in the Animal Kingdom." The law of counter-shading is tersely stated in these words: "Animals are painted by nature darkest on those parts which tend to be most lighted by the sky's light and vice versa.'* As this law works out on most animals that live INTRODUCTION 25 on or near the ground, the upper part of the body exposed to the direct light from above is dark; and the under part, shut off from the upper Hght and receiving only the small reflection from below, is enough lighter to make the ap- pearance of the creature in its natural environment of a uniform tone from back to breast. Nearly all caterpillars illustrate this law of counter- shading. If they are in the habit of feeding or resting with their feet downward the back will be darker and the un- der side lighter, but if they are in the habit of feeding or resting in the opposite position these color tones will be reversed. One can find examples of such conditions al- most any summer's day by a httle searching of trees or shrubs. This law of counter-shading, however, is really only the basis for the coloration of caterpillars or other animals. It tends, chiefly, to make the creature appear as a flat plane when seen from the side, and may be said in a way to pre- pare the canvas upon which Nature paints her more dis- tinctive pictures. A great many examples of color mark- ings that tend to conceal the caterpillar amid its natural surroundings may be found by any one who will study the subject and it offers one of the most interesting fields for investigation. The chapter on caterpillars in the above- mentioned book by Mr. Thayer should serve as a starting point for any one taking up the subject. Butterflies differ from caterpillars and from most other animals in the fact that their coloring is chiefly shown upon the flat surfaces of the wings. Consequently, there is less opportunity for the various phases of counter-shading which is so commonly shown in the larger caterpillars. The bodies of nearly all butterflies do exhibit this phenom- 26 BUTTERFLIES enon, but these bodies are relatively so small that counter- shading plays but a little part in the general display. Upon the outstretched membranes of the butterflies' wings Nature through the long ages of development has painted a great variety of pictures. Those which tend to protect the insect by concealment amid its surroundings are most commonly spread on the under surface of the wings. Especially is this true in the case of those species which pass the winter as adults or which have the habit of resting upon the bark of trees, the sides of rocks, or the surface of the ground. We here find some of the most interesting examples of obliterative coloring that occur in nature. Some butterflies have taken on the look of tree bark, others the sombre appearance of weathered rocks, while still others are painted with the images of flowerets and their stems. Dazzling and Eclipsing Colors Many of the butterflies, especially the Angle-wings, which are marked on the under surface in various pro- tective colors, are admirable examples of that phase of animal coloring which is spoken of as dazzling coloration. This is apparently one of the most important protective devices to be found in Nature and the vahdity of it is now generally conceded by naturalists. One phase of it, which may be called eclipsing coloration, seems to have been first definitely formulated by the late Lord Walsingham, a famous English entomologist who enunciated it in an ad- dress as president of the Entomological Society of London. The most significant paragraphs in that address were these: " My attention was lately drawn to a passage in Herbert Spencer's 'Essay on the Morals of Trade.' He writes: INTRODUCTION 27 * As when tasting different foods or wines the palate is dis- abled by something strongly flavored from appreciating the more delicate flavor of another thing afterward taken, so with the other organs of sense a temporary disability follows an excessive stimulation. This holds not only with the eyes in judging of colors, but also with the fingers in judging of texture.' "Here, I think, we have an explanation of the principle on which protection is undoubtedly afforded to certain in- sects by the possession of bright coloring on such parts of their wings or bodies as can be instantly covered and con- cealed at will. It is an undoubted fact, and one which must have been observed by nearly all collectors of in- sects abroad, and perhaps also in our own country, that it is more easy to follow with the eye the rapid movements of a more conspicuous insect soberly and uniformly colored than those of an insect capable of changing in an instant the appearance it presents. The eye, having once fixed itself upon an object of a certain form and color, conveys to the mind a corresponding impression, and, if that impression is suddenly found to be unreliable, the instruction which the mind conveys to the eye becomes also unreliable, and the rapidity with which the impression and consequent instruction can be changed cannot always compete suc- cessfully with the rapid transformation effected by the in- sect in its effort to escape." Lord Walsingham then goes on to suggest that this in- termittent play of bright colors probably has as confusing effect upon birds and other predaceous vertebrates as upon man; and that on this hypothesis such colors can be accounted for more satisfactorily than upon any other yet suggested. Since then the significance of this theory has 28 BUTTERFLIES been repeatedly pointed out by Professor Poulton, Mr. Abbott H. Thayer, and various other authorities upon animal coloring. The terms dazzling and eclipsing have been applied to the phenomenon. Shortly after Lord Walsingham propounded this theory I called attention* to its fitness in explaining some of the most interesting color phases shown by American insects, notably the moths and locusts which have brilliantly colored under wings and protectively colored upper wings. The animals of the north show numberless color phases of interest. One of the most curious of these is exhibited by several families of insects in which the outer wings are protectively colored in dull hues and the under wings brightly colored. For example, there are many species of moths belonging to the genus Catocala found through- out the United States. These are insects of good size, the larger ones measuring three inches in expanse of wings, and the majority of them being at least two thirds that size. Most of them live during the day on the bark of trees, with their front wings folded together over the back. The colors and markings of these wings, as well as of the rest of the exposed portions of the body, are such as to assimilate closely with the bark of the tree upon which the insect rests. In such a situation it requires a sharp eye to detect the presence of the moth, which, unless disturbed, flies only at night, remaining all day exposed to the attacks of many enemies. Probably the most important of these are the birds, especially species like the woodpeckers, which are constantly exploring all portions of the trunks of trees. *Popular Science Monthly, 1898, "A Game of Hide and Seek." Reprinted m the Insect World, 1899. INTRODUCTION 29 The chief beauty of these Catoealas, as they are seen spread out in the museum cabinet, Hes in the fact that the hind wings, which, when the moth is at rest in hfe, are con- cealed by the front ones, are brightly colored in contrasting hues of black, red, and white in various brilliant combina- tions. These colors, in connection with the soft and blended tones of the front wings, make a very handsome insect. It is easy to see that when one of these Underwing Moths is driven to flight by a woodpecker or other bark- searching bird it would show during its rapid, irregular flight the bright colors of the under wings which would be instantly hidden upon alighting and the very different coloring of the upper wings blending with the bark would be substituted. Consequently, the bird would be very likely to be baflSed in its pursuit. Coloration of Locusts On the rocky hills and sandy plains of New England there are several species of grasshoppers or locusts that also illustrate these principles. If you walk along a strip of sandy land in summer, you start to flight certain locusts which soon alight, and when searched for will be found closely to assimilate in color the sand upon which they rest. On a neighboring granite-ribbed hill you will find few if any of this species of locust, but instead there occur two or three quite different species, which when at rest closely, resemble the lichen-covered rocks. This resem- blance is very striking, and is found in all stages of the in- sect's existence. If now you go to a lowland meadow, still another color phase will be found to prevail — the green grass is swarming with the so-called "long-horned" grass- 30 BUTTERFLIES hoppers, which are green throughout with hnear bodies, and long, slender legs and antennae. Each of these three groups of insects is adapted to its particular habitat. All are constantly persecuted by birds, and have been so persecuted for unnumbered ages in the past. In every generation the individuals have varied, some toward closer resemblance to environment, others in an opposite direction. The more conspicuous insects have been constantly taken, and the least con- spicuous as constantly left to reproduce. Were the three groups to change places to-day, the green grasshoppers from the meadows going to sandy surfaces, the sand- colored locusts going to rocky hills, and the "mossbacks" from the hills to the lowland meadows, each would be- come conspicuous, and the birds would have such a feast as is seldom spread before them. The species living on sand and rocks are often "flushed" by birds. Those which flew but a few feet would be likely to be captured by the pursuing bird; those which flew farther would stand a better chance of escaping. Similarly, those which flew slowly and in a straight line would be more likely to be caught than those which flew rapidly and took a zigzag course. As a consequence of the selection thus brought about through the elimination of those which flew slowly along the straight and narrow way that led to death, you will find that most locusts living in exposed situations when startled fly some distance in a rapid, zigzag manner. But still another element of safety has been introduced by some species of these locusts through the adoption of the color tactics of the Catocala moths. The under wings of the common Carolina locust — the species most abund- INTRODUCTION 31 ant along the highway — are black, bordered with yellowish white. The base of the hind wings of a related species living on the Western plains is bluish, while in the large coral-winged locust of the Eastern states the hind wings are red, bordered with black. In nearly all of the species of these locusts frequenting open localities where they are liable to disturbance by birds or other animals, the hind wings exhibit contrasting colors in flight. Most of them also fly in a zigzag line, and alight in a most erratic man- ner. Many times I have had difficulty in determining the exact landfall of one of these peculiar creatures, and I be- lieve Lord Walsingham's suggestion is well exemplified in them. (See page 33.) The most famous example of a combination of this dazzling coloring of the upper wing surface with a definite protective coloring of the under wing surface is the Kallima butterfly which is illustrated in almost every book dealing with animal coloration. The under wing surface bears a striking resemblance to a leaf and the hind wings project to form a tail which looks like the petiole of the leaf, and there is also a mark running across the wings which mimics the midrib. When the butterfly is flying the brilliant colors of the upper surface are visible, but when it alights these are instantly replaced by the sombre tone of the under surface, so that apparently the insect com- pletely disappears and in its place there is only a leaf attached to a branch in a most natural position. In Dr. Longstaff's book there is an illustration of another tropical butterfly, Eronia cleodora, which resembles on its under surface a yellow disease-stricken leaf but on its upper surface gives a brilliant combination of black and white. This insect alights upon the leaves which it resembles 32 BUTTERFLIES and is a striking example of both dazzling and mimicking coloration. Many of our own butterflies, notably the Angle-wings, are excellent examples of a similar combination. In flight they reveal conspicuous colors which are instantly hidden upon alighting and then one only sees the bark-like or dead leaf -like under surface as may be seen in the plate opposite pages 160-161. The iridescence upon the upper wing surface of many butterflies, whose under wing surface is colored in concealing tones, is doubtless also of great use to the insect in a similar way. There is a splendid opportunity here for some observer to study this phase of butterfly activity and to get photographs of the insects amid their natural sur- roundings. In their book upon " Concealing Coloration" the Messrs. Thayer have called attention to many interesting phases of dazzling coloration. They show that bright marks like the eye-spots or ocelli, which form so prominent a feature on the wing surfaces of many butterflies, really helped to conceal the insect amid its natural surroundings, by draw- ing the eye away from the outlines of wings and body so that the latter tend to disappear. Their discussion of this subject opens up another vast field for outdoor observa- tions of absorbing interest, in which there is great need for many active workers. Selective Color Sense One who collects the Underwing moths soon discovers that the light colored species which resemble the bark of birch trees are likely to be found upon the trunks of those trees, and that the dark colored kinds which resemble the Sec piiyc 2-j BUTTERFLY FEIGNING DEATH, HANGING TO BARK BY ONE FOOT >(< piKJC 17 BUTTERFLY IN HIBERNATING POSITION Caterpillar feeding upon leaf of milkweed Caterpillar hung up for the change to the chrysalis The transition stage The chrysalis THE MONARCH BUTTERFLY: CHANGE FROM CATERPILLAR TO CHRYSALIS. Photographs from life (See pages 8-10, 233) Chrysalis showing butterfly ready to emerge e empty chrvsalis Butterfly just out of chrysalis Side view a little later THE MONARCH BUTTERFLY: THE CHANGE FROM CHRYSALIS TO ADUT.T. PhotoiiTn])hs from life {^cefagcs 10-13. '23'>) See page SO THE CAROLINA LOCUST Above, with wings expaiulod as in flight INTRODUCTION 33 bark of maple trees are likely to be found upon the trunks of these. Obviously, were this not true the protective coloring would avail but little and it is evident that these moths are able to select a background which is of advant- age in helping to conceal them. There is much evidence to show that in a similar way the butterflies are able by means of a well-developed color sense to select the places where they alight. One of the most notable examples is that of a South American species, Peridromia feronia. This is a silvery gray butterfly which alights head downward upon the bark of certain palm trees that have silvery gray stems and remains there 'with its wings fully expanded so that it utilizes the background in much the same way that the Underwing moths do. "When disturbed they will return to the same tree again and again." One who will observe the habits of our Angle- wings and other butterflies which have obliterative coloring of the under wing surface can easily learn that these insects select rather carefully the places where they alight. It will be found that as a rule each species utilizes a back- ground that blends with its own coloring. It is probable that this habit is much more common in other groups of but- terflies than has been realized. Much evidence of this sort has been collected regarding the butterflies of Europe and other countries, as well as near our own borders in America. Warning Coloration and Mimicry The colors of a great many animals, including a con- siderable percentage of American butterflies and their larvae, have been commonly explained by the theory of 34 BUTTERFLIES warning colors. According to this theory animals which were for any reason not edible by birds and mammals have developed various striking combinations of color such as black and yellow, red and black, or black and white, in order to advertise to their foes their inedible qualities. This theory has been very generally accepted by naturalists and will be found expounded at length in many books pub- lished during the last quarter century. The whole subject of the validity of warning coloration has recently been brought up for reconsideration by the il- luminating investigations of Mr. Abbott H. Thayer and discussed at length in the book upon " Concealing Colora- tion" already mentioned. In an appendix to this book dated 1908 Mr. Thayer states that he no longer holds the belief that "there must somewhere be warning colors." He has convincingly shown that a large proportion of the animals which were supposed to be examples of this theory are really illustrations of concealing coloration. But there yet remain various facts which have been conclusively proven that apparently require the theory of warning colors to explain them. Here is another field in which there is a real need for much careful investigation under conditions that are rigidly scientific. Along with the theory of warning coloration the theory of mimicry has been propounded. According to this if a butterfly in a given region shows warning coloration, having developed such coloration because it is distasteful to birds and mammals, it may be mimicked by another butterfly in the same region belonging to another group, the latter butterfly being edible, but benefiting by its re- semblance to the distasteful species, because birds or mammals mistake it for the latter and do not attempt to INTRODUCTION 35 catch it. The most notable example of such mimicry in North America is that of the Monarch butterfly, which is supposed to be the distasteful species, and the Viceroy butterfly, which is supposed to mimic it. Several other instances of mimicry are found among our own butterflies, while in South America, Africa, and Asia there are number- less examples. Helioteopism It has long been known that the green surfaces of plants respond to the stimulus of the sun's rays in a most remark- able manner. This response has commonly been called heliotropism and it has been carefully studied by botanists all over the habitable world. More recently, the fact has been observed that many animals respond in certain defi- nite ways to the stimulus of direct sunshine and the same term has been applied in this case. Very little attention has been given to the subject of heliotropism until within a few recent years. But the observations which have been made by Parker, Longstaff, Dixey, and others open up a most interesting field for further observation. An ad- mirable summary of our present knowledge of the subject has been published by Dr. Longstaff in his book "Butterfly Hunting in Many Lands." One of the earliest observations upon this subject was that published in my book "Nature Biographies" which ap- peared in June, 1901, concerning the habit in the Mourning Cloak: "On a spring-like day early in November (the 8th) I came across one of these butterflies basking in the sun- shine upon the ties of a railway track. It rested with its wings wide open. On being disturbed, it would fly a short 36 BUTTERFLIES distance and then alight, and I was interested to notice that after alighting it would always turn about until the hind end of its body pointed in the direction of the sun, so that the sun's rays struck its wings and body nearly at right angles. I repeatedly observed this habit of getting into the position in which the most benefit from the sun- shine was received, and it is of interest as showing the ex- treme delicacy of perception toward the warmth of sun- sliine which these creatures possess." A httle later, some very elaborate observations were made upon this habit of the Mourning Cloak by Prof. G. H. Parker of Harvard University. Professor Parker noticed that during the warm spells in winter the butter- flies came out of their hiding places and after alighting, al- ways placed themselves with their heads away from the di- rection of the sun and their bodies lying nearly at right angles to the sun's rays. By experiment, he found that they adjusted themselves to this position as soon as they were fully exposed to direct sunshine, even if at the time of alighting they were in a shadow. He found that this movement was a reflex action through the eyes, for when the eyes were blinded no such adjustment took place. He called it negative heliotropism. Dr. Longstaff uses the term orientation for this adjust- ment of the butterfly to the sun's rays and he finds it is a very general habit, especially with the Angle- wings, for the butterfly thus to orient itself after alighting, in such a way that the hind end of the body points toward the sun. This occurs not only with those species which keep their wings spread open when they alight but also with those in which the wings are closed together and held in a vertical po- sition on alighting. INTRODUCTION 37 Various explanations of this phenomenon have been ofifered but apparently none of them are yet generally accepted. Were the habit confined to butterflies like the Mourning Cloak, it would seem easy to prove that a main advantage was found in the benefit derived from the heat rays of the sun. Were it confined to those species which always fold their wings on alighting, it would seem easy to believe that it was a device for reducing the shadow cast by the insect to its lowest terms. It has also been suggested that the habit is for the purpose of revealing to the fullest extent the markings of the butterfly. Evidently there is here an ample field for further investigation before definite conclusions are reached. List and Shadow Observations Another field for most interesting studies upon the habits of living butterflies has been opened up by the very interesting discussion of list and shadow in Colonel G. B. Longstaff's fascinating book, "Butterfly Hunting in Many Lands." He there summarizes his numerous observations upon butterflies in various localities which he has seen to lean over at a decided angle when they alight. He de- fines ^^ List" as "an attitude resulting from the rotation of the insect about its longitudinal axis, as heliotropism re- sults from a rotation about an imaginary vertical axis at right angles to this." The name is adapted from the sailors' term applied to a vessel leaning to one side or an- other in a storm. Apparently this interesting habit was first called to the attention of European entomologists by an observation of 38 BUTTERFLIES Colonel C. T. Bingham made in 1878, but not published until long afterward. The observation was this: " The Melanitis was there among dead leaves, its wings folded and looking for all the world a dead, dry leaf itself. With regard to Melanitis, I have not seen it recorded any- where that the species of this genus when disturbed fly a little way, drop suddenly into the undergrowth with closed wings, and invariably lie a little askew and slanting, which still more increases their likeness to a dead leaf cas- ually fallen to the ground." Long before this was printed, however, a similar habit had been observed by Scudder in the case of our White Mountain butterfly {Oenis semidea). But this species is so exceptional in its habitat that the habit seems to have been considered a special adaptation to the wind-swept mountain top. The possibility of its being at all general among the butterflies in lowlands seems to have been over- looked. The observations recorded by Longstaff relate chiefly to various members of the Satyrid group. For example, a common Grayling, Satyrus semele, was watched many times as it settled on the ground. As a rule three motions are gone through in regular sequence: the wings are brought together over the back; the fore wings are drawn between the hind wings; the whole is thrown over to right or left to the extent of thirty, forty, or even fifty degrees. This habit, of course, is of advantage to the insect. It seems possible that the advantage might be explained in either of two ways: first, the leaning over on the ground among grasses and fallen leaves might help to render the disguising coloration of the insect more effective, the large ocelli serving to draw the eye away from the outline INTRODUCTION 39 of body and wing; second, the listing of the butterfly to- ward the sun tends to reduce the shadow and to hide it be- neath the wings. There is no doubt that when a Grayhng butterfly lights upon the ground in strong sunshine the shadow it casts is more conspicuous than the insect itself and the hiding of this might be of distinct advantage in helping it to escape observation. It is significant that in England the butterflies observed appear to lean over more frequently in sunshine than in shade. An observation of Mr. E. G. Waddilove, reported by Colonel Longstaff, is insteresting in this connection: *' A Grayling settled on a patch of bare black peat earth, shut up its wings vertically, and crawled at once some two yards to the edge of the patch to where some fir-needles, a cone or two, and a few brittle twigs were lying, and then be- coming stationary threw itself over at an angle of some forty-five degrees square to the sun. It thus became quite indistinguishable from its surroundings." Apparently, some of the Angle-wings may have the same habit, for in Barrett's " Lepidoptera of the British Islands," there is a note in regard to Grapta C-album to the effect that it is fond of sunning itself in roads, on warm walls, or on the ground upon dead leaves in sheltered valleys. "Here, if the sun becomes overclouded, it will sometimes close its wings and almost lie down, in such a manner that to distinguish its brown and green marbled under side from the dead leaves is almost impossible." Here is a most fascinating opportunity for American observers to determine definitely the facts in regard to our numerous species of butterflies that may show this habit. An observer with a reflex type of camera might easily be able to get pictures that would be of great value in helping 40 BUTTERFLIES to determine the principal facts in regard to the subject. Our common Graylings and numerous species of Angle- wings are so abundant and easily observed that they offer splendid opportunities to any one who will undertake a serious study of the subject. Parasitic Enemies All three of the earlier stages of butterflies — egg, larva, and chrysalis — are subject to attack by various parasitic insects which develop at the expense of the host. Such parasites are probably the most important check upon the increase of butterflies, and along with birds, mammals, and bacterial diseases, they help to keep up that balance of nature which in the long run maintains a surprising uni- formity in the numbers of each kind of butterfly. For the most part these insect parasites are small four- winged flies, although many of them are two-winged flies. In either case the life stages show a series of changes much like those of the butterflies themselves. Each parasite exists first as an egg, second as a larva, third as a pupa, and fourth as an adult fly. The larval stage, however, is simply that of a footless grub which Hves within the body of its victim absorbing its life blood and gradually kilhng it. The parasites of butterfly eggs are legion. They are tiny flies whose life-story in briefest summary is this : The butterfly lays an egg. The parasite fly finds this egg soon after it is laid, and pierces the shell with her tiny, sharply pointed ovipositor and deposits inside of the shell her own microscopic egg. This egg within the egg soon hatches into a curious little larva that develops at the expense of the contents of the butterfly egg shell, and soon absorbs INTRODUCTION 41 the whole of them. The parasite larva now changes to a pupa which a httle later changes again to an adult fly like the one that laid the parasite egg in the beginning. Of course the butterfly egg never hatches into a caterpillar. One of the most interesting questions in regard to these egg parasites is this: How does the tiny parasitic fly find the newly laid egg.^^ One would think that the proverbial search for a needle in a haymow would be an easy task compared with that of a fly about as large as the head of a pin finding a butterfly egg of similar size upon some part of one of the millions of leaves upon the trees and shrubs in field and forest. Yet the search is successful, as every one who has tried to get caterpillars from eggs found out of doors will testify. On a later page in this book, in con- nection with the story of the life of the Mourning Cloak butterfly, I have recorded some observations upon the little parasite which seemed to have been riding around upon the body of the butterfly waiting for her to lay her eggs. For one parasite upon the eggs of butterflies, there probably are dozens that attack the caterpillars. A large proportion of the butterfly larvae brought in from out- doors, especially those which are half-grown or more, will yield not butterflies but parasites. This is the experience of practically every one who attempts to rear these in- sects, and it emphasizes the value of the advice that in order to get fine specimens, it is desirable to rear them from eggs laid by butterflies beneath netting or in cages. The life-histories of the parasites that attack cater- pillars vary greatly. The simplest are those of the large Ichneumon flies : The mother fly lays an egg beneath the skin of the caterpillar. The egg hatches into a larva that absorbs the fatty parts of the body of the caterpillar. 42 BUTTERFLIES gradually growing larger and larger until at last it reaches a length of possibly an inch. By this time it is likely to have absorbed so large a part of the inside of the cater- pillar that the latter dies. The parasite larva now changes to a pupa, either inside or outside the skin of the cater- pillar, and a little later changes again to an adult Ichneu- mon fly. In the case just given, one egg only was deposited within the skin of the caterpillar. In many others, however, a large number of eggs may be so deposited by a single fly. A special group of Ichneumon flies, called the Microgast- ers, contains many parasites that have this peculiarity. The Microgaster larvae on coming forth from the cater- pillar have the habit of spin- ning tiny cocoons within Tachlnid ParasUe; ^^fly; b. pupartum, which they chaUgC tO pupaC. By collecting some cabbage worms which are nearly full grown, and keeping them in a glass jar one can generally get a considerable number of these Microgaster cocoons and rear the flies from them. Another group of caterpillar parasites is still more mi- nute. They are called the Chalcid flies. Their life-his- tories are full of interest, and might easily furnish oppor- tunity for a long lifetime of study and experiment. One is likely to get hundreds of these Chalcid flies from a single caterpillar. Another interesting group of parasites is that of the two- winged Tachina flies (see cut on this page). The life- story of some of these is comparatively simple: a buzzing INTRODUCTION 43 fly, looking much like a large housefly, lays a small whitish egg upon the skin of a caterpillar. This egg is glued tightly and is large enough to be readily seen by the un- aided eye. It hatches into a tiny larva that eats its way through the part of the shell glued to the caterpillar's skin, and through the latter at the same time. So the newly hatched Tachina larva finds itself in the body of its cater- pillar host. It lives there, absorbing the fatty juices around it until at last it either kills or stupefies its un- fortunate victim. It has then become full grown as a larva, and its last larval skin hardens into a brown pupa- case within which the little creature changes into a pupa. It may or may not have burrowed through the skin of the caterpillar before this happened. A little later the pupa changes to a Tacliina fly which breaks apart the pupa case and flies out into the world. It has lately been found, however, that many Tachinids have much more complicated life-histories than this. I have already discussed some of the more important of these in my book entitled, "Seeing Nature First" (pages 150-158). One can frequently rear parasites from the chrysalids of butterflies, but in many cases it is probable that these be- gan their parasitic development in the caterpillars, which were able to change to chrysalids before being killed. In some cases, however, the chrysalids seem to be attacked, especially by certain Ichneumon flies. Rearing Butterflies From Caterpillars There are few tilings in the world more interesting to watch than the wonderful changes which a moth or butter- 44 BUTTERFLIES fly goes through in the course of its life. You find on a tree or shrub a wormlike caterpillar. You take it in charge, placing it in a box or jar where you can provide leaves for its food and soon it either spins around itself a silken shroud, thus hiding from your sight, or else it simply seems to change to a lifeless object without eyes or wings or legs, unable to move about and motionless, save for a slight wriggle when you touch it. Yet if you keep the shroud or the mummy-like object for two or three weeks you are likely to see a beautiful moth come from the shroud or a glorious butterfly break out of the mummy case. {See plate, page 4-9.) So you can get the realest kind of moving pictures by simply bringing in the caterpillars that are easily found in garden, field, and wood. To collect these caterpillars it is only necessary to be provided with a pair of sharp eyes and an empty coffee can or some other form of tin box. Go out into the garden or along the borders of the woods. Look carefully. If you see places where leaves have been eaten, search the leaves near by and you are likely to find one or more of the cater- pillars that caused the injury. Transfer them to the box and take them home with a few leaves of the food plant. There place them in some form of vivarium, which simply means a box or cage in which you can keep living creatures. The most satisfactory cages for rearing caterpillars are those which are open above so that there is not even a glass plate between the observer and the insect. This kind of vivarium is easily made by using a band of some sticky substance like the tree tanglefoot with which trees are commonly banded, or a strip of sticky fly paper. Any wide shallow box may be used by simply placing an inch- wide band of the sticky material around the vertical sides INTRODUCTION 45 near the top. The caterpillars will be free to move all over the open box but they cannot cross the band to escape. Fresh leaves are easily placed in the open box and the withered ones removed. The same plan may be adopted with wide glass jars, like the ordinary battery jar. Choose a rather large one and smear the inner side near the top with a band of sticky ma- terial. The caterpillars are thus prevented from crawling out, but they are open to observation at ^all times. {See plate, pages 1^8-1^9.) In the case of the caterpillars that change to butterflies no soil need be placed in the bottom of the jar as these will attach their chrysahds to the sides or to a stick or board which may easily be put in. In the case of many cater- pillars that change to moths, however, it is desirable to place about two inches of soil in the bottom of the jar. Then if the caterpillars are not cocoon spinners they can burrow into the soil when they are ready to change to pupae. Instead of applying the sticky material directly to the glass a strip of sticky fly paper may be glued to it. As a rule the buttei-fly caterpillar easiest to find lives upon cabbages. Go into the garden and you are likely to see a dozen green caterpillars upon as many cabbage plants. Bring in several of the larger ones and place them in a vivarium with some fresh cabbage leaves. In a few days some of them will be likely to fasten themselves to the vertical sides of the vivarium and shed the caterpillar skin. Each thus becomes a chrysalis. About ten days later this chrysalis skin will break open and a white Cabbage butterfly will come out. So your caterpillar goes through the four different 46 BUTTERFLIES stages of insect life. It was first an egg laid upon the leaf by a butterfly; the egg hatched into the caterpillar or larva; the larva changed to the chrysalis; the chrysalis changed to the butterfly or adult insect. One of the most satisfactory ways to rear the caterpillars of butterflies is to get the females to lay their eggs upon the food plant. In the case of many species this is not diffi- cult. The simplest way is to enclose the mother butterfly in a small gauze bag tied over the branch of the food plant. If she has eggs ready to deposit she is very likely to lay them under these conditions. After they are laid the mother butterfly may be allowed to escape, but it is well to replace the gauze protection as a safeguard against many sorts of enemies which may destroy the eggs or the young caterpillars that hatch from them. Another way is to enclose the butterflies with a twig of the food plant in a glass jar, sealing it tight to prevent the leaves from wilt- ing. The butterfly is likely after she has quieted down to lay her eggs upon the leaves. According to William G. Wright, who speaks from his long experience with the but- terflies of the West Coast, these genera will lay their eggs on anything: Parnassius, Argynnis, Euptoieta, Neonympha, and all members of the family Satyridae. In these cases one can get the eggs by simply enclosing the butterflies in glass jars or gauze nets without even the leaves of the food plant. William H. Edwards found in his long ex- perience that one can get the eggs of practically all butter- flies in confinement, provided only the insects are suf- ficiently mature so that the eggs are ready to be laid. He found that the cause of failure to get eggs from many of the Fritillaries early in the season was that the eggs were not matm-e and that from the same kinds of butterflies with INTRODUCTION 47 which he failed early in the summer he got plenty of eggs in September. There is here a rich field for observation and experiment for every natm-alist who wishes to take up the study of butterflies. He can be sure of the parentage of the cater- pillars and can trace them from the very moment of egg- laying through all their wonderful changes until they be- come butterflies again. Photographing Butterflies There is a famous old saying that to make hare stew it is first necessary to catch your hare. So if one wishes to make perfect pictures of butterflies it is first necessary to get the caterpillars. For though caterpillars are not butterflies they are butterflies in the making and they will show you most interesting stages in nature's manufacture of these dainty and exquisite creatures. Tliis is not, how- ever, the chief reason why the photographer should get them. He will wish to make perfect pictures and in order to do this he must have not only perfect specimens but living butterflies which are willing to look pleasant while he makes comparatively long exposures under conditions of light that he can control. If you catch a butterfly out- doors and bring it in you will be likely to find that it is by no means a docile subject. The sunlight shining through the nearest window will be a call which you cannot counter- act and your butterfly will constantly respond to it in a most vexing manner. So you must catch the butterfly young and take advantage of a brief but docile period in their lives when they are willing to pose before your camera in quite a remarkable manner. This is the period just 48 BUTTERFLIES after the butterfly emerges from the chrysalis when its wings are fully developed but before the tissues have hardened and the muscles in the thorax are strong enough for flight. At this time the butterfly is perfect, every scale is in its place and every spot of color is at its best, and it will rest quietly upon a flower, leaf, or twig while you adjust the camera and expose the plate. From one such specimen one can get many pictures upon different flowers and with different angles of view. {See plates, pages 160, 225.) In order to make admirable photographs of living butter- flies it is by no means necessary to have a regular photo- graphic studio. If one has a room lighted from the north or east one can arrange for exposure near the window, using cardboard reflectors to make the light more even from both sides. In such a situation one soon learns the exposure periods required and can easily get many beauti- ful photographs. A collection of prints of the butterflies of one's locality would be one of th« most interesting photographic exhibits that an amateur could select. It is comparatively easy to get rather full sets showing the life-histories of several of our larger species and such sets are of course of especial in- terest. In the case of those caterpillars which make nests upon the food plant, like the Painted Beauty larva which remains for weeks feeding upon the leaves of the common wild everlasting, the taking of the pictures of the different stages is comparatively easy. One can keep the plant with the stem in water, and get the caterpillar to change to the chrysalis, and emerge as the butterfly, in the nest made from the flower heads and the upper leaves. From (I (Irdu-iiKj hy W . I. Ihccroft THE BLACK SWALLOWTAIL Caterpillar, clirysalis and Initterfly Src p(i(J(' ■'>'■> 'I'wD liiinilriMl Mniiarclis rcsliiiu on one driid liiiih 4 i'lf ^ ^yi w^: W^Mim^^ KiPi::-^'"- ^ Pli()lflf/r(ij)li('(l 1)1/ Cnt'nj .S. Thomas Sec pp. IH. 2-1') "When a stick was thrown into the tree the air was ftill of Monarchs" A MIGRATION OF MONARCH lUTTTERFLIES Sri' i)(i(/r 'i-'i 'UK IMPUOVKl) OI'KX \IVAHirM From a photograph from lije by A. H. Verrill. See page U THE CYNTHIA MOTH AND THE COCOON FROM WHICH IT CAME INTRODUCTION 49 Butterfly Collections There are few groups in Nature which offer such ad- vantages to the collector as that of the butterflies. They are easily obtained, easily preserved, and retain their beauty for a long period even under exposure to strong light. They offer opportunities for serious study in which one cannot only review the facts which others have already discovered, but also hope to contribute something of value to the sum of human knowledge. The mistake most commonly made by beginners with butterflies, as with other coUections, is to undertake too much. Instead of starting on the hopeless task of making a collection of the butterflies of the world, it is much better to start with the intention of making a collection of those of one's own town. In the latter case one can hope soon to attain the desired end and then, if one wishes, it is a simple matter to reach out and make a collection of the butterflies of the state or even of the particular region in which the state is located. The natural limitations for a collection in New England is to make a collection of New England butterfhes. There is a splendid example of such a collection on exhibition in the museum of the Boston Society of Natural History. This contains representa- tives of practically every kind that has been collected in New England, and yet there are less than a hundred species in all. So it is apparent that a local collection should be attainable by any enthusiastic student and the very fact that the number of species is limited adds interest and satisfaction to the pursuit. The main value of any collection of objects lies in the 50 BUTTERFLIES point of view of the collector. The most natural point of view for a beginner is that of the local fauna, as indicated in the previous paragraph. Such a collection best serves as a basis for a study of the subject but it may well lead to a broader field through some special phase of scientific interest. Thus while it would be hopeless for most per- sons to attempt a collection of the butterflies of the world it would be entirely reasonable for one to start a collection of all the species in the world of any given genus or tribe, and such a set of specimens would soon come to possess decided scientific value. Or, instead of the point of view of generic or family relationship, one could take the point of view of special geographical distribution. Thus a collection of all the butterflies found within a certain number of degrees of the North Pole showing the circumpolar butterfly fauna would have great scientific interest. There are also various other points of view which could be followed in making a collection. There are already in many of the museums of the world collections of butter- flies which illustrate the various phases of true mimicry — the resemblance of one species to another in the same re- gion. This is a field in which one could spend a lifetime of endeavor, and secure results of great value to the world of science. An easier problem for most collectors in the United States would be a collection made from the point of view of resemblance to environment, including such examples as the Angle-wings that show a bark-like set of marks on the under surface. Yet another point of view would be that of hibernation, the making of a collection of all butterflies that hibernate as adults. These are only a few suggestions. There are many INTRODUCTION 51 other phases of butterfly life which could be utilized as the basis for interesting collections. The important thing is to have a definite object in view and to make the collection a basis for a real study of the subject, so that the collector will not only be growing intellectually but will also be making a real contribution to our scientific knowledge. Collecting Apparatus To collect and preserve butterflies in proper condition for study, certain apparatus is necessary. Perhaps the first essential is the collecting net for catching butterflies in the field. The simplest way to obtain this is to buy it of the dealers in entomological supplies. Nets in con- siderable variety and at various prices are offered in the catalogues of these firms. One can make, however, a net at home with httle difficulty. One need only obtain an iron wire about one fifth of an inch in diameter and bend it into a circular ring a foot or fifteen inches wide, leaving the ends projecting at right angles to the circle and hav- ing a blacksmith weld them together so as to form a spur about four inches long. Now thrust this spur into some convenient handle, such as a broomstick, and sew over the wire circle a bag of mosquito netting, Swiss muslin, or some similar fabric. It is better that this material be green or black rather than white. After the butterflies are caught, they must be killed, so some form of killing bottle is necessary. Most collec- tors use a cyanide bottle, in which the fumes of cyanide of potassium kill the insects. One of the best ways to make this is to place in a wide-mouthed bottle two or three lumps of cyanide of potassium, approximately an inch across. Over this place some fine sawdust and on top of 52 BUTTERFLIES the sawdust, pour liquid plaster of paris carefully so that it will harden into a layer about half an inch thick. Allow the plaster to become thoroughly dry, then insert the stopper into the bottle and it will be ready for use. It is better to use a ground glass stopper so that the bot- Butterfly Envelopes. Fold first on line AB; then on AD and CB; then on BF and EA. (From Holland) tie will always be air tight. The sawdust is often omitted, the plaster of paris being poured directly over the cyanide. The special advantage of the sawdust is that it tends to absorb the cyanide in case it liquefies, as it often does in damp weather. As this cyanide is a deadly poison, it is better to let a druggist prepare the bottle or else to buy it already pre- pared of the dealers in such supplies. After the specimens have been killed in the cyanide bottle, some method of keeping them is necessary. The simplest way is to pre- serve them with their wings closed together in pieces of paper folded over into triangles as indicated on the Setting Board with Butterfly in place. (From Holland) INTRODUCTION 53 accompanying diagrams. Such specimens may be kept for an indefinite time and if one wishes to mount them later, it is only necessary to place them for a few hours in a relaxing jar, which is simply a closed ves- sel with enough water in the bottom to saturate the air with moisture. A great advantage of keeping the specimens in these paper covers is that they require so little room and are easily stored away in tin cans or boxes where they are safe from dust and destroying enemies. Those butterflies which are to be preserved in the ordi- nary way, in drawers or cabinets, must be spread out and held in position while the body is drying so that the wings will remain expanded. For this pm-pose, some form of a setting board is necessary. These may be bought of deal- ers or made at home. One of the simplest kinds consists of two thin strips of pine board, a foot or more long, nailed to end pieces with a space between the two boards wide enough to accommodate the bodies of the butter- flies. Beneath this open space, a piece of thin cork is tacked. The pin on which the butterfly is fastened is pushed through the cork until the wings of the insect are level with the boards. The wings are then brought forward with a needle point until they are in the desired position and they are then held in place by pieces of glass or by bits of cardboard fastened down by pins. The butterflies must be left in this position until thoroughly dry. Special insect pins should be used for butterflies. These are longer than common pins and have rounded heads. They are offered for sale by entomological deal- ers. Instead of pinning the insects and preserving them 54 BUTTERFLIES in cabinets, one may keep them in the Riker mounts, which have the advantage of being sealed so that there is no chance for dust or museum pests to reach the speci- mens. If one wishes to collect extensively, one will need Drying Box for Setting Boards. (After Riley) a considerable number of setting boards and it will be worth while to prepare for them a special drying box like that shown in the picture above. PART II THE TRUE BUTTERFLIES SuPERFAMiLY PapUionoidea The great suborder of butterflies is commonly sepa- rated into two principal groups called superfamilies. One of these includes all of the higher butterflies and is named Papilionoidea. The other includes the lower Skipper butterflies and is named the Hesperioidea. The former are characterized by small bodies and relatively large wings, straight clubbed antennae, and the fact that the caterpillars do not make cocoons when preparing for the chrysalis state. The most authoritative classifications of butterfly families are based upon the peculiarities of wing venation and are admirably discussed in such books as Holland's "Butterfly Book" and Comstock's "How to Know the Butterflies." Without attempting to go into the tech- nical details of structure it will suffice here to give the list of families which compose the superfamily Papilionoidea: The Parnassians. Parnassiidae. The Swallowtails. Papilionidae. The Whites, Orange-tips, and Yellows. Pieridae. The Nymphs. Nymphalidae. The Satyrs or Meadow-browns. Agapetidae. The Heliconians. Heliconidae. The Milkweed Butterflies. Lymnadidae. 55 56 BUTTERFLIES The Long-beaks. Lihytheidae. The Metal-marks. Riodinidae. The Gossamer-wings. Lycaenidae. It must not be thought that such a list necessarily indi- cates the degrees of development of the respective families, for this is not true. It is simply a linear arrangement adopted for convenience by leading authorities, notably Dr. Harrison G. Dyar in his standard "Catalog of Ameri- can Lepidoptera." THE PARNASSIAN BUTTERFLIES Family Parnassiidae It is perhaps a bit unfortunate that the group of but- terflies, which is commonly chosen to head the list of families, is one that is rarely seen by most collectors. The Parnassians are butterflies of the far north or of high ele- vations in the mountains. The four species credited to North America have been collected in Alaska and the higher elevations of the Rocky Mountains, so there is very little probability of any of them being found in the Eastern states. While, structurally, these butterflies have a close affin- ity with the Swallowtails, one would never suspect it from their general appearance. Their bodies are large and all of the wings well rounded, so that there is more of the suggestion of a large moth than of the Swallowtail. The coloring is also more moth-like than with most but- terflies, the wings being very light colored and nearly transparent, with markings of gray and brown, arranged in dots and splashes. THE SWALLOWTAILS 57 All our species belong to the genus Parnassius. The caterpillars show their affinity with those of the Swallow- tails by having the curious scent organs or osmateria just back of the head. They feed upon such alpine plants as stonecrop and saxifrage and are well adapted by their structure and habits to the bleak surroundings of the mountain tops. As a typical example of the environment in which these butterflies live, we may take the alpine valleys of such mountain regions as Pike's Peak. Prof. M. J. Elrod has described a visit where, at an altitude of 11,500 feet in the month of August, Parnassius smintheus was flying by thousands, and the earlier stages were so abundant that a water ditch had the surface covered as far as one could see with the dead or dying caterpillars. In such situa- tions, where ice forms at night, and snow frequently falls by day, these butterflies develop apparently in greater numbers than almost any of our other species are known to do in warmer regions. THE SWALLOWTAILS Family Papilionidae This is probably the most distinctive family of all our familiar butterffies. Its members are characterized by being on the whole the largest butterflies in our region and by having the hind wings prolonged into curious tail-like projections, suggestive of those of a swallow. In general, the basal color of the wings is blackish though this is com- monly marked in various striking ways with yellow, green, or blue, while the margins of the wings are commonly 58 BUTTERFLIES adorned with red or orange spots. These butterflies are also characterized by certain pecuharities in the brandling of the wing veins which will be found pictured in more technical works. The caterpillars of these butterflies have the character- istic form pictured on the plate of the Swallowtails op- posite page 80. When full grown they are large, fairly smooth-bodied worms, showing at most on the surface sparse fine hairs or fleshy threadlike projections. Their most characteristic feature is found in the scent organs called osmateria situated in the back just behind the head. These are thrust out, generally, when the caterpillar is disturbed and appear as orange Y- or V-shaped organs from which an offensive odor is commonly given off. They are supposed to serve the purpose of preventing in- jury by enemies, possibly birds, monkeys, and other vertebrates. Structurally, they are like long tubular pockets that can be turned inside out. When the pocket is in place it is getting a pocketful of odors. When it is in- verted it lets these odors free. On this account Professor Comstock has aptly called these caterpillars "the polecats of the insect world." When ready to pupate, these Papilio caterpillars spin a web of silk upon some more or less flattened surface and a loop of silk near by. They entangle their hind legs in the former and keep their heads through the latter so the loop supports the body a little behind the head. Then they change to chrysalids which are held in place by these sets of silken threads. The chrysalids are rather large and angular and gen- erally take on colors approximating their surroundings. They vary so much in different species that one familiar THE SWALLOWTAILS 59 with them can recognize the chrysalis and know the kind of butterfly it will produce. The Black Swallowtail Papilio polyxenes While the Black Swallowtail is not so large as some other members of the group, it is probably the best known to most people. It is found throughout many months of the year in practically all parts of North America south of Canada, and has the habit of flying freely about fields and gardens in search of flowers from which to suck its nectar food, and of plants on which to deposit its eggs. The fe- male butterflies have a remarkable abihty in selecting only members of the great family Umbelliferae for this purpose. In consequence the caterpillars are generally to be found feeding upon carrots, parsnips, parsley, and various wild spe- cies belonging to this order. (See plates, pages 48 and 6J^-65.) The eggs of the Black Swallowtail are laid one in a place upon the leaves of the food plant. Each egg is a small, yellowish, smooth, and ovoid object. It may often be found by watching the butterflies as they fly low in search of umbelliferous plants, and seeing one stop for a minute or so while she lays the egg. About ten days after the egg is laid it hatches into a small black caterpillar marked in a characteristicjfashion with a blotch of wliite in the middle of the body which is suggestive of a saddle. The caterpillar immediately be- gins to feed upon the green substance of the leaf, continu- ing thus about a week before the first moult. At this time it does not change much in appearance, still being a 60 BUTTERFLIES spiny creature blackish in color and marked by the curious white saddle. A little later it moults again, retaining its original coloring. At each moult, of course, it gets larger and feeds moie freely upon the celery or other plant on which it may happen to be. When the caterpillar becomes about half grown it takes on a very different appearance from that of its early life. The skin is smooth rather than spiny, and the general colors are green, black, and yellow. The ground color of the skin is green, which is marked with black cross- bands along the middle of each body ring. On these bands there are many large dots of orange yellow, the whole coloring giving the insect a very striking appear- ance, especially when it is placed by itself against a plain background. When they finally become full grown in this larva state, these caterpillars are almost two inches long. The larvae of the Black Swallowtail have certain char- acteristics in which they differ from many other cater- pillars. After each moult they do not devour their cast skins, which happens in the case of many of their relatives. When feeding, as well as when resting, they remain ex- posed upon the leaf and seem never to attempt to conceal themselves, as is the habit with a large proportion of cater- pillars. It is probable that this instinct for remaining ex- posed to view bears some relation to the curious means of protection possessed by this as well as other Swallowtail caterpillars. When disturbed one of these larvae will push out from just back of the head the strange-looking, orange- yellow Y-shaped organ which gives off a very disagreeable odor. These osmateria organs are generally believed to be defensive against the attack of birds and various other THE SWALLOWTAILS 61 enemies, although they seem not to be effective against in- sect parasites. The full-grown caterpillars are likely to leave their food plants when ready to change to the chrysalis state. They wander in various directions until suitable shelter is found. A piece of board, a fence post, or possibly the bark of a tree will answer for this purpose. Here the caterpillar spins a mat of silk in which to entangle its hind legs and a short distance away near the front end of the body it spins a loop of silk attaching the ends to the support. These serve to hold the chrysalis in place during this help- less period. After the loop is made the caterpillar keeps its head through it so that the loop holds the insect in po- sition a short distance back of the head. It is now ready to moult its last caterpillar skin and become a chrysalis. One who has watched hundreds of these caterpillars go through this change. Miss Mary C. Dickerson, describes the process in these words: "In this final moult the chrys- alis has to work very hard. The bulk of the body is again slipped forward in the loosened caterpillar skin, so that this becomes tensely stretched over the anterior end, and very much wrinkled at the posterior end. The skin splits back of the head and is forced back by its own taut condition and by the efforts of the chrysalis, until only the extreme posterior end of the chrysalis is within it. Then the chrysalis withdraws this posterior end with its many very tiny hooks, from the skin on the dorsal side, and, reaching around, securely fastens the hooks into the button of silk. Then the old skin is removed both from its fasten- ing to the chrysalis and from its attachment in the button of silk." A short time after the caterpillar's skin has thus been 62 BUTTERFLIES cast off the chrysalis takes on a brownish color which as is so often the case is likely to vary somewhat according to the tint of the surrounding surfaces. This is doubtless a protective device and helps the insect to escape attack by birds during the long period of exposure. For this butter- fly passes through the winter only in the chrysahs con- dition, and the larva which went into the chrysalis in September does not come out as a butterfly until the fol- lowing May or June. There are, however, two broods of the butterflies in the North and at least three in the South. As the adults live for about two months and there is con- siderable variation in the periods of their development it happens that one can find these Black Swallowtail butter- flies upon the wing almost any time in warm weather, either North or South. The Giant Swallowtail Papilio thoas The largest of our North American butterflies is a mag- nificent insect with a wing expanse of some four inches and with a rich coloring of black and yellow more or less suf- fused with greenish or bluish iridescence that gives it a striking beauty as it flies leisurely about from flower to flower or stops to lay an egg upon some bush or tree. The tails are long and expanded toward the tip, their prevailing color being black with a broad splash of yellow near the end. In a general way we may say that the upper wing surface is black marked with two bands of orange-yellow, while the under surface is yellow marked with two bands of black. {See jplate^ page 64-.) THE SWALLOWTAILS 63 The Giant Swallowtail is a tropical species which is abundant throughout the Southern states and during re- cent years seems to have been gradually extending its northern range. It is now commonly found as far north as forty- two degrees latitude, from Nebraska eastward. In New England it is occasionally taken in Connecticut, Massachusetts, and even in Maine, but its appearance in this region is exceptional. In the orange-growing regions of the Southern states the caterpillars of this butterfly feed freely upon the leaves of citrus fruits and they are often called "orange puppies" or "orange dogs." Probably their curious appearance and their habit of resting for long periods upon leaf or twig gave rise to this name. In the region indicated the life- history of the insect may be summarized thus: The mother butterfly deposits the eggs singly upon the young growth of orange or other citrus fruit trees, generally near the tips of leaves or branches. About a week later each egg hatches into a caterpillar that feeds upon the young leaves, resting upon the lower surface when not eat- ing. After a few days of this feeding the caterpillar be- comes too large for the skin with which it was born and it moults, coming forth with a new skin which soon hardens so that it can begin feeding again. A week or so later it moults for the second time, and continues these processes of feeding and moulting until full grown, which is perhaps a month from the time of hatching from the egg. At first the caterpillars eat only the succulent young leaves and branches, but as they grow larger they feed more freely upon the older foliage. They are very voracious and when abundant may often do much damage especially to young trees. When ready to change to the chrysalis each cater- 64 BUTTERFLIES pillar attaches itself by silken threads to the bark of the trunk or branch of the tree. Here it changes to a chrysalis which takes on a color so similar to that of the bark that the insect is surprisingly difficult to discover. A fort- night or so later it changes again into a fully developed butterfly that sallies forth in search of the nectar of flowers. {See plates, pages 67 and 24-0.) These "orange dogs," like the caterpillars of other Swal- lowtail butterflies, have curious yellow scent organs which, when the caterpillar is disturbed, protrude from the upper surface just behind the head. These give forth a very dis- agreeable odor which is believed to serve the purpose of re- pelling birds and possibly other enemies. It has been noticed that these caterpillars are not molested by birds al- though they are attacked by various insect enemies. Each mother butterfly is known to be able to deposit four or five hundred eggs and it has been suggested that the injuries of the caterpillars may be checked by shooting the butterfly upon the wing with cartridges loaded with small bird shot. In the South there are several broods in a season. The life-history of this species in more northern regions differs in the choice of the food plant and the number of broods. It feeds upon various members of the rue family, including common rue and prickly ash, as well as upon certain poplars and probably other trees. It is two brooded and apparently winters as a chrysalis. The but- terflies of the first brood come from the chrysalis about the last of May and are found on the wing during June. Those of the second brood come from the chrysalis about the last of July and are found on the wing during August and Sep- tember. The length of time required from the laying of the egg to the emergence of the butterfly varies greatly with From a drairing hi/ Mart/ E. Walker See page 62 GIANT SWALLOWTAILS Msitiiif,' blossuining brandies of tlie orange In'i-. (Reduced) Sec page .'>'.) BLACK SWALLOWTAIL VISITING THISTLE, SHOWING THE TONGUE PARTIALLY UNCOILED J'ltoloi/riijilicd J'ruiti lij'c IMPORTED CABBAGE BUTTERFLY (\ li'ood (l(Nil magnified) Src pagt; 80 See page 65 THE BLUE SWALLOWTAIL Upper surface above; lower surface below THE SWALLOWTAILS 65 the locality and the temperature. It commonly extends over a period of four or five weeks. The Blue Swallowtail Laertias philenor The Blue Swallowtail is said to have closer affinity with the splendid butterflies of the tropics than most of our other Papilios. The sheen of metallic color upon its wings is certainly suggestive of the broad expanse of similar color- ings in the gorgeous butterflies from South America. This species is easily recognized by the general blackness of the front wings and the basal parts of the hind ones as seen from above, about two thirds of the area of the latter being overlaid with blue-green scales that give the metallic lustre characteristic of the species. Near the outer border of the basal half of the front wings there is a row of about five rather indistinct whitish spots, this row being continued more distinctly on the hind wings. On the under surface the white spots of the front wings are more pronounced than on the upper, while each hind wing is brilliantly marked with about seven large orange spots, part of them fringed on one or both sides with a distinct margin of white. The extreme side borders of all four wings are distinctly marked with white crescents and the fringes on the tails as well as more or less of the darker fringes of the hind wings are of a beautiful purple color. In the males each hind wing has along the inner border a slender, pocket- like depression which is said to be the seat of the scent organs. (See plate, page 65.) This splendid butterfly is a southern species. It is 66 BUTTERFLIES found from the Carolinas to California, being at times ex- tremely abundant in certain localities over this great region. It seldom occurs as far north as New England and in a general way east of the Rocky Mountains its northern limit approximates that of forty-three degrees of latitude. It varies considerably in size and differs greatly in abundance in different localities and different seasons. Probably the commonest food plant of the caterpillars is the Dutchman's Pipe or Aristolochia, which is fre- Caterpillar of the Blue Swallowtail. (After Riley) quently planted as an ornamental vine for porch aaorn- ment. It also feeds upon wild ginger or Asarum and probably upon other plants. A dozen or more eggs are laid upon a leaf by the mother butterfly, usually in a clus- ter or grouped near together. They hatch a week or so later into small brownish caterpillars which remain to- gether for awhile in little groups that feed side by side upon the leaf, beginning at the margin and working toward the centre. As they become larger they feed more freely and gradually disperse so that each forages for himself. As they approach maturity their appetites become vora- cious and their presence is often shown by the defoliated condition of the branches. They have back of the head the osmateria or scent organs which are commonly found TWO OF THE SWALLOWTAILS (Three fourths natural size) The Palauiedes {see page 76) The Giant {■tee page 6,2) Scr j)(l(/r I'l THE GREEN-CLOUDED SWALLOWTAIL tTppor surface alxivc; Imvcr surface l>el(>\v THE SWALLOWTAILS 67 in the other caterpillars of this genus, but the odor emitted by them is likely to be less pronounced than usual. When full grown the caterpillars find such shelter as they may and each spins a bit of silken web and a silken loop which hold it while it changes to the chrysalis. This chrysalis is very likely to take on the colors of the immedi- ate surroundings and thus be rather difficult to see. If the egg was laid by one of the spring or early summer butter- flies, the chrysalis will soon change to a butterfly which will appear toward midsummer and which may lay eggs for another brood of caterpillars. These caterpillars mature to chrysaUds the same season and some of them are believed to change into butterflies in autumn, these butterflies hibernating through the winter; while others are believed to remain unchanged through the winter and disclose the butterfly the following spring. This is an exceptional condition for the Swallowtails and it is worth while to make careful observations along its northern limits to learn more definitely the facts as to the winter condition. The Green-clouded Swallowtail Papilio troilus This beautiful butterfly is essentially a southern species and is found over a wide range of territory from the Mis- sissippi River to the Atlantic Ocean. It occurs as far north as New Hampshire and Vermont and has even been re- ported from Alberta, Canada. It is easily recognized by the blue-green clouding of the upper surface of the wings, the general color being velvety black with distinctive 68 BUTTERFLIES rows of yellow spots along the margins of the front wing. These spots are present also on the hind wing where they are almost changed to blue because overlaid with a gen- eral cloudiness of this color. On the under surface of the hind wings there are two rows of orange-brown spots, the inner row being nearly crescent-shaped and the outer row oblong. In the living insect the tail projections on the hind wings are usually twisted into a vertical plane at right angles to the plane of the wings. {See plate, page 67.) The caterpillars of this species feed upon the leaves of sassafras and spice bush. The distribution of the but- terfly appears to be closely related to the distribution of these plants. As is the case with so many of our Swallowtail butter- flies, the Green-clouded Swallowtail passes through the winter in the chrysalis stage. Late in spring the butter- flies emerge and soon afterward lay their eggs singly upon the leaves of sassafras or spice bush. The eggs soon hatch into lead-colored caterpillars, largely covered with spiny warts. Each caterpillar cleverly makes a protecting nest by eating out a narrow strip in the leaf which frees a flap along the margin that is turned back upon the leaf, making a case in which the larva lives. It spins a silken carpet on one side of the case and rests upon this car- pet when at home. During its feeding periods it goes outside and eats the tissues of the other parts of the same leaf. It continues to occupy this first nest for a week or more by which time the rest of the leaf is likely to be pretty well consumed. Having passed the first moult and thus become larger and having practically eaten itself out of its first house and home the caterpillar now crawls to a larger leaf where THE SWALLOWTAH^S 69 it proceeds to make a more enduring structure. In this case it does not need to bite a channel along one side of the midrib as it did before, but instead it begins to spin silken threads transversely across the upper surface in such a way as to fold over the border of the leaf and make a tubular chamber in which it has plenty of room to move about. It uses this as its home for some time thereafter, wander- ing out at evening to feed upon neighboring leaves as its hunger necessitates. In this way it continues to feed and grow for a week or two. Then it finds it necessary to construct still another home, which it does by bringing together the opposite sides of a leaf, taking care to have a door-like opening at the base of the blade next the leaf stalk. This third home serves it to the end of its larval existence. It goes in and out as necessary, remaining con- cealed when it casts its skin and until the body tissues harden afterward. Apparently it devours the cast skin and thrusts the hard covering of the head out of the nest. Consequently these little homes are clean and sanitary and serve admirably their protecting purpose. The full-grown caterpillars have the curious appearance of those of the other Swallowtails. The third ring behind the head is greatly swollen, making, with the rings di- rectly in front of it, a characteristic picture suggesting a grotesque face with large eye-like spots at the top. The general color is green, darker above than below, and there are six rows of blue dots along the body. {See plate, page 80.) When ready to change to the chrysalis, the caterpillars desert their leafy homes and on a twig or board or stone each spins a bit of silken webbing and a silken loop. They now change to chrysalids which are likely to resemble the color of the background and which are somewhat smoother 70 BUTTERFLIES than many of the Swallowtail chrysalids. About two weeks later the butterflies emerge. The Eclosion of the Butterfly The transformation of a chrysalis into a butterfly is always one of extraordinary interest. Comparatively few definite descriptions of this process have been given by careful observers. One of the best of these is that written by Mr. Scudder in connection with the emergence of this butterfly, and it is so accurate and complete that it seems worth while to quote it at length: "The butterfly generally emerges from the chrysalis early in the day," writes Mr. Scudder, "and the first signs of the immediate change are strong forward and back- ward movements of the chrysalis at intervals of a few seconds; perhaps the third or fourth attempt will be suc- cessful, when a click may be heard at the distance of several feet; but all the subsequent movements are abso- lutely noiseless, though rapid; at intervals of three or four seconds, spasmodic movements similar to the first carry on the process; first the split continues along the thorax; then it runs down either side between the legs and wings, ultimately to the tips of the antennae. As this progresses, the actions become more strenuous and more frequently repeated; with eager efforts the butterfly pushes forward its half -detached head; now an antenna springs from its case, at once assuming its natural attitude; the other soon follows, and then the wings are partially drawn from their sheaths, and while in this position seem to be used as levers or arms to aid in withdrawing the rest of the body; next the legs appear, seize the upper part of the chrysalis skin, and speedily withdraw the whole body. It is now a THE SWALLOWTAILS 71 curious-looking object, the wings wrinkled and bloated, and, although the whole process of escape lasts little more than half a minute, already twice the size of the sheaths they lately occupied. The insect crawls upward until it finds a secure resting place, and there remains until ready for flight; each half of the tongue, drawn independently from its receptacle, is rolled in a separate spiral, and now while the wings are gradually expanding the insect applies all its energies to uniting their two parts, incessantly rolls and unrolls them, and beginning simultaneously at the base, gradually fits them together by their interlocking joints; in about fifteen minutes all but the tips are per- fectly united; these require nearly fifteen minutes more, and are not fairly interlocked until the wings are fully expanded, nearly a full half hour after the escape from the chrysalis; the wings, however, are still tender, and gener- ally require two hours to stiffen. When at last the insect ventures upon flight, it is not with an uncertain flutter, but boldly and steadily, as if long accustomed to the action." The butterflies of this second brood of the season are likely to begin to appear early in August, continuing to be- come more abundant throughout that month. These lay eggs upon the same food plant and the caterpillars grow to maturity in the same way as those of the first brood. They become full grown during September or October, and then change to chrysalids which remain dormant until the following spring. The species thus has two broods each year and passes the winter only in the chrys- alis state. These beautiful butterflies are likely to be found in the sort of situations where the food plants of the larvae are 72 BUTTERFLIES growing. Open groves, the borders of woods, and the margins of streams or marshes are the places where one is most likely to find spice bush and sassafras. These are the places to look for these butterflies which one may often see in graceful flight near the ground, pausing now and then to seek a sassafras leaf or to sip the nectar from a flower. The Tiger Swallowtail Papilio glaucus One of the many things that make a study of the life- histories of butterflies of great interest is the variations in the development of many of the species. One who follows the simplest life-story of a butterfly and sees the egg change to larva and the larva change in size and form and color with each successive moult and then change again into the seemingly inert chrysalis, from which there finally comes the winged butterfly — unlike the egg, unlike the larva, unlike the chrysalis — a creature of perfect beauty, wonderfully adapted to living freely in the air and sipping ambrosial nectar from the flowers — one who follows these changes with awakened vision can scarcely fail to have a sense of wonder as to the laws that govern such intricate phenomena. But the marvel is still more pronounced in the case of those butterflies which have two or more forms arising from the same lot of eggs in a way which science has as yet not adequately explained. The splendid Tiger Swallowtail is an example of this dimorphism which is of especial interest because of the fact that the extra form is confined to one sex and to only a part of the geographical area over which the butterfly is THE SWALLOWTAILS 73 found. The species occurs over a very large part of the North American continent, being found from ocean to ocean and from Canada to Florida. In the region north of approximately the fortieth degree of latitude there is but one form of the insect — the familiar yellow-and-black striped butterfly which every one has seen visiting the hlac blossoms in May or June. South of this, however, part of the females take on an entirely different appearance, being almost wholly black with the hind wings touched with Hues of blue and bordered with crescents of yellow and orange. The curious thing about it is that a certain mother butterfly may lay a dozen eggs part of which will develop into the usual yellow form and the rest into the black form, both lots being of the same sex. This black form is so entirely distinct in appearance that the two were originally described as separate species, and they were long considered such, until breeding experiments deter- mined the precise condition. (See plates , pages 17 and 96.) This species is of interest also for another reason. The caterpillars during their later life are remarkable examples of that curious resemblance to the head of a serpent which is thought to have a real protective value in frightening away attacking birds and possibly other enemies. The rings of the body just back of the head are much swollen and on the top of the swollen part there are two large circular marks which bear a striking resemblance to eyes. When the insect is at rest it withdraws its head and holds up the front of the body in such a way as certainly to sug- gest at the first glance that one is looking at the head of a small snake, an impression which is likely to be enhanced when the caterpillar pushes out the curious yellow scent organs from the ring near the top of the head, these 74 BUTTERFLIES organs taking on the forked appearance of a snake*s tongue. Obviously it is exceedingly difficult to get definite ob- servations under natural conditions to determine whether these seeming resemblances are really of value to the cater- pillar in frightening away birds or other enemies. About the only direct evidence which I have come across upon this point is found in this paragraph by Dr. J. L. Hancock: "When I recall the first sight of this larva, the impres- sion gained of it was a most curious one. The forwg^rd mask-like face was remarkably startling. This mask, bearing eye-like spots and the light transverse ridge, gave it an aspect which might easily be mistaken for real eyes and a mouth. This contrivance is only a false face in no way connected with the real eyes and mouth. One might imagine the shock that a bird, or other predaceous enemy, would experience when looking upon this grinning mask. This is in reality the effect produced, for I have seen small birds so alarmed that they lost their appetite and curiosity for these larvae after a brief glance at them. It is certain that these singular markings have the effect of terrifying their bird enemies."* The yearly cycle of the Tiger Swallowtail is much Eke that of the related species. It passes the winter as a chrysahs, the butterflies coming forth just about the time that the lilacs bloom. They remain upon the wing for a few weeks and deposit theu: eggs upon a great variety of trees and shrubs, for the food plants of the larvae are tm- usually varied and include tulip trees, birches, wild cher- ries, apples, poplars, ash, and several other common trees or *"Nature Sketches in Temperate America," p. 146. THE SWALLOWTAILS 75 shrubs. These eggs soon hatch into caterpillars that feed upon the leaves and make for themselves resting places by spinning a web of silk transversely across the surface of the leaf. They remain upon these silken webs when not feed- ing and in later life are likely to cause the leaf on which the web is made to curl into a partial tube. When fully de- veloped they change to chrysalids which give forth the summer brood of butterflies in July and August. These in turn lay eggs for the caterpillars which change to chrysalids in autumn and remain in that condition until the following spring. The Short-tailed Papilio Papilio brevicauda Were one enough of a magician to make one butterfly over into another it would be comparatively easy to take a Black Swallowtail and transform it into this species. One would only need to trim off the long tails so that they project very slightly from the angles of the hind wings and to change the yellow spots to orange. He would thus accompHsh what Nature through the long ages seems to have accomplished in a limited northern area in New- foundland and around the Gulf of St. Lawrence, for the Short-tailed Papilio is confined chiefly to this region, where it lives a life very similar to that of the Black Swallowtail. The caterpillar feeds upon the leaves of various members of the parsley family and is said to have learned to warm itseK during the middle of the day by resting upon stones and gravel which have absorbed the sun's heat rays. Presumably there is but one brood a year and the insect hibernates as a chrysalis. 76 BUTTERFLIES The Palamedes Swallowtail Papilio palamedes If the magician who had succeeded in converting a Black Swallowtail into the Short-tailed Papilio wished to try his hand on making a Palamedes Swallowtail he could not do better than to use again the same black butterfly. He would only need to make it about one half larger, retaining practically all its color markings and the outline of its wings and tail. For this species bears a remarkable re- semblance to the Black Swallowtail, seeming to be a giant variety induced by the warmth of the southern chmate where it lives, and possibly by the more generous supply of the magnolia and sassafras leaves upon which the cater- pillars feed. {See plate, page 66.) This species is distinctly a southern form occurring as far west as the Mississippi River throughout the more Southern states. As one would expect in the long seasons and warm climate of this region there are several broods each year and the caterpillars often hibernate as well as the chrysalids. The adult butterflies are lovers of the sun and are said to roost at night upon the tops of hve oak and palmetto trees. The Zebra Swallowtail Iphiclides ajax Most of our Swallowtail butterflies are so distinctive in form and colors that they are easily distinguished from one another, but the Zebra species Is so different from all the THE SWALLOWTAILS 77 rest that when it is once seen it is Hkely always to be re- membered. The striking combination of green and black stripes with very long tails, set off by beautiful crescents of blue and of red, at once distinguishes this fine butterfly in any of its varying forms. (See plates, pages 112-113.) Three distinct forms of this species occur, namely: Marcellus, the early spring form, small in size with short tails, that show white only on the tips; Telamonides, the late spring form, somewhat larger, with tails a little longer and showing more white on the outer half; Ajax, the summer form, decidedly larger with tails very long. It would be a comparatively simple matter to under- stand these forms if they were simply seasonal variations, with three broods, each form succeeding the other as the season advances. But this is far from being the case. We have instead the most complicated and confusing series of conditions imaginable — conditions for which no one has yet given satisfactory explanations. To make a fairly clear statement of what happens, sup- pose we assume that we start with twenty over-wintering chrysalids. In April ten of these disclose their butterflies which are Marcellus, the early spring form. In May the other ten disclose their butterflies which are Telamonides, the late spring form. We thus have these two forms ap- pearing successively in spring from the same set of over- wintering chrysalids. After flying about for a short time the Marcellus or early spring Swallowtails lay eggs upon the leaves of pa- paw trees or bushes. These eggs soon hatch into cater- pillars that feed upon the leaves and grow rather rapidly. 78 BUTTERFLIES A little more than a month later they matm*e into butter- flies which are Ajax, the summer form. In a similar way the Telamonides or late spring butter- flies lay eggs soon after they appear, also upon papaw leaves, and these eggs in about a month mature into Ajax, the summer form. So we have Ajax, the summer form, developing directly from both the early spring or Marcellus and the late spring or Telamonides butterflies. These Ajax butterflies in their turn lay eggs for cater- pillar young. These soon mature into a brood of butter- flies which are of this same Ajax form. There may be successive broods through the summer, practically all of them being this same Ajax summer form. The last brood of caterpillars, however, change to chrysalids which do not disclose the butterflies until the following spring. And then the first that come out are the Marcellus form and the last the Telamonides form. So we may have these two forms maturing from the same brood of autumn caterpillars. This seems a sufficiently complicated life-history to suit the most persistent solver of puzzle problems, but there is an additional factor which adds much to the possible con- fusion of the broods. In each brood of caterpillars from the earliest to the latest there are a certain number of chrysalids which remain dormant through the remainder of the season and the following winter, maturing into butterflies the next spring. Consequently at the end of every winter there are a miscellaneous lot of chrysahds which represent every brood of caterpillars that lived the previous season, and all of these develop into either Mar- cellus or Telamonides butterflies. THE SWALLOWTAILS 79 Such a condition of affairs certainly represents what an old New Englander would be likely to call a "mixed-up mess," and it is difficult for science to find rhyme or reason to explain it. It speaks eloquently for the perseverance of W. H. Edwards that he was able with infinite patience through years of study and experiment to untangle this in- tricate web of butterfly existence. While the preferred food plant of this species is papaw, the caterpillars are also known to feed upon the spice bush and upland huckleberry. When full grown these cater- pillars are about two inches long and of a general pea-green color, banded transversely with yellow and black, and hav- ing an especially conspicuous band of this sort on the third ring behind the head. The scent organs are protruded when the larva is disturbed and emit an offensive odor. The chrysalids are green or brown according to the sur- roundings. The Zebra Swallowtail is a southern butterfly found as far west as Texas and the Rocky Mountains and having its northern limits in a zone ranging approximately from Massachusetts to Nebraska. It is especially abundant in the Southern states east of the Mississippi River. Mr. S. F. Denton found this species abundant in south- ern Ohio where the females laid their eggs upon the small papaw bushes. They selected the leaves of these bushes for sleeping quarters, "clinging to the under side of the leaves where early in the morning they might be taken with the fingers." Other Swallowtails Several other Swallowtail butterflies are found within the limits of the United States, especially in the Far West 80 BUTTERFLIES and along the southern boundaries. Some of these occa- sionally migrate east or north so that they are collected in the Central states. Thus Papilio daunus, P. oregonia, and P. zolicoan are aU found in the "List of Nebraska Butterflies," published by Mr. H. G. Barber, and the same species have been taken in other states in or near the Mississippi Valley. These and various others are described and pictured in Dr. Holland's excellent "Butterfly Book." Synopsis of the Swallowtails Tiger Swallowtail: Yellow form {Papilio glaucus turnus) . Expanse 3| to 5 inches. Upper surface of wings bright yellow with each black margin marked with a row of yellow spots. Both sexes throughout its range. Black form {Papilio glaucus glaucus) . Black all over with blue mark- ings on outer half of hind wings and row of straw-yellow crescents on borders of same. Females only, and only south of about latitude 40 degTces. Giant Swallowtail {Papilio thoas or Papilio cresphontes) . Expanse 4 to 5| inches. Upper surface black with two bands of yellow starting at the inner margin of the hind wings and coming together as a row of yellow spots at the outer angles of each front wing. A yellow spot on each black tail. Under surface yellow. Zehra Swallowtail. Expanse 3 to 3| inches. Easily known by the stripes of green upon black and the long, slender tails. The different forms vary in size and in the length of the tails. Scientific names are: Early Spring Form, Iphiclides ajax marcellus; Late Spring Form, 7. ajax telamonides; Summer Form, I. ajax ajax. Green-clouded Swallowtail {Papilio troilus). Expanse 3j to 4 inches. Black with about seven yellowish spots I- mm a photograph from life h>j A. II. I err ill See page, 7, 07 CATERPILLARS OF THE GREEX-CLOLDED SWALLOWTAIL In various stages of growth ^^ " 3|j \ \ \ \ I'l/dlof/rdjiliiil from life Sec JXH/c .V- i.MP()irri:i) cabbaci: bv 'nM-:HFi>y I'holitiiniplifil from lij'f 'Sec Jidi/r 'l- BM'K-KYKI) (;i{AYI>INO VISITIN'O .IOI<: PYK WKKD (Magnified) THE SWALLOWTAILS 81 on outer margin of each front wing and eight marginal spots on each hind wing, those at the ends of row orange, the rest yellowish or bluish. Outer half of hind wings clouded with greenish blue. Under surface black with two distinct rows of yellowish spots on front wings and two rows of orange spots on hind wings. Blue Swallowtail (Laertias philenor, often called Papilio philenor). Expanse about 4 inches. Black or brownish black with most of hind wings showing a bluish green ir- idescence. A row of marginal spots on each hind wing, more or less distinct on the front wings. Outer fringe with broad white markings interrupted by black ones. Under surface of each hind wing with seven large orange spots, some with partial borders of white. Black Swallowtail {Papilio polyxenes or Papilio asterias) . Expanse about 3 inches. Black with two conspicuous rows of yellow spots on outer half of wings, more dis- tinct in males. On hind wings rows of blue spots or splashes between the yellow ones. Orange-red circle with black centre at inner angle of each hind wing. Under surface with markings more distinct and more orange^ yellow. Short-tailed Sioallowtail {Papilio hrevicaudd) . Mucb like the Black Swallowtail but generally smaller, with very short tails, and with the yellow markings more or less changed to orange. Confined to the limited region of Newfoundland and the lands bordering the Gulf of the St. Lawrence. Palamedes Swallowtail {Papilio palamedes). Expanse 4 to 4| inches. Much like the Black Swallowtail but con- siderably larger. A curved yellow line on the head back of each eye. Found only in the South. 82 BUTTERFLIES THE WHITES, ORANGE-TIPS, AND YELLOWS Family Pieridae The most familiar and abundant American butterflies are classified together under the family name Pieridae, or the Pierids. Three groups or tribes of them are popu- larly known as the Whites, the Orange-tips, and the Yellows. Our two commonest butterflies, the White or Imported Cabbage Butterfly and the Sulphur Yellow Butterfly, are typical representatives of this family. Most of the rest, like these, are of moderate size with rounded wings which are more or less marked with black. There are six well-developed legs and the cater- pillars of practically all the species are cylindrical greenish worms which under a lens are seen to be covered with short hairs. When the caterpillars are ready to change to chrysalids they spin a web of silk upon the supporting surface and just back of it, a loop of silk that serves to hold the chrysalis in place and keep it from swaying back and forth. The chrysahds are characterized by having a pointed projection on the front of the head, the rest of the body being more or less angular. Notwithstanding their close general resemblance to their food plants, the caterpillars of this family suffer from attack by various enemies. Birds find many of them, not only eating them themselves but also using them freely for feeding the nestlings. Parasitic insects also take a heavy toll from these caterpillars. This attack of enemies is doubtless a chief reason why many of the common spe- cies are not much more destructive. THE TRIBE OF THE WHITES THE TRIBE OF THE WHITES Three white butterflies of approximately the same size are found widely distributed over the United States. The most abundant species is the White or Imported Cab- bage butterfly. The next in abundance is probably the Checkered White, and the rarest in most localities is the Gray -veined White which is a northern form. The White or Imported Cabbage Butterfly Pieris rapae There is probably no butterfly which one can generally find so easily in its early stages as the White or Imported Cabbage butterfly which is found practically wherever cabbages are grown and is generally so abundant that caterpillars and chrysalids are readily discovered. In the Northern states the insect passes through the winter within the chrysalis, coming forth rather early in spring as the familiar white butterfly with black dots upon the wings and blackish front angles of the fore wings. (See plates t pages 61^-65 and 81.) The butterflies that thus appear in spring flit freely about over fields, meadows, and gardens, sipping the nec- tar of various early flowers through their long, coiled tongues and stopping occasionally to alight upon the leaf of a cabbage or other plant of the mustard family to de- posit the small, pale yellow eggs which remain attached by a sort of glue. The adult butterflies continue their 84 BUTTERFLIES leisurely life for a fortnight or more, thus extending the laying of the eggs over a considerable period. About a week after being deposited the egg hatches into a tiny green caterpillar that begins feeding upon the ten- der surface of the cabbage leaf. It is commonly called the cabbage worm and it is doubtless the most generally destructive insect affecting this crop. It continues to feed for several days before the first moult, after which it becomes decidedly larger and begins to eat again more voraciously than before. It undergoes several successive moults during the next two or three weeks before it be- comes full grown as a caterpillar. Unlike most butterfly larvae it has changed very little in its general appear- ance during its growth. It is always of a pale green color, strikingly like the glaucous green of the cabbage leaf, a fact which doubtless helps to conceal it from the eager eyes of birds and other animals. When the caterpillar is thus full fed it is likely to leave its food plant and find shelter elsewhere. Sometimes it will stop on the lower surface of the outer leaves, but more commonly it will find a piece of board, an overhanging stone, a fence-post, or the side of a building, where it will prepare for the change to the chrysalis. It will do this by spinning a silken thread upon the surface in which to entangle its hind legs and a loop of silk near by with which to hold its body. When these preparations are com- pleted the insect will cast its last caterpillar skin, emerg- ing as a grayish or brownish chrysalis, the color usually varying with the color of the surrounding surface. The general shape of the chrysalis is shown in plate opposite page 97. A week or more later the chrysalis skin bursts open and THE TRIBE OF THE WHITES 85 the white butterfly emerges to expand and dry its wings before it flies away for its leisurely life. There are two or more broods each season, the number varying with the latitude. There is a decided variation in the length of time required for the completion of the cycle from egg to butterfly. In hot weather the insect may mature in about three weeks while in cooler weather it may require as much as five weeks. Its Introduction and Dispersal While it is well known that a large proportion of our most destructive insects have been imported from Europe, it is only in comparatively few cases that man has been able to make careful records of the times and places where the insects were introduced and to follow the spread of the pest from these original centres. The Imported Cabbage butterfly is one of the few species of which this is true. This insect has been known for centuries in Europe, where it feeds freely upon the leaves of cabbages and turnips. So far as known it was first introduced into North Amer- ica about 1860, when it appeared in Quebec. Eight years later it was again introduced into the region of New York City. From these two points the insect spread gradually in various directions until in 1871 it covered the whole of New England and various parts of New York and New Jersey. From then on it spread even more rapidly and was evidently accidentally introduced into various parts of the country which became new centres of distribution. Of course it would be very easy for this to happen through the shipment of cabbages from one part of the country to another. Within thirty years of the time of its first in- 86 BUTTERFLIES troduction it had become a serious pest over practically all the United States and Canada. The introduction and spread of such a pest is of inter- est in itself, but in this case there is to be noted the addi- tional fact that the presence of this foreigner has prac- tically led to the extinction of two native species of but- terflies, both closely related to each other and to the in- vader and both feeding upon the same plants. An almost pure white butterfly — the Gray-veined White — was form- erly exceedingly abundant in many of the Northern states, while farther south there was another species, the Check- ered White, which was also abundant. Both of these have now so completely disappeared that in some localities they are almost never seen, while their imported relative has become perhaps the most abundant of all American butterflies. The Gray-veined White Pieris napi One would naturally suppose that when a butterfly was reduced to the greatest possible simplicity in its color- ing there would be little chance for the development of geographical or seasonal varieties. But he would only have to study a large collection of specimens of this species > taken at different seasons and in different regions, to find his supposition at fault. Here is a butterfly which is essentially a slender black-bodied creature with four white wings scarcely touched with color, and yet we are told that there are eleven varieties in the United States so distinct that they have received scientific names, not to THE TRIBE OF THE WHITES 87 mention various others which have been found in Europe. This is indeed a remarkable showing and it is a striking illustration of the infinite variations which Nature can produce with the most limited materials. To me the seasonal variations of a butterfly are always of greater interest than those which are geographical. We know that in the case of a great many animals, from insects to mammals, the different conditions of climate and physical environment found in different regions pro- duce variations of many sorts. So it does not seem es- pecially strange that in Alaska there should be a different form of a certain butterfly than is found in Virginia. But that in the same locality there should be two or more forms of a butterfly existing under identical conditions as to climate and environment is not so easily explained. In the case of the Gray-veined White we collect in early spring in New England, or other Northern states, a lot of chrysalids. We keep them until the butterflies come forth and we find even here two distinct forms, one smaller and more delicate than the other, with both surfaces of the wings pure white : scientists call this form, virginiensis; the other larger with the under surface of the wings slightly tinted with yellow: scientists call this form oleracea. The first named has but one brood a year while the second lays eggs which develop into caterpillars that produce butterflies of still a third form, in which the upper surface of the wings is pure white with a slightly greater expanse: scientists call this form cruciferarum. These three varieties occur in Eastern regions and may be found in the same localities, and differ considerably from various geographical varieties found in the Far West. 88 BUTTERFLIES The caterpillar of the Gray-veined White is a bit smaller than those of the nearly related forms, and in color is green with no distinct longitudinal markings, but with many fine dots of black over the surface. The cylindrical body is covered with a fine down. When feeding upon cabbage it is more likely to attack the outer than the inner leaves, and so even when abundant it is less troublesome to gardeners than the imported species. It is now, how- ever, so rare that it seems to feed chiefly upon wild cruci- ferous plants and is more likely to be found along the borders of open woods than in gardens and fields. The winter is passed in the chrysalis state. The Checkered White Pontia protodice Some years ago the Checkered White was commonly called the Southern Cabbage Butterfly but the general distribution of the imported species has had the same ef- fect upon its abundance in the South that it has had upon the Gray-veined White in the North. Consequently, it is now much less abundant than formerly, even in the Southern states where it is most at home. There are two fairly distinct forms: the spring form and the summer form. The latter is practically of the same size as the Imported Cabbage Butterfly: the males have the hind wings nearly white above and the fore wings with a few black dots or spots upon their outer halves. The females are much more definitely marked, having the upper surface of both pairs of wings marked in black or brownish black in such a way as to enclose a large number of white diamonds. The THE TRIBE OF THE WHITES 89 spring form is decidedly smaller and the markings are much less distinct than in the summer form. The seasonal liistory of this species is comparatively simple. In winter the chrysalids are found. From these chrysalids in early spring the small butterflies of the spring form come forth. These lay eggs upon various crucifer- ous plants which hatch into greenish caterpillars that eat the leaves and soon mature so far as their caterpillar stage is concerned. They are then about an inch long, with downy cyhndric bodies more or less marked with rather pale yellow stripes, touched here and there with purplish green or dotted slightly with fine black dots. These cater- pillars now attach themselves by means of a button of silk and a silken loop to some support like a piece of board, the side of a stone, or almost any available shelter. Each casts its larval skin and appears as a grayish chrysalis from which probably a fortnight later the summer form of the butterfly emerges. There are commonly two broods of this summer form, making three sets of butter- flies for the entire season. The caterpillars of the second summer brood of butterflies go into the chrysalis stage in autumn to remain throughout the winter. Some very interesting observations upon the sleeping habits of this butterfly have been made in St. Louis by Mr. and Mrs. Phil Rau. The insects were found abund- antly resting upon the seed heads of white snakeroot. Early in October, when a warm south wind was blowing, the great majority of the butterflies slept horizontally with their heads toward the wind. At other seasons and in other places, many of them were found in a vertical position but practically all had their bodies toward the wind prevailing at the time. The observers were unable 90 BUTTERFLIES to ascertain definitely whether the insects thus oriented themselves at the time of alighting, so that their wings presented the least resistance to the force of the wind, or whether this was a mechanical result of the breezes. The Great Southern White Pontia monuste There used to be in the Northern states before the ad- vent of the Imported Cabbage butterfly a familiar white butterfly which then laid its eggs upon cabbages in much the same way that the imported pest now does. One who has seen this northern Gray-veined White and then sees the Great Southern White will be likely to think of the latter as a larger edition of the former, for in the males of the southern species the wings are practically white save for a narrow dusky border at the outer angle of the front pair, although in the female this dusky margin is wider and the hind wings show a series of dusky triangles near the margin. There is also a curious black marking suggestive of a crescent on each front wing near the middle of the front border, which helps to make the appearance of this butterfly very distinct from that of any other. Although this species is at times so abundant that it swarms in great flocks and although it has been known for many years, its life-history seems not to have been care- fully worked out since it was first described by Abbott more than a century ago. The caterpillars feed upon cruciferous plants and when full grown are about an inch and a half long, of a general yellow color, more or less THE TRIBE OF THE WHITES 91 striped with purple lines. The species is distinctly trop- ical extending northward into our Southern states. Dr. G. B. Longstaff reports this species as abundant in Jamaica where he found that the clubs of the antennae of the living insects showed a beautiful turquoise blue color, although another observer described them as bright green with a tinge of blue. This is an interesting color variation for a member of this group. In the tropics also there are two forms, one belonging to the dry season and one to the wet season. Synopsis of the Whites Imported Cabbage Butterfly {Pieris rapae). Expanse 2 inches. Upper surface white with a black marginal dash on the front outer angle of the front wing. One round black spot on each of the four wings in the male. Two round spots on each of the front wings in the female and one round spot on each of the hind wings. Under surface of hind wings yellowish white; spots on front wings in same position as on upper surface. A spring form (immaculata) is smaller and the black spots are almost obsolete. Gray-veined White (Pieris napi). Expanse 2 inches. Upper surface white with only a darker marginal splash next the body. Under surface white with gray veins. Checkered White {Pontia protodice or Pieris protodice). Expanse 2 inches. Upper surface white, strongly marked especially in the female with dark grayish brown on both pairs of wings. Along the outer margins these marks are so arranged as to enclose white diamond spots. Male with front wings only lightly marked and hind wings scarcely marked at all. Under surface much like upper, with a slight yellowish tinge in female. 92 BUTTERFLIES Great Southern White (Pontia monuste or Pieris phileta.) Expanse 2| inches. General color white with a nar- row black margin around apical angle of front wings. These margins are wider in the female, in which sex there is a series of marginal spots on the hind wings. Easily known by its large size. THE TRIBE OF THE ORANGE-TIPS When one sees a gossamer- winged butterfly flitting from flower to flower on a bright June day it seems one of the most ethereal of earth's visions. One could readily fancy that the whole sight — flowers, butterflies, and all — might easily vanish into thin air. So it is something of a shock to hear scientists talk about fossil butterflies and to realize that these fragile creatures have been living generation after generation for untold millions of years. A realiza- tion of this fact, however, helps us to understand the many wonderful ways in which butterflies in all stages of their existence have become adapted to the conditions of their lives. There is perhaps no group of butterflies whose beauty seems more fragile than that of the Orange-tips. These are delicate creatures, with slender bodies and almost gauzy wings, of a size somewhat smaller than our common white and yellow butterflies. Perhaps the most remark- able feature is the marking of the wings, the upper sides of the front pair having an orange patch near the apex and the under sides having a background of delicate whitish or yellowish green, lined and spotted with darker coloring in a very characteristic way. This peculiar marking is so THE TRIBE OF THE ORANGE-TIPS 93 significant that it has been called "flower picturing." To understand the reason for its existence one has only to watch the butterflies in their native haunts. He will find them flitting from blossom to blossom among the plants of the mustard family — the Cruciferae. This is one of the most characteristic families in the plant world : the foliage for the most part is small and delicate and the flowers have a characteristic four-petaled structure, being practically always of small size and generally toned in whites or yellows. When an Orange-tip is at rest upon these blossoms it merges so completely into the back- ground that it disappears from view. Should a bird chase one of these insects through the air it would see chiefly the orange tips which are so marked upon the upper side of the wing, and when the butterfly closed its wings and lighted among the flowers the orange color would instantly disappear and there would be only an almost invisible surface against the background of flower and leaf. The adaptations of these Orange-tips to the conditions of their fives are by no means confined to this remarkable re- semblance to the flowery background. In the case of some species the whole yearly cycle has been adapted to cor- respond to the yearly history of the cruciferous food plant. As is well known many species of the mustard family spring up early in the season, put forth their blossoms which quickly develop into fruits and then die down, the species being carried through until the next year by the dormant seeds. In a similar way the Orange-tips feed as cater- pillars upon the host plant through the spring, completing their growth before the plant dies and then -changing to chrysafids which remain dormant through summer. 94 BUTTERFLIES fall, and winter and come forth as butterflies early the fol- lowing spring. The insect has thus adapted itself in a most remarkable manner to the yearly history of its plant host. The Falcate Orange-tip Synchloe genutia The Falcate Orange-tip is about the only member of this tribe generally distributed east of the Rocky Moun- tains. This is a beautiful insect which is sparingly found even as far north as New England. It is more abundant throughout the Southern states, occurring south at least as far as Texas. It appears to be a good illustration of the adaptation of its development to that of its food plants. The eggs are laid upon leaves or stems of such spring- flowering Cruciferae as rock cress (Arabis), and hedge mustard (Sisymbrium) . On hatching the caterpillars feed upon stems, leaves, flowers, and even seed pods of these plants, becoming mature in a few weeks and changing to chrysalids under the protection of such shelter as they can find. In the Northern states these chrysalids remain un- changed until the following spring when the butterflies emerge and are found upon the Egg of synckjoe wiug for a fcw wccks in May and early June. genutta, magnified ^ . ?From^iS)fiand)^" ^^ somc southcm Tcgious at Icast the species is evidently double-brooded, as Dr. Holland reports that he has taken the butterflies in late autumn in the western portion of North Carolina. This Falcate Orange-tip is one of the daintiest and most exquisite of northern butterflies. It is a prize which any THE TRIBE OF THE ORANGE-TIPS 95 collector will find joy in possessing. It is easily recognized by its general white color, which in the female is relieved only by a distinct black mark on the upper surface of the front wings and a row of marginal markings upon all the wings. The male is slightly smaller and is at once known by the orange blotch on the outer angle of the upper surface of the front wing. This outer angle projects into a distinct point which gives the species its name Falcate. {See plate, page 256.) Dr. J. L. Hancock has described in a most interesting manner the way in which this Orange-tip loses itself among the flowers of rock cress. In northern Indiana he found this butterfly abundant in April at the time of the blossom- ing of Arahis lyrata. The butterflies would be flying about, easily seen in the air. Then they would suddenly disappear and could be found only after the most carefiJ search. They had simply lit upon the flower heads, when the flower picturing of the under surface of the wings blended perfectly with the appearance of the clustered flower. "The green markings of the under side of the wing," writes Dr. Hancock, "are so arranged as to divide the ground color into patches of white, which blend with or simulate perfectly the petals of the clustered flowers. The eyes of the butterfly are delicate pale green and the antennae are whitish, all of which adds to the effectiveness of the blend. The flowers of Arahis have white petals with the centre yellowish green, as is also the calyx. There is a shade of pink outside the base of the petals. All in all, the adaptation of insect to flower here displayed is one of rare exquisiteness."* *"Nature Sketches in Temperate America", p. 83. 96 BUTTERFLIES Dr. Hancock found that the butterflies were able to cling on the flowers during strong winds very persistently, so that even when a storm blew across the sand dunes they were likely to remain in position. They also have the in- stinct to rest very quietly after they have lit upon the clustered flower heads. The Olympian Orange-tip Synchloe olympia In various parts of the Southern states there is at least one other Orange-tip butterfly which is found occasionally in connection with the Falcate Orange-tip. It was named Olympia many years ago by William H. Edwards. It is a delicate white species marked with black and yellow very lightly both above and below, the yellow showing only on the under side of the hind wings and that part of the front wing which is exposed when the insect is at rest. Strictly speaking, this is not an Orange-tip because the orange color is lacking in both sexes. This is rather a rare species which occurs occasionally from the Atlantic states to the Great Plains south of a line drawn from northern Maryland to northern Missouri. Like its allies the larvae feed upon various cruciferous plants, the hedge mustard being one of these and the adults visit the flowers of the same family. They doubtless have habits similar to those of the Falcate Orange-tip, and the extreme delicacy of color must render them practically invisible when resting upon the small white flowers of most cruci- fers. Most of the Orange-tip butterflies are found on the ^-^^ From a draiviny by Mary E. Walker THE TIGER SWALLOWTAIL (Reduced) See page 72 Fidiii II ilniirini/ hi/ IT. /. Brcornft Sec jxii/r S. TlIK IMI'OUTED f AliRAOE ni^TTERFLY Cat('r]iillar, dirysalis, mid liutterflies THE TRIBE OF THE YELLOWS 97 Pacific Slope, ranging from Alaska southward, several of them being especially abundant in the western mountain regions. About eight species are recognized as belonging to our fauna, some of which have several well-marked varieties. Synopsis of the Orange-tips Falcate Orange-tip (Synchloe genutia^ Anthocaris genutia or Euchloe geyiutia). Expanse If inches. Tips of front wings projecting in a hooked angle. Orange blotch on upper surface near tip in male, absent in female. Olympian Orange-tip {Synchloe olympian Euchloe olympia or Anthocaris olympia) . Expanse 1| inches. Wings white above in both sexes with greenish black markings at base of all wings and along front margin of front wings, especially at apex. No orange patch. THE TRIBE OF THE YELLOWS A large proportion of our most abundant and conspicu- ous butterflies belong to the Tribe of the Yellows. Some- times it is called the Tribe of the Red-horns because the antennae of the living insects are so often red. These in- sects vary in size from the large Brimstones or Cloudless Sulphurs, expanding three inches, to the delicate little Dainty Sulphur, expanding scarcely an inch. The dis- tinctive characteristics of the tribe are found in the very gradual enlargement of the joints of the antennae that form the club, and the stout palpi, the last joints of each of the latter being short. {See plate, page 113.) 98 BUTTERFLIES The Brimstone or Cloudless Sulphur Callidrayas euhule Practically all northern butterflies are variously marked in different colors, while the butterflies of tropical regions are commonly tinted in monotone, though often showing a splendid iridescence. One with very little experience can tell the look of a tropical butterfly and would be likely to say at once that the Cloudless Sulphur is one of these. The upper surface of the wings of the male is a clear plain sulphur with merely the narrowest possible fringe of brown around the margin made only by the colored marginal scales. The under surface is lighter and sparsely dotted in brown. In the females the marginal brown takes on the shape of a series of small crescents and there is a single round brown eye-spot just in front of the middle of each front wing. While the Cloudless Sulphur is without doubt essentially a tropical species it has an extraordinary geographical range. It is extremely abundant in Mexico, Cuba, and the tropical zone in South America. It extends south even to northern Patagonia and north to New England, Wisconsin, and Nebraska. Presumably in the tropics this species breeds continu- ously, one generation following another in regular succes- sion unless interrupted by drought or other natural phenomena. In our Southern states there is more or less Interruption by the winter season, so that it is commonly considered to have only two broods, the butterflies hiber- nating. Farther north there is probably only one brood in summer, and perhaps not even that in the extreme limit THE TRIBE OF THE YELLOWS 99 of its range. For there is pretty good evidence that the specimens seen in the Northern states are migrants from the south, coming singly or in scattered flocks in early summer, and if they lay eggs the butterflies of the new generation return south in autumn. But the precise con- ditions are not well known and need careful observations in various localities. The life-story of a generation of these butterflies is much like that of the other Yellows. The eggs are laid, one in a place, on the leaflets of various species of wild senna (Cassia) and soon hatch into cylindrical caterpillars that devour the tender leaflets. In a few weeks the cater- pillars mature and change to curious and characteristic chrysalids. The head projects in the shape of a cone and the back is so concave as to give the side view of the chrys- alis a very striking appearance. Like so many of the Yellows this butterfly is sun-loving and social in its habits. Great numbers flock together, their large size and bright coloring rendering them very conspicuous. They often alight on the ground to sip moisture when they have been likened to beds of yellow crocuses. They also fly long distances in flocks that at- tract much attention. It is likely that the northward dis- tribution takes place in summer through such migrating hosts. Other Sulphur Butterflies The Large Orange Sulphur is a closely related butter- fly of about the same size, in which the coloring is uni- formly orange-yellow instead of lemon-yellow. It also be- longs to the tropics, occurring in our extreme Southern states and ranging occasionally as far north as Nebraska. 100 BUTTERFLIES The Red-barred Sulphur is another splendid butterfly, somewhat larger than the Brimstone, which is easily dis- tinguished by the broad reddish bar across the upper sur- face of the front wings. It is tropical but migrates rarely even as far north as Indiana, Illinois, and Wisconsin. The Dog's-head Butterfly Meganostoma caesonia The Dog's-head butterfly furnishes one of the most re- markable examples of accidental resemblance in wing markings that can be found in the whole order of scale- winged insects. It is comparable with the skull and cross- bones on the back of the death's-head moth. In the butterfly the middle of the front wings has a broad band of yellow against a black margin on each side and the yellow outlines make an excellent silhouette of the profile of a poodle with a large black eye-spot in exactly the proper place. The females are less brightly colored than the males but they still show the dog's-head silhouette. This is a southern species, which occasionally strays as far north as New York City, New Hampshire, Wiscon- sin, and Iowa. The larvae feed on species of Amorpha and are believed to be three-brooded in southern regions where the butterfly occurs. {See platCy page 113.) The California Dog's-head is even more beautiful than the southern species. It is remarkable for its pink and purple iridescence — a characteristic which is not com- mon in the butterflies of the Yellow and the White Tribes. The silhouette of the Dog's head is less perfect than in the more eastern species, and the yellow color tones are THE TRIBE OF THE YELLOWS 101 more tinged with orange. The female is strikingly dif- ferent, the wings being plain pale yellowish buff marked only with a round blackish eye-spot near the middle of each front wing and the barest suggestion of a dark line around the extreme margin. The Clouded Sulphur Eurymus philodice It is an interesting fact that the butterfly which one is most likely to find in fields and along roadsides during practically all the weeks of summer has seldom if ever been noted as a destructive insect. The Clouded Sulphur is probably the commonest species in its group. There may be times when the White Cabbage butterfly or other forms are more abundant, but the Clouded Sulphur re- tains its place season after season, with comparatively little noticeable variation in its numbers. This is doubt- less an illustration of an insect which has established such relations with its food plants and its various insect and other enemies that it remains in a fairly stable equih- brium — an example of what is often called the balance of nature. The Clouded Sulphur is about the only medium-sized yellow butterfly generally found in the Northeastern states. It will easily be recognized from the accompany- ing pictures, opposite pages 112, 113. The adults may be seen from spring until autumn. They lay eggs upon clover and other plants. These eggs hatch into small green caterpillars that feed upon the leaves and are protectively colored so they are comparatively seldom seen. When 102 BUTTERFLIES the food plant is disturbed they drop to the ground, crawl- ing up again upon stems and leaves when the distiu-bance is over. These caterpillars moult several times during their growth. When full grown they find such shelter as they are able and each spins a silken web over part of the sur- face. It then fastens its hind legs into this web and later spins a loop near the front end of the body. It pushes itself beneath this loop and waits for several hours before the skin breaks open along the back and is gradually shuflOled off reveahng the chrysalis in position. A week or two later the fully developed butterfly emerges from the chrysalis. These yellow butterflies lend a distinctive charm to our summer landscapes. They are constantly to be seen fluttering from place to place, lightly visiting flowers of many kinds from which they suck the nectar, and gather- ing in great colonies by roadside pools where they seem to sip the moisture. There are many references to this insect in the writings of New England authors. It evidently was an especial favorite of James Russell Lowell who has often referred to it in passages like this: " Those old days when the balancing of a yellow butter- fly over a thistle bloom was spiritual food and lodging for a whole forenoon." The Orange Sulphur Eurymus eurytheme Were one able to take a Clouded Sulphur butterfly and change the yellow to a deep orange color he could easily make a specimen that would pass for the present THE TRIBE OF THE YELLOWS 103 species. The resemblance is very remarkable and shows the close affinity between these two beautiful insects. Like so many others of this group the Orange Sulphur is essentially a tropical species. In the eastern United States it is rarely found north of latitude forty degrees, but south of that it becomes increasingly abundant as one approaches the tropics. It occurs from the Carolinas to Texas, and over the great range in which it Hves it takes on many different forms and habits. It is one of the most remarkable examples of variation in coloring exhibited by any of the butterflies. Nearly a dozen species names have been given to its various disguises, all of which are now recognized as synonyms. In the more northern regions where it is found, only one of these forms usually occurs, but in other places bright yellow and pale white varieties are found. (See plate, page 113). The life-history of this butterfly along latitude forty degrees is very similar to that of the Clouded Sulphur. There seem to be usually two broods and the caterpillars live upon leguminous plants, especially alfalfa, buffalo clovers, wild senna, and other species of Trifolium and Cassia. Apparently also it hibernates in both the cater- pillar and the butterfly stages. In the extreme Southwest — as on the plains of Texas — the vegetation dries up completely in summer so that there is no succulent leafage for the caterpillars to live upon. In such cases the insect must aestivate rather than hibernate. This species apparently succeeds in doing this by having the caterpillars go into a more or less lethargic condition in which they pass the summer. The adult butterflies utterly disappear in June and are not seen again until early in autumn when the autumn rains have 104 BUTTERFLIES started the growth of vegetation anew. The insects then make up for lost time and produce several broods in rapid succession. In the Imperial Valley of California this butterfly is a serious pest to alfalfa growers. It continues to reproduce throughout a very long season, one brood following another from March until December, and in mild winters there seems sometimes to be practically no cessation of its activities. Mr. V. L. Wildermuth found that the devel- opment of a generation in breeding cages in this valley varied from twenty-two to forty-four days, the latter in cool, the former in hot weather. The stages in the first and the third broods in spring varied thus: Egg, first six days, third four days; larva, first thirty days, third twelve days; chrysalis, first eight days, third five days. In this case the first generation extended from March 15 to April 30 and the third from May 28 to June 20. After the fourth brood of butterflies there was such an overlapping of the various stages that it was impossible to distinguish the broods. The Pink-edged Sulphur Eurymus interior This beautiful butterfly was first made known to the world of science by Louis Agassiz, the great naturalist who did so much to arouse a scientific interest among Americans. He found it on a famous expedition to the northern shores of Lake Superior, which not only served to bring to light many interesting phases of geological history but also laid the foundation for the copper mining THE TRIBE OF THE YELLOWS 105 industry which has since become so important in that region. The butterfly thus brought to hght has been found to be a characteristic northern species, occupying a rather narrow belt nearly along the fiftieth degree of latitude and extending west almost to the Pacific Coast. The species is occasionally taken as far south as the White Mountains and there are indications that in this region there are two broods a year. The male butterflies are known at once by a beautiful pink edge on all the margins; they bear otherwise a close resemblance to our common Sulphur Yellow. The females are much lighter in color, often having no black markings on the upper surface of the hind wings. The Black-bordered Yellow Eurema nicippe This is essentially a tropical butterfly which has spread out over most of our Southern states where it is abundant and widely distributed » It adds a distinct touch of color and life to many landscapes when the butterflies swarm by thousands upon clover blossoms and other low vege- tation. The eggs are laid upon the leaves of clover and more especially upon some common species of Cassia, such as wild senna. Each egg soon hatches into a small greenish cylindrical worm, colored and striped in such a way that as it rests upon the leaf it is easily overlooked. This larva develops rapidly and soon becomes about an inch and a quarter long, being rather slender and fairly smooth. It now spins a bit of silk upon a twig or some similar support and also the frailest sort of a silken loop 106 BUTTERFLIES to pass around its back. It now entangles its hind feet in the bit of silk and soon casts off its last caterpillar skin, emerging as a curious looking chrysalis about three quarters of an inch long with a remarkable pointed pro- jection on the front of the head. When seen through a hand lens this pointed projection and the well-developed characteristic wing sheaths give the chrysalis a remarkable resemblance to some of the twig hoppers or Membracids. The colors vary considerably with the surroundings but are commonly toned in various shades of green and yellow brown. A little later each chrysalis breaks open to disclose one of the beautiful butterflies. {See plate, page 113.) The conditions under which this butterfly lives at the limit of its northern range are not well determined. It is probable that many of those seen here have flown from considerably farther south, and that these migrants lay eggs from which a brood of butterflies develops, these native born appearing late in summer. Presumably the latter hibernate, but whether they can do this successfully under the rigorous conditions of our northern winters has never been determined. In fact, Scudder wrote some years ago that no caterpillars had ever been found in New Eng- land. Here is an interesting opportunity for some young observer to make a real contribution to science. The Little Sulphur Eurema lisa Were one to imagine a Clouded Sulphur butterfly re- duced to half its usual size and built with a corresponding THE TRIBE OF THE YELLOWS 107 delicacy of structure, one would have a pretty good idea of the beautiful little creature called by the above name. I well remember in my college days taking what was prob- ably the first of these butterflies ever collected in the re- gion of our Michigan college. It was a prize that very likely had wandered north from Indiana but which served to add much glory to the little collection in which I took such pride, for this is essentially a southern species In many regions of the South it is so abundant that it can be taken by any one. It ranges from coast to coast and extends south into the tropics. In the eastern region it is found from southern Wisconsin to southern New England, occurring sparingly and locally in various places along the line thus indicated. The food plant of the species is chiefly wild senna or other kinds of Cassia. The mother butterflies deposit the eggs singly on leaves or stems, generally on the small leaflets of the compound leaf. Less than a week later each egg hatches into a cylindrical greenish caterpillar that feeds upon the leaflets in a characteristic fashion. Instead of devouring the blade from the margin inward it gnaws narrow strips between the smaller veins. When not feeding, the caterpillars protect themselves from observa- tion by birds or other enemies by resting motionless along the stem of the leaflet or else along the midrib on the under side. As is well known the leaflets of Cassia, like other leguminous plants, close at night. It is probably on this account that these caterpillars feed chiefly by day. The general green color of the skin and the straight stripe along the side help to make this caterpillar very inconspicuous when it is at rest. When full grown the caterpillar reaches a length of three 108 BUTTERFLIES quarters of an inch. It now finds some bit of shelter on which it spins a bit of flat web and a silken loop to hold it in place as it becomes a chrysalis. It then changes and remains quiescent for ten days or more when it emerges as the dainty butterfly. Notwithstanding its abundance and its successive broods its life-history is none too completely worked out. There is still opportunity for careful observations upon the way in which it passes the winter in various parts of its range. While in the South it apparently hibernates as an adult, this fact is not certain in the more northern localities. Notwithstanding its diminutive size this butterfly has been known to swarm in such enormous numbers as to seem a veritable cloud. The most notable record of this has been quoted by Scudder in connection with a swarm that invaded the Bermuda Islands, in 1874, on the first day of October. It was described in these words: "Early in the morning several persons living on the north side of the main island perceived, as they thought, a cloud coming over from the northwest, which drew nearer and nearer to the shore, on reaching which it divided into two parts, one of which went eastward and the other westward, gradually falling upon the land. They were not long in ascertaining that what they had taken for a cloud was an immense concourse of small yellow butter- flies, which flitted about all the open grassy patches in a lazy manner, as if fatigued after their long voyage over the deep. Fishermen out near the reefs, some few miles to the north of the islands very early that morning, stated that numbers of these insects fell upon their boats, literally covering them." THE TRIBE OF THE YELLOWS 109 As is the case with so many of the related yellow butter- flies there is an albino variety of this species. It has been given the variety name alba although it is really a pale yellow rather than a true albino form. The Dainty Sulphur Nathalis iole While the Little Sulphur butterfly seems about as delicate a creature as one could ask to see, it loses that dis- tinction when it is compared with the still smaller Dainty Sulphur. The latter expands scarcely an inch when its wings are stretched apart, and its slender body and an- tennae help to give the suggestion of extreme delicacy. There is more marking of black upon the sulphur-yellow wings than is the case with the larger form, the upper por- tion of the front wings showing only a broad yellow band upon a background of darker color. The under wings are nearly all yellow. Synopsis of the Yellows Brimstone or Cloudless Sulphur {Callidryas euhule or Catopsilia euhule) . Expanse 2| inches. Upper surface of male clear, light, sulphur yellow. Female with a brown spot in front of middle of each front wing and a narrow brown margin on all the wings. Under surface deeper yellow with sparsely scattered brownish dots. Red-barred Sulphur {Callidryas philea or Catopsilia philea). Expanse 3 inches. Easily known by the reddish orange bars on the sulphur-yellow wings. Large Orange Sulphur {Callidryas agarithe or Catopsilia 110 BUTTERFLIES agarithe). Expanse 2| inches. Distinguished at once by its uniform orange-yellow color. Dog's-head Butterfly {Zerene caesonia, Colias caesonia or Meganostoma caesonia). Expanse 2| inches. Upper sur- face yellow with black inner and outer borders on front wings and black outer border on hind wings. The black and yellow of each front wing so combined as to make a distinct dog's head with black eye. Clouded Sulphur {Eurymus philodice or Colias philodice) . Expanse 2 inches. Upper surface sulphur yellow with blackish borders, the yellow brighter in the male than in the female. Male with line between yellow and black distinct, a black spot just in front of the middle of each front wing and an orange spot near the middle of each hind wing. Under surface of male deeper yellow, with spots as on the upper surface but without black margin, and with a row of sub-marginal brownish dots on each wing. Female with upper surface more generally suffused between mar- ginal mark and the yellow part with more or less duskiness both above and below. Spots on each wing much as in male. In the white form of the female (pallidice) the yellow is replaced by white. Pink-edged Sulphur {Eurymus interior). At once dis- tinguishable from philodice by the narrow pink edge of all the wings, showing both from above and from below, slightly smaller as a rule. Orange Sulphur {Eurymus eurytheme or Colias eury- theme). Expanse 2 j inches. Much like Clouded Sulphur in markings except that prevailing color-tone is orange yellow. Black-bordered Sulphur {Eurema nicippe, Xanthidia nicippe or Terias nicippe). Expanse 2 inches. Upper THE TRIBE OF THE YELLOWS 111 surface of wings bright orange with a small black dash in front of the middle of each front wing and a broad black border on all the wings. In the females the borders are in- terrupted at the rear. Under surface slightly brownish yellow, minutely striated and clouded when exposed when the butterfly alights. Little Sulphur {Eurema euterpe, Eurema lisa, Xanthidia lisa or Terias lisa) . Expanse 1 inch. Easily known by its small size and delicate structure. Upper surface of wings yellow with distinct black borders. Under surface yellow with indistinct spots. Dainty Sulphur {Nathalis iole). Expanse 1 inch. Easily known by its small size and narrow yellow wings with black bars across the outer angles and black bands across the back border of the front wings and the front border of the hind wings. The Nymphs Family Nymphalidae A large proportion of our most familiar butterflies belongs to this family. The Fritillaries, the Angle-wings, the Sovereigns, and the Emperors are tribes in which practically all the species are of medium or large size. The Crescent-spots include a few which are rather small. The combinations of characters by which the Nymph family is distinguished are these: Front legs dwarfed into lappets; scaly antennae; veins of fore wings not swollen at base; wings of normal shape, not much longer than wide. Larvae cylindrical, but varying greatly in form, 112 BUTTERFLIES color, and skin coverings. Chrysalids angular in most species, in others rounded. The stories of the lives of the many members of this family vary considerably, as one would expect from their variety and numbers. We may take, however, the life of the familiar Antiopa or Mourning Cloak as typical of the group. Briefly summarized, its story may thus be told: During sunny days in spring one may often see a beauti- ful purple-back butterfly, having a cream-colored border along the outer margin of its wings, flying leisurely about, in the vicinity of woods and in the open fields. This in- sect is called the Antiopa or Mourning Cloak; it is repre- sented natural size in plate opposite page 145. It has passed the winter in this adult condition, having found shelter in some retreat where it is not directly exposed to the storm and stress of the weather. When the leaves of the elm, willow, and poplar trees are nearly expanded, these butterflies deposit their eggs upon the twigs. These eggs are laid in clusters encircling the twigs, there being twenty or more in each cluster (see pic- ture on page 113). In the act of oviposition, the butter- fly keeps her wings spread out, moving the body and abdo- men about as the placing of the eggs necessitates. About two weeks after the clusters of eggs are thus laid upon the twigs of the food plant, they hatch into small blackish caterpillars, each emerging from the egg shell through a small hole that it eats out of the upper surface. They thus enter upon the second stage in their life-his- tory— the larva or caterpillar stage. As soon as hatched, they crawl to the nearest leaf upon which they range them- selves side by side, with their heads toward the margin of the leaf. They feed in this position, nibbling at the green /•'/■()»/ (( ilnnr/Ni/ liij Man/ /•,'. W'dlkcr S,i /)(),/< /('/ THK TLOrnED .STTIJMUR hi TTKUI'L^ (";ilirpill;ir .irnl liiil Irrfly on rrd cldNcr plant. ( Ht'diued) See page 76 THE ZEBRA SWALLOWTAIL Summer form: upper surface, above; under surface, below From a (hairing by Mary E. Walker See page 76 ZEBRA SWALLOWTAILS N'isiting hlossoniing brunches of tho T)awpaw tree. (Tleduced) Srr jHUjrs '.17-11.', SOME OF THK TRIBE OF YELLOWS Tpper siirfiifes at left; undi^r siirfiices at rijilil (1) 'I'll.' lUack-hnnleml Yellow — male; ('2) llie Clouded Siilj)liiir -male; (.'!> the Orange SmImIiui — female; (4) llie I )o«"s-liead— male THE NYMPHS 113 surface of the leaf-blade and leaving the network of veins untouched. These caterpillars continue to feed in this manner for about a week, remaining side by side when feeding, and marching in processions from one leaf to another as the food supply is exhausted. Wherever they go, each spins a silken thread on the surface traversed, so that the combination of all the threads makes a sort of carpet that serves as a foothold for the caterpillars. At the end of the week they moult or cast their skins, a process in which the skin of each larva splits open along the back, and the larva crawls out covered with a new skin that had been formed beneath the old one. This new skin stretches ing-cioak, laid in a cluster on a twig. somewhat after the caterpillar emerges, so (^™°^ HoUand). that the insect is able to increase considerably in size. At the period of moulting, the caterpillars remain quiet for a short time, but they soon become active again and begin feeding with increased voracity. During the next three weeks, this moulting process is re- peated three times, the caterpillars becoming larger each time, and leaving their cast skins upon the denuded twigs. They soon scatter more or less over neighboring leaves, but remain in closely associated colonies. As they increase in size, they eat more and more of the leaf substance; when half grown, they devour all but the mid-rib and the side veins; but when they get larger, only the midribs are left. The carpet web that they form becomes more conspicu- ous as the caterpillars become full grown. They then leave the tree or shrub on which they have been feeding, and scatter about, seeking some sheltered situation. Hav- 114 BUTTERFLIES ing found this — perhaps beneath a stump or along the under side of a fence — each caterpillar spins a web of silk along the surface. It then entangles the hooked claws of its hind legs in the silken web, and lets its body hang ver- tically with the head end curved upward. It remains in this position some hours before the skin along the back just behind the head splits apart and is gradually wriggled upward, until finally it is all removed and there hangs in place of the caterpillar a peculiar object having no definite form. But it rapidly assumes a definite form — that of the chrysalis — which is grayish brown, different specimens varying somewhat in shade. In this quiet chrysalis, the insect is apparently almost as inert as a mummy. If you touch it it will wriggle a little, but otherwise it hangs there mute and helpless. On the in- side, however, the tissues are being made over in such a wonderful way that, in about two weeks, from the mummy case into which the caterpillar entered there comes a beautiful butterfly. When tliis butterfly first breaks through the mummy shell, its wings are very small, although its body, antennae, and legs are well developed. By means of the latter, it clings to the empty chrysalis, while its wings expand. At first these wings are short, but as soon as the insect takes a position in which the wings hang downward, they begin to expand, and soon reach full length, but are more or less crumpled longitudinally, and the front wings are not so wide as the hind ones, hanging limply inside the latter. After the butterfly has thus reached its full form and size, it crawls from the chrysalis to some neighboring support, where it rests quietly for half an hour or more. During the latter part of this time it exercises its un- THE TRIBE OF THE FRITILLARIES 115 used muscles by slowly opening and closing its wings, until it finally flies away. THE TRIBE OF THE FRITILLARIES This is one of the most distinctive tribes of the family of Nymphs. The clubs of the antennae are about twice as long as broad and curiously spoon-shaped. The palpi are large and bushy, with the last joint very short. Most of the species are rather large and practically all are beautifully mottled in various tones of brown, red, black, and silvery gray. A large proportion of our midsummer butterflies are members of this tribe. The Gulf Fritillary Agraulis vanillae In tropical America there is a genus of butterflies called Agraulis. These are fairly large insects, approximating the size of the Viceroy, which show most beautiful colors in the tropical sunshine. One member of this genus has come north to our Southern states, and is occasionally found as far up as Virginia and southern Illinois, extending below this from ocean to ocean. It reveals on its upper surface the most exquisite tints of iridescent purples and browns, suggesting by its form and color as thus seen a tropical species. The lower wing surface, when the wings are closed in their natural position, shows only a spangled effect of silver- white and brown, which is very suggestive of the under surface of our northern Spangled Fritillaries. So this beautiful species may fittingly be called the Gulf 116 BUTTERFLIES Fritillary, carrying over from the north some of its peculiar beauty and connecting with the equally distinctive beauty of the tropical south. {See 'plates, pages 128, 129). Like so many other southern butterflies the eggs of this species are laid upon the leaves of passion vines. The caterpillars develop very rapidly and when matured are yellowish or brownish yellow, striped with darker lines along the back and sides. There are black branching spines, arranged in rows beginning on the head and run- ning backward on the body. The whole cycle of hfe from egg to butterfly may take place within the short period of a month and one brood succeeds another in so irregular and rapid a fashion that it is difl5cult to determine definitely the number of broods in a season. The Variegated Fritillary Euptoieta claudia There is something in the appearance of the upper sur- face of this butterfly that suggests the other Fritillaries on the one hand and the Emperors on the other. The coloring and marking is a bit like the former and the shape of the wings like the latter. The general color is a golden brown with darker markings arranged in bands and eye-spots in a rather complicated pattern. The under surface, so far as it is exposed when the butterfly is at rest, is a beautiful marbled combination of gray and brown which is probably distinctly obliterative in the haunts of these insects. The front wings have the outer margin concave in the middle, giving a special prominence to the shape of each front outer angle. THE TRIBE OF THE FRITILLARIES 117 This butterjBy is a southern rather than a northern spe- cies, but it is found occasionally from Montana to Massa- chusetts and southward to Arizona, Mexico, and Florida. Even in northern Indiana it is very seldom found and is considered rare in the southern part of that state. Around Buffalo, New York, it is also rare and is not common in the vicinity of New York City. In the more Southern states, however, it is abundant and extends well through the con- tinent of South America. There is considerable evidence to indicate that this butterfly hibernates as an adult. In the more southern regions it probably also hibernates in other stages, es- pecially the chrysalis and the larva. In regions where it is double-brooded, as it appears to be in the latitude of New York City, the seasonal history seems to run some- thing like this: the partly grown caterpillars which have passed the winter in shelter at the surface of the soil feed upon the leaves of violets and certain other plants. They change to chrysalids, probably in May, and emerge as butterflies in June. These butterflies lay eggs for a sum- mer brood of caterpillars which may feed upon the leaves of violets, May apples, portulaca, and stonecrop. They grow into cyhndrical worms of a general reddish yellow color, marked by longitudinal stripes of brown upon the sides and a row of whitish dots upon the back. They become matured in time to disclose the butterflies of the second brood in August and September. Presumably these butterflies lay eggs that develop into caterpillars which hibernate when partially grown. Farther south there are probably three broods a year and hibernation may take place in various stages. There is good opportunity for careful work in determining the 118 BUTTERFLIES life-history of the species in different latitudes. The butterfly is found in much the same situations as the other Fritillaries, flying over meadows and along the borders of woods. The Diana Fritillary Argynnis diana This magnificent butterfly differs from the other Fritil- laries in the fact that the females are so unlike the males that only a skilled naturalist would even guess that they are related. Both sexes are rather rare and are found only in a comparatively narrow range extending from West Virginia to Missouri, northward to Ohio and Indiana, and southward to Georgia and Arkansas. This species was first described by Cramer a long time ago from specimens of the male sex. It was later described by Say and other writers all of whom saw only the males. The other sex was first recognized by William H. Edwards, whose account of its discovery as given in his splendid work on the Butterflies of North America is worth quot- ing: "No mention is made of the female by any author," wrote Mr. Edwards, "and it seems to have been unknown till its discovery by me in 1864 in Kanawha County, West Virginia. On the 20th August, I saw, for the first time, a male hovering about the flowers of the iron- weed {Vernonia fasciculata), and succeeded in taking it. Two days afterwards, in same vicinity, while breaking my way through a dense thicket of the same weed, hoping to find another Diana, I came suddenly upon a large black THE TRIBE OF THE FRITILLARIES 119 and blue butterfly feeding so quietly as to allow me to stand near it some seconds and watch its motions. It seemed to be a new species of Limenitis, allied to Ursula, which it resembled in color. But on taking it, I saw it was a female Argynnis, and the general pattern of the under wing left little doubt of its affinity to the Diana male, despite its total difference in color and of upper sur- face. Subsequent captures confirmed this conjecture, and out of the large number that have since been taken the males have been of the known type and the females black, with no tendency in either to vary in the direction of the other. "When my attention was called to the species I found it not very uncommon, always upon or near the iron-weed, which is very abundant and grows in rank luxuriance upon the rich bottom lands of the Kanawha River, fre- quently reaching a height from eight to ten feet and in August covered by heads of purple flowers that possess a remarkable attraction for most butterflies. Both sexes are conspicuous, the males from the strong contrast of color and the females from their great size and the habit of alighting on the topmost flower and resting with wings erect and motionless. It is an exceedingly alert and wary species, differing in this from our other Argynnids. At the slightest alarm it will fly high into the woods near which, upon the narrow bottoms or river slopes, it is invariably found. It is a true southern species, sensi- tive to cold, not to be looked for in the cooler part of the morning but flying down from the forest when the sun is well up. From eleven to three o'clock is its feeding time." The life-history of this fine butterfly is similar to that of 120 BUTTERFLIES the lesser Fritlllaries. The butterflies appear from mid- summer onward, the males preceding the females, and the eggs are laid on or near violets in August or September. The larvae hibernate and mature early the following sum- mer. As they approach the chrysalis stage they are rather large velvety black caterpillars with brown heads and rows of fleshy barbed spines that show an orange tint at their bases. There is thus but one generation each year. The Regal Fritillary Argynnis idalia The Regal Fritillary, fresh from the chrysalis, still showing the marvelous sheen of its iridescence, furnishes one of the most beautiful exhibitions of color in the world of nature. Over the whole wing surface there are tiny scales that reflect the sunlight in an almost dazzling man- ner, giving a distinct purplish tone especially to the hind wings. The Regal Fritillary is one of the largest butterflies of the distinctive group to which it belongs. The wings expand some three inches and the rather thick body is more than an inch long. The general ground color of the wings is brown, with distinct markings of blackish which in the hind wings almost obscure the brown. On each of the latter as seen from above there is a distinct row of cream-colored spots across the middle, duplicated by a similar row of brown spots near the margin. The under surface of both pairs of wings is much lighter and thickly mottled all over with light cream-colored spots of a large size and more or less triangular shape. {See frontispiece.) THE TRIBE OF THE FRITILLARIES 121 Like the other Argynnids, the Regal Fritillary is single- brooded during the year and it has a rather remarkable longevity in each stage of its life. The newly hatched caterpillars go into hibernation and live through the winter without feeding, finding shelter at the surface of the ground, especially beneath the leaves of violets which form their chosen food plants. When the snow has dis- appeared and the warmth of the spring sun brings them out of their winter lethargy these tiny caterpillars feed upon the violet leaves and grow slowly for several weeks. They then change to chrysalids, the time for doing this varying considerably with the individual and doubtless with the warmth of the situation in which each is living. The length of time spent in the chrysalis varies also, but in general it seems to be less for those which develop into male butterflies than for the females. It is a curious fact that the former may be found for nearly two weeks before any of the latter appear. The first butterflies of this species are usually disclosed from the chrysalis late in June or early in July. They continue to come forth for several weeks, apparently until nearly the middle of August. They lead a leisurely life, visiting freely the flowers of goldenrod, iron-weed, boneset, Joe Pye weed, and especially swamp milkweed. They are most likely to be found in lowlands and along the borders of swamps where these favorite flowers are growing. It evidently requires some time for the eggs to develop within the ovaries, for the butterfly cannot be- gin laying these until the latter part of August. They apparently are normally deposited on the under side of violet leaves, although so far as I know no butterfly has been seen thus laying her eggs. It would be an interest- 122 BUTTERFLIES ing point for some young observer to determine. Even the eggs take a long time to develop, not hatching for three or four weeks after they are laid. When they do hatch the tiny caterpillars seem not to eat at all but to go di- rectly into hibernation. These butterflies are to be found in their preferred habi- tats almost any time during July, August, and September. Apparently many of them live as adults for nearly three months so that whether we consider the egg, the larva, the chrysalis, or the adult we have in this species an unusual duration of life. This is doubtless an adaptation to the fact that the species must get through the year with only one brood. This unity of habit with no such variations as occur in many butterflies with a wider range north and south is apparently correlated with the distribution of this butter- fly. It is found in a belt of territory running from New England and the Atlantic states westward at least to Nebraska along a line which approximates the annual isotherm of fifty degrees Fahrenheit. The Great Spangled Fritillary Argynnis cyhele To one who wanders much in the woods and open fields there are few summer scenes more characteristic of the season than that of a group of milkweeds in full flower, surrounded by a host of brown butterflies busily sucking the nectar from the curious pink blossoms. There are likely to be several species of these winged creatures, but in many regions of America the largest and most conspicu- THE TRIBE OF THE FRITILLARIES 123 ous will generally be the Great Spangled Fritlllary. This butterfly is easily recognized by its large size and its combination of two colors of brown, with whitish or silverish spots scattered over the lower surface of the wings. The life-history of this insect is of peculiar interest on account of the way in which it passes the winter. The mother butterfly remains upon the wing through many weeks in summer, so that toward the end of August or early September a large proportion of the specimens have a decidedly frayed appearance. They are patiently wait- ing for the season of the year when they can deposit their eggs, apparently knowing by instinct that this must not be done until early autumn. When the proper season arrives they lay their eggs upon the leaves or stems of wild violets, apparently without much reference to the par- ticular species. Sometimes they have been reported simply to drop the eggs loosely upon the violet plant with no attempt to fasten them in place. Having thus deposited the eggs the mother butterflies soon die. It would not seem strange if these eggs remained un- hatched until the following spring, but the fact is that the eggs hatch very soon into small caterpillars that eat off part of the shells in order to escape and sometimes eat also part of the shell remaining after they have emerged. Various good observers have apparently established the fact that these tiny caterpillars eat nothing else before winter sets in. It seems curious indeed that they should not nibble at the leaves or stems of the violet plants in order to be slightly prepared for the long fast that awaits them before they will find food upon the young buds the following spring. The case is somewhat similar to that of 124 BUTTERFLIES the common tent caterpillar which becomes a fully formed caterpillar within the egg shell before the end of autumn, but remains unhatched until the following spring. In the present case the caterpillar hibernates outside of the egg shell rather than within it. When at last the warm sunshine of spring starts the violets into new growth the tiny caterpillars begin feeding upon the succulent tissues. They nibble away day after day for a week or more before they become so large that they have to cast their skin for the first time. They then feed again and continue this process of feeding and moult- ing until early in summer. They are likely to hide them- selves during daylight and have the reputation of being difficult to rear under artificial conditions. The full-grown caterpillar wanders along the surface of the ground in search of suitable shelter for the chrysalis period. When it comes to a large stone with sides pro- jecting more or less horizontally or a log lying upon the ground or even a large piece of loose bark it is likely to stop and change to the pupa or chrysalis. In this con- dition it is dark brown in color and well covered with thickened tubercles, especially along the back of the abdomen. About a fortnight later the chrysalis breaks open and the fully developed butterfly comes forth. It rests quietly for a time while its wings expand and the tissues harden and then sallies forth for its long period of flight; for this insect is single-brooded in the Northern states at least and the butterflies that thus mature late in June or early in July are likely to remain alive until early in September. So they have a comparatively long life for a butterfly that does not hibernate as an adult. THE TRIBE OF THE FRITILLARIES 125 The Silver-spot Fritillary Argynnis aphrodite Our brown Fritillaries are seldom found without several species mingling together. This is not strange, for they have similar habits throughout their entire lives. So when you see a bevy of butterflies collected around the midsum- mer blossoms of the milkweed, you are pretty sure to find that the Great Spangled Fritillary is associated with the Silver-spot and probably one or two other related forms. The Silver-spot is generally decidedly smaller than the one first named and the surest way to be certain of it is to look on the under side of the hind wing and see whether there is a broad band of buff between the two outer rows of silver spots. If this band has disappeared or is nearly all taken up by the brown ground-color of the wing, you may be pretty sure we have the Silver-spot Fritillary. (See plate, page 128.) When one has firmly fixed in mind the life cycle of one of these butterflies, one has a model after which to fashion the rest, for our several species are remarkably alike in this respect. The Silver-spots are on the wing for several weeks in summer. During the latter part of this time the females lay eggs upon violet leaves. These eggs shortly hatch into caterpillars that go directly into hibernation, taking no food before winter sets in. The following spring they feed upon violet leaves and mature in time to change to chrys- alids and emerge as butterflies in early summer. There is but one brood a year and the species is widely distributed over southern Canada and the Northern states. It extends 126 BUTTERFLIES south to Virginia and Pennsylvania and west to Nebraska, Montana, and Washington. The Mountain Silver-spot Argynnis atlantis If one were able to take a Silver-spot Fritillary and re- duce its size about one third he would have a wonderfully good imitation of the present species. Except for the size, about the only difference in the markings is found in the blackish border along the margins of the Mountain Silver- spot which is not present in the other species. The buff sub-marginal border line on the under surface of the wings between the rows of silver spots is also wider in the moun- tain species. The distribution of tliis butterfly justifies its name. It is preeminently a northern species, being especially abund- ant in the White Moimtains of New Hampshire and rang- ing northward far into Canada and west through British America as far as the Mackenzie River. A pair of these butterflies were captured by Merritt Carey on July 16, 1903, on the summit of Mount Tha-on-tha, in the Nahanni Mountains, at an altitude of 2,500 feet. The southern limit of its distribution approximates the isotherm of forty-five degrees. It extends southward in mountainous regions through New York and Pennsylvania and is found in Michigan, Illinois, and Iowa. It also occurs in the Rocky Mountain region of Colorado. The various species of Argynnis show a remarkable uni- formity in their life-history. Like the others, this butterfly is single-brooded, laying the eggs on or near violets late in THE TRIBE OF THE FRITILLARIES 127 summer, the eggs hatching into larvae that take no food until the following spring. They then feed upon the violet leaves, become mature, and change to chrysalids in time for the butterjBdes to emerge in June in New Hampshire. These butterflies remain upon the wing for several weeks. They usually appear a week or two earlier than Aphrodite or Cybele in regions where all three species are found. It is worth while for the collector to take a hint from this fact and do his Silver-spot collecting early. For after the other species appear it is not so easy to tell which is Atlan- tis when the butterflies are on the wing. It is most likely to be found in open places in the woods, apparently pre- ferring such situations to the broad expanse of fields and meadows. The White Mountain Fritillary Argynnis montinus This is distinctly a mountain butterfly, known to be found only near the top of Mount Washington and other neighboring parts of the White Mountains. It generally occurs between the altitudes of four thousand and fifty- five hundred feet. It is doubtless closely related to a somewhat similar form found farther north and west, but its isolation from them is complete. Apparently it is single-brooded and very little is known of the early stages. The butterflies visit the flowers of goldenrod and those of the alpine sand-wort which are abundant in the sub-alpine home of this species. This variety is interesting as a living souvenir of the day when New England was buried beneath the ice-sheet. 128 BUTTERFLIES The Meadow Fritillary Brenthis hellona The fact of variation is one of the most universal things in nature. No two animals are exactly alike and every plant differs from every other plant. That this is true of the structure of living things is easily observed but it is not so well known, because not so easily observed, that most species of animals differ also in the precise phases of their growth. We know that the variation in form and color has brought about the remarkable adaptations to sur- roundings which we call mimicry and protective colora- tion. A little consideration will make it evident that the variation of different individuals in periods of growth must have led also to the adaptation of the life stages to the con- ditions of the changing seasons. This is particularly true in the great majority of insects which show remarkable adaptations in their various broods to the seasonal con- ditions of the localities where they live. From this point of view the attractive little Meadow Fritillary is of especial interest. We are indebted to the studies of S. H. Scudder for our knowledge of the remark- able variations in its growth. These are so complicated that in order to make plain the varying conditions it seems necessary to separate the broods in a somewhat hypotheti- cal manner. We will begin with what we shall call Group A: The butterflies are on the wing in May and early*"June. They have just come from the chrysalis and continue living for three or four weeks before they deposit eggs, this time being required in order that the eggs may develop in the THE SILVEIt-Sl'OT FRITILLAKY Tpper iiiid lower siirfiif-es (xrc iniijc THE (;ULF KinTII.F.AHY Lower SiiiTiice (.vrv luuir 11. 'A ir.) THE GULF FRITILLARY {see page 115) THE SILVFR-BORDFRED FRITILLARY Upper and under surfaces {see page ISl) THE BALTIMORE CHECKER-SPOT Upper and under surfaces {see page hifj) THE TRIBE OF THE FRITILLARIES 129 ovaries of the butterflies. These eggs hatch in about a week and the caterpillars become full grown a month later. They then change to chrysalids in which condition they re- main another week, thus requiring five or six weeks for the newly laid eggs to mature into butterflies. Supposing the eggs were laid the first week in June, the butterflies of this second brood would appear about the middle of July. The eggs in the ovaries of some of these butterflies also re- quire several weeks before they are ready to be laid, so that it may be about the tenth of August when this happens. These hatch and mature to chrysalids during the next six weeks, the butterflies of this brood emerging about the middle of September. These in turn lay eggs at once ap- parently, no extended period being required for their de- velopment before they are laid. The eggs hatch during the latter part of September and the young caterpillars feed upon the violet leaves for two or three weeks, moulting per- haps twice and becoming approximately half grown. They now stop feeding and go into a lethargic condition in which they hibernate. Then in spring they awaken and feed again upon the violet leaves for a short time, becoming mature and changing to chrysalids sufficiently early to emerge as butterflies late in May. In this hypothetical group we have a fairly normal con- dition of a three-brooded butterfly hibernating in the stage of the half -grown larva and requiring some weeks for the development of the eggs in the ovaries of the butterflies in the case of the first two broods but not of the third. In another group, which we may designate as B, the con- ditions may be similar except that the butterflies lay their eggs very soon after coming from the chrysalis in the case of all three broods. Obviously there would be a tendency 130 BUTTERFLIES here for hastening the earhness of the broods so that the hibernating caterpillars might either become larger or might go into the hibernating condition earlier than those of Group A. In Group C, the variation takes place in the larvae rather than in the butterflies. These may go on in the normal way up to the time the caterpillars of the summer brood become half grown. Then they become lethargic, ceasing to feed and to all appearances going into hibernation. They re- main in this condition until the following spring when they come forth from their winter's sleep and feed upon the violets in precisely the same way as the caterpillars of the third brood of Groups A and B. In Group D we have another interesting variation of the larvae. These are the same as C up to the time of be- coming lethargic, that is, the larvae of the summer or second brood become lethargic at the same time as those of Group C but instead of continuing in this condition until the following spring they remain in lethargy only three or four weeks, then they wake up (having apparently then changed their caterpillar minds) and begin to feed, soon maturing and changing to chrysalids from which butterflies emerge late in September or early in October. The result is that these butterflies lay eggs so late that the cold nights come on apace and the little caterpillars apparently take no food at all but go into hibernation immediately. In consequence these must eat for a longer period the following spring, so that the butterflies into which they mature will be likely not to appear until well along in June. It is probable that even this rather elaborate statement does not do justice to all the variations in the development THE TRIBE OF THE FRITILLARIES 131 of this little butterfly. But perhaps enough has been said to help us to understand something of the way in which such insects are able to adapt their life habits to the con- ditions of their environment. It is easy to see that if con- ditions should so change as to give any one of these groups a decided advantage over the others, the tendency would be for the other groups to disappear and for the group of favored habits to survive. The Meadow Fritillary is common in Canada and the Northern states east of the Rocky Mountains. It is foimd especially in lowland meadows and along the bor- ders of swamps, the very situations chosen by the food plants of the larva, the blue and the white violets. The butterflies may be often seen sipping nectar from the various species of mint and related plants found in such situations. It is commonly associated with the Silver- bordered Fritillary, from which it is easily distinguished because it has no silver spots upon its wings. The Silver-bordered Fritillary Brenthis myrina This attractive little butterfly bears a close general re- semblance to the Meadow Fritillary, from which it differs chiefly by the continuous row of silver spots along the bor- der of the under side of both pairs of wings. It is found in the same localities as the other and its life-history is very similar. {See plate, page 129.) The present species is widely distributed in North Amer- ica, being found as far west as the upper Mississippi Val- ley and the Rocky Mountains, and southward as far as 132 BUTTERFLIES the Carolinas. In New England and the Atlantic states it is one of the commonest of the smaller butterflies. Beginning with the butterflies which are seen in the fields and meadows in September, the yearly cycle of this insect may be summarized in this way: the eggs laid in September hatch in a few days into tiny caterpillars, some of which become lethargic at once, while others begin feeding upon the violet leaves and continue thus to feed until they are about half grown. These then also become lethargic and find shelter just above the soil surface where they remain until the following spring. They then begin to feed again upon the violet leaves and at about the same time the other caterpillars which became dor- mant as soon as hatched, also waken and feed upon these leaves. Naturally those which were half grown at the beginning of spring are likely to mature and change to chrysalids two or three weeks earlier than those which were so small at the beginning of the season. Consequently the fresh butterflies will be found from late in May to the latter part of June. Presumably those which first ap- peared have developed from the larger caterpillars and the later ones from the smaller caterpillars. The butterflies of this first brood of the season lay their eggs upon the violet leaves, generally upon the upper sur- face of the blade, but occasionally upon the stems or upon near-by grasses. These eggs hatch in about a week into caterpillars that mature during the next three or four weeks, coming forth as a second brood of butterflies late in July or early in August. These in like manner lay their eggs and develop into a third brood which matures as butterflies in September. These lay eggs that hatch into the caterpillars which live through the winter. There THE TRIBE OF THE FRITH^LARIES 133 are thus three broods of butterflies during the year and it is probable that there is the same remarkable variation in the habits of the different broods that have been found in the case of the Meadow Fritillary. Synopsis of the Fritillaries Gulf Fritillary {Agraulis vanillae). Expanse 2f inches. Apex of each front wing produced into a distinct angle. Upper surface of all wings reddish brown, marked with black spots and an interrupted black border, the border on the liind wings enclosing round red-brown spots. Under surface, so far as it shows when insect is at rest, nearly covered with large silver- white spots. Found only in the more Southern states. Variegated Fritillary (Euptoieta claudia). Expanse 2| inches. Apex of each front wing produced into a distinct angle. Upper surface of all wings fulvous brown, thickly marked with buff and brownish black. A sub-marginal row of black dots on each of the wings, outside of which is a row of buff crescents on the blackish border. Under surface, as it shows when the butterfly is at rest, beauti- fully marbled in creamy browns and deeper browns. No distinct silver spots in either surface. Diana Fritillary {Argynnis diana). Male. Expanse 3| inches. Apex of fore wings rounded. Upper surface of all wings, with a little more than basal half, solid brownish black and the rest of the surface orange-brown, marked with darker brown round spots and vein lines. Under surface light buff, marked with black, with silver crescents and spots on hind wings. Female. Expanse 4 inches. Upper surface of all wings blackish with bluish or greenish iridescence, and marginal third marked with 134 BUTTERFLIES blue spots and stripes. These are more prominent on the hind wings. Under surface slaty brown with prominent silver crescents on the hind wings. Idalia or Regal Fritillary {Argynnis idalia). Male. Expanse 3 inches. Front wings fulvous brown with black spots and markings. Hind wings black except at base with a row of fulvous brown sub-marginal spots and an inner row of whitish or bluish white spots. Female. Expanse 3| inches. Similar to male except for larger size and the fact that the two rows of spots on the hind wings are yellowish brown. Great Spangled Fritillary (Argynnis cyhele). Expanse 3J inches. General color of wings fulvous brown with black markings on upper surface and black and silver markings on under surface. The yellow band between the rows of silver spots on hind wings is broad. There is a distinct narrow fulvous stripe on the upper side of the hind wing just inside the outer margin, and a similar stripe along the margin of the front wing, more or less interrupted by the veins. Silver-spot Fritillary (Argynnis aphrodite). Expanse 3 inches. Similar to the Great Spangled but a little smaller, and with the buff yellow band between the rows of silver spots on the lower surface much narrower and al- most disappearing at the rear. Mountain Silver-spot (Argynnis atlantis). Expanse 2| inches. Known by its smaller size and the black marginal border stripe on all the wings, with no brown line dividing this stripe. Silver-bordered Fritillary (Brenthis myrina). Expanse If inches. Known by its small size and a marginal row of silver spots on the under side of each of the wings, and THE TRIBE OF THE CRESCENT-SPOTS 135 with many other silver spots scattered over the under sur- face of the hind wings. Meadow Fritillary {Brenthis bellona) . Expanse 2 inches. Easily known by the absence of silver spots on all the wings. The wings are long in proportion to their width. THE TRIBE OF THE CRESCENT-SPOTS The members of this tribe have the following combina- tions of characters: scaly antennae, with a short stout club some three times as long as broad, and a pair of slender palpi in which the terminal joint is only about half as long as the middle one. There may or may not be a slight ridge running lengthwise of the naked part of the antennal club. Although more than fifty distinct species belonging to this tribe have been found in North America, very few of these are distributed through the eastern part. Only four are so abundant and widely distributed that they need be treated of here. Baltimore Checker-spot Euphydryas phaeton To the naturahst those islands in the seas which are remote from the mainland have long been of especial in- terest. The life upon them is likely to show the results of many generations of living under unique conditions. The plants and animals are generally distinctive, many of the species having characteristics which differentiate them markedly from those upon the mainland. They show in a thousand ways the effect of isolation and so are 136 BUTTERFLIES of especial value when one attempts to determine the re- sults of unusual conditions upon living things. In a somewhat similar way the peat bogs or sphagnum swamps which occur here and there over a large part of North America are of especial interest, because in a way they are biological islands in which the conditions of a long past age are preserved until the present. These nearly always occur in a little valley surrounded on all sides by hills. Here the water has collected originally into ajpond or lake, which has been gradually filling up through the growth of peat mosses and a special set of other plants that develop in such situations. One can still find many stages in the process. In some bogs the surface will be practically covered, although the water beneath may still be so abundant that the matted moss quakes as one walks over it. Sometimes such bogs are really dangerous be- cause the walker may drop through to the water beneath. In most of the bogs, however, the little lake is nearly filled but shows the surface over a small area. The conditions in these peat bogs have changed little since civilization began. They are relics of an earlier era which have come down to us as types of conditions that once existed very generally. The plant life is unique and consists almost entirely of forms which are found prac- tically nowhere else. There are comparatively few ani- mals living in these peat bogs and all of these are likely to be of especial interest. Among the insects none is more remarkable than the Baltimore Checker-sjxjt but- terfly which has several peculiarities that diflFerentiate it from the other members of the group. It seems to have come down to us unchanged from a far remote past and to be living its tranquil life to-day in precisely the same THE TRIBE OF THE CRESCENT-SPOTS 137 manner as during the time when the mammoth and the mas- todon were Hkely to invade its haunts . {See plate ^ page 129.) The Baltimore is probably the most local in its distribu- tion of any of the butterflies found throughout Canada and the Northern states. It is to be looked for only in peat bogs and swamps, and it has a remarkable unity in its life-history whether it be found in northern Canada or as far south as West Virginia. The butterfly itself is rather large, measuring a little more than two inches across its expanded wings and being colored with an unusual combination of fulvous and yellow upon a black back- ground. It is present as a rule only from about the first of June to the middle of July. The eggs, in bunches of from one hundred to four hundred, are laid upon the leaves of the plant commonly called snake-head or turtle- head {Chehne glabra) . They do not hatch for nearly three weeks; then the little caterpillars emerge together and usually each eats a little of the empty egg shell. They are then likely to form a thin web over the under surface of the leaf beneath which they remain as a small company feeding upon the succulent green tissue. A little later they are likely to begin the construction of a miniature nest by spinning a silken web over the young leaves at the top of the plant. From this time on this silken nest serves as their home, and they utilize it almost as effectively as do our familiar American tent caterpillars the nest which they make in the forks of the wild cherry tree. The Baltimore caterpillars often wander more or less from their tent-like home but they generally come back to feed as well as to moult. If the nest is injured by wind or rain, all the caterpillars turn out to repair it and as the need for new food supplies arises they also unite to enlarge the 138 BUTTERFLIES tent. This habit of working together for the common good is very suggestive of the similar habits of the Ameri- can tent caterpillars. Doors for going in and out are left in the tent during its construction. The tent thus made is likely to be deserted after the first moult and a new and larger one constructed on another part of the plant. Two or perhaps three such nests may be made from the time the caterpillar hatches until after the second moult. The last nest made is very likely to be upon some neighboring bushy plant or at least to include some branches of such a plant if the bulk of the nest is made upon snake-head. For after the third moult the caterpillars stop feeding and become more or less quiet, thus beginning a nine months' fast, during which they are simply to wait until the return of spring. This fast may be begun any time from the middle of August until early in September, and even when brought indoors the cater- pillars cannot be induced to eat. It is evidently the way in which the species has bridged over the winter during the thousands of generations of its existence, and the instinct is so firmly fixed that it cannot be changed. Even in West Virginia, where the caterpillars would have plenty of time during the summer to mature as butterflies that would bring forth another generation of caterpillars that might pass the winter, the condition is the same as in the far northern regions. So within the shelter of the silken nest these Baltimore caterpillars remain from the middle of August until May. Then when the spring sunshine has sufficiently warmed their cool retreats they come forth and feed greedily upon the young leaves. They now soon make up for lost time and complete their growth as caterpillars very THE TRIBE OF THE CRESCENT-SPOTS 139 quickly. When full fed they wander about in all direc- tions, each hunting its own shelter before becoming a chrysalis. Having found a twig or branch that suits their purpose each hangs downward and changes to a brownish yellow chrysalis, more or less marked with black. It re- mains in this condition for about a fortnight, when it comes forth as the Baltimore butterfly which thus appears again about the first of June. These butterflies seem to have some of the character- istics of their unique surroundings. There are very few flowers in the peat bogs and it is significant that the butter- flies instead of flitting from flower to flower, as do most of our familiar species, fly rather in a slow and lazy fashion from leaf to leaf, lighting upon the foliage or frequently upon the surface of the moss or ground. They seem leth- argic and have httle of the animation which we usually associate with the name butterfly. In my mind the Baltimore is associated with the White Mountain butterfly as a survivor of a former geologic period. The latter was developed under colder conditions and now survives only on a few isolated mountain peaks; but the former has survived wherever the peat bog has held its sway during the long ages that the surrounding landscape has been taking on its present-day condition. Many things in the life of the Baltimore point to its primi- tive condition: the laying of the eggs in loose clusters, the long lethargy of the caterpillars, the limited flight of the butterflies — all indicate a creature with habits firmly fixed by long ages of development in a definite environment. No collector should feel sure that the Baltimore is not to be one of his trophies until he has visited in June every peat bog or sphagnum swamp in his locality. One may 140 BUTTERFLIES search years without finding it, and then come across a dozen in a single day. I well remember the interest with which I first found this species on the margin of a great swamp in Michigan when I was eager for every new butter- fly to add to my collection. I had never seen it alive be- fore and the thrill with which the first specimen was cap- tured can be realized only by those remembering similar experiences. Harris's Checker-spot Cinclidia harrisii This little butterfly so closely resembles the Pearl Crescent and the Silver Crescent that on the wing it is easily mistaken for them. It really looks more like them than it does the Baltimore Checker-spot, which is con- siderably larger and darker colored than the present species. This is essentially a northern form occurring only in a narrow strip of country east of Minnesota and Wisconsin, running on the north through southern Canada and on the south through Michigan, New York, and Massa- chusetts. This insect is one of the best-known botanists among all the butterflies. In the very difficult group of asters which has caused endless confusion to human botanists these in- sects seem always able to select the one species — Aster umbellatus. It has been repeatedly found that the cater- pillars would starve rather than eat the leaves of other kinds of asters, and so far as known they have never been found feeding outdoors upon any other. These butterflies appear along roadsides and in open THE TRIBE OF THE CRESCENT-SPOTS 141 fields about the middle of June. They are often very abundant and are much more generally distributed than the Baltimore Checker-spot. A few weeks later the fe- males lay their eggs upon the aster leaves, the eggs being deposited in clusters of twenty or more on the under side of the leaf. Early in July the little caterpillars come forth and remain together in colonies as they feed upon the green tissues of the leaves. Each is able to spin a silken thread so that wherever they go they weave a web and they soon protect themselves with a slight silken shelter, which is suggestive of the nests made by the Baltimore cat- erpillar. They continue to live in this manner for several weeks in July and August, growing rather gradually and becoming approximately half grown before the frosts of autumn. Unlike the Baltimore caterpillars they now de- sert their nests and find shelter at or near the surface of the ground. Here they hibernate, to come forth the following spring and feed again upon the new growth of the aster plants, often doing considerable damage by denuding the young shoots of their leaves. They become full grown in time to change to chrysalids so that the butterflies may emerge in June. The Silver Crescent Charidryas nycteis While this species has not the broad distribution for wliich the Pearl Crescent is notable it occurs over a large part of the United States. Its distribution is bounded broadly by a line running from southern Canada north of Maine to a point in southern Canada north of Montana, whence it 142 BUTTERFLIES runs south through Wyoming and Utah to the corner of Arizona, and thence east through New Mexico and Texas to Ohio and West Virginia, extending south near the coast to North Carolina. It thus includes a broad belt of terri- tory occupying fully one half of the area of the United States. Throughout this vast area the Silver Crescent is often a purely local species, occurring abundantly during its brief season in some favorable locality but seldom being seen in other places near by. In the north it is single-brooded, the butterflies appearing on the wing during June and commonly disappearing early in July. Late in June the females lay their eggs in clusters of a hundred or less on the under surface of the leaves of various composite plants, notably sunflowers, asters, and a common species of Actinomeris. A week or more later these hatch into little caterpillars that feed together in colonies upon the green tissues of the leaf, taking only the succulent paren- chyma and leaving the network of veins. As one leaf is thus denuded they migrate to another, in this way passing from leaf to leaf for several weeks in summer. They con- tinue to feed until about half grown when they desert the food plant and find shelter at the soil surface. Here they become lethargic and hibernate until the following spring. They then arouse again and feed upon the tender leaves of the new growth, continuing to eat and grow for a few weeks before they become mature as caterpillars and change to chrysalids. A little later the chrysalids disclose the butterflies which as already indicated appear in June. In more southern regions the life-story of the species is not so simple. There is at least a partial second brood and THE TRIBE OF THE CRESCENT-SPOTS 143 it is probable that in many localities the species is both single-brooded and double-brooded. In such a case some of the caterpillars go into hibernation probably about mid- summer, remaining quiescent through the later weeks of summer and all the weeks of fall and winter, while others would mature to chrysalids and butterflies in summer, and the butterflies would lay eggs for a second brood of larvae which would hibernate when partially grown. There are opportunities for careful observers to do good work upon the life-history of this species in many parts of its range. The Pearl Crescent Phyciodes iharos Some years ago Mr. Samuel H. Scudder, the most not- able student of New England butterflies, wrote a delightful essay with the title "Butterflies as Botanists." From his long experience in rearing the eggs of these insects he con- cluded that the egg-laying females know in a most remark- able way the precise kinds of leaves upon which to ovi- posit. He educed many illustrations in proof of the fact and quoted a remark of Asa Gray, the most eminent of American botanists, that is worth repeating. At that time Scudder had reason to believe that the Pearl Crescent laid its eggs exclusively upon the New England aster. Now the asters as a group have been a source of much trouble to the botanists who have attempted to classify them as to species and variety. The various forms are so similar to one another that different authorities have not agreed as to the limitations of the species. So when Gray was told that this little butterfly was able always to distinguish 144 BUTTERFLIES and select for her egg-laying a single species of this vexing tribe he replied: "If your butterfly selects only that, it is a better botanist than most of us." While later observers have found that this beautiful little insect is not so exclusive in its choice of a food plant as was formerly believed, it serves to illustrate the fact that a large proportion of the caterpillars of this group have a very narrow range of food plants. In nearly every case where the food is thus restricted the insect feeds only upon species which are closely related to one another, generally falling within a single genus according to the classification of the botanists. There has been much discussion in regard to the way in which the mother butterfly knows the particular species which she chooses for oviposition. Experiments ap- parently have shown that she is not dependent upon the sense of sight but rather upon the sense of smell, which as is well known is much more highly developed in insects than in the higher animals. I suppose it is not very strange that a creature which has fed from infancy upon leaves with a certain taste and odor should in its later life respond only to that particular odor and should neglect all others. In a way the butterfly itself is a product of the plant and it probably is not necessary to assume that each butterfly differentiates the odors of all kinds of plants but only that she responds to the fragrance of the one with which she has been particularly associated. This idea may suggest to various observers an interest- ing point of view. When you see a butterfly flying leisurely from plant to plant and alighting upon the leaves rather than the blossom, you may be pretty sure that she is bent upon egg-laying. Now watch her to see if she goes at once From a drawing by Mary E. Walker See page 153 THE HOP MERCHANT Caterpillar, chrysalis, ami butterflies. (Reduced) .Moiiriiiiiu-Cloak Sec jhu/c-s //?. 171 .-^ The Viceroy visit iiifj wild carrot flowers See jnujr VJ- EXAMPLES OF FOUR-FOOTED BUTTERFLIES SHOWING USE OF THE FOUR LE(!S (IMH)to hoi, Mini pit by M !■■<■-■ J- li rooks y ■•/ FLASHLIGHT PHOTOGRAPH OF MONARCH OR MILKWEF.I) BUTTFRFLIFS IN MICRATION THREE angle-wings: UPPER SURFACE The American Tortoise-shell {fiee page 182) The Red Admiral {see page 160) The Violet-tij) {see page l'>0) THKEE-AXGLE WINdS: LOWER .SURFACE The American Tortoise-shell (.see page 182) The Red Admiral {see page UiO) The \'iolet-tip {aee page 150) From (I (lidiriiKj h/j ]f'. I. Bcecraft THE PATNTKI) BEAUTY hipillnr, (Oirys.-ili-^, :inil l)iill(M-ny .S'rc luiijc Ui-l THE TRIBE OF THE ANGLE-WINGS 161 it lacks the winged seeds of the latter it is even more effectually protected from the attacks of vertebrate enemies on account of its irritating hairs. At any rate, nettles of various kind are widely distributed over the earth's surface, and consequently it is not surprising that the Nettle Butterfly or Red Admiral should be almost as cosmopolitan as the Thistle butterfly. The two species are closely related in structure and habits and the life-his- tory of the one is very similar to that of the other. About the middle of May one may see in open fields and along sunny highways these Red Admirals flitting from flower to flower, or stopping occasionally upon green leaves in search of opportunities to lay their eggs. Should you observe them closely you might notice that some of them seemed frayed and worn while others seemed per- fectly bright and fresh. {See plates, pages 160-161.) The Life-story Late in May and early in June these butterflies deposit their eggs upon the leaves of the nettles. As a rule only one or a few eggs are laid on a leaf, but when the butter- flies are abundant many leaves upon the plant may be- come infested. About a week later the egg hatches into a larva, which is likely to eat more or less of the empty shell before crawling up the stem of the plant to the un- folding buds at the top. Here it makes its first nest by webbing together the still closed upper surface of a leaf not yet unfolded. It is thus able to furnish itself with protection from weather and enemies, as well as an abund- ant supply of succulent food. It remains in this first home about a week, then it casts its skin, still within its protection, and stays until it has recovered after the 162 BUTTERFLIES process. It now migrates to another larger, expanded leaf where it very cleverly proceeds to construct its second nest. In order to do this it weakens the midrib at the base of the leaf by biting nearly through it. Then it cuts a hole in the blade of the leaf at the base in such a way that the margins are made to droop, so that they can be fast- ened together with silk to form a little tent. We thus have a tent-like nest hanging down from the stem of the leaf on the under side of which the caterpillar will find shelter, while near at hand is the green tissue of the inner surface of the leaf waiting to be eaten. This improvised tent serves as the home during this second stage of the caterpillar. Here also the second moult commonly takes place, after which the caterpillar migrates to a new leaf and constructs its third nest. The rest of the story of the caterpillar's life consists of similar chapters. After each moult a new tent is formed and even the chrysalis is often hung within the last one. The eggs which were laid late in May develop into butterflies during July. These in turn lay eggs for the second brood of caterpillars most of which develop into butterflies late in August or early in September, but some of which apparently remain in the chrysalis stage unchanged throughout the winter, and mature as butter- flies about the middle of the following May. This is the explanation of the fact mentioned at the beginning of this discussion that one can find late in spring and early in summer some butterflies which seem worn and frayed while others seem perfectly fresh. They are all the progeny of the midsummer brood of the previous summer, but some of them have been living as full-grown butterflies through eight long months of tempestuous weather, while THE TRIBE OF THE ANGLE-WINGS 163 others have just been disclosed from the protecting walls of the chrysalis. The world-wide distribution of this butterfly is shown in the statement that it occurs throughout Europe, and in North America from Newfoundland to Cuba and Guatemala. It is a safe guess that it is found in practi- cally all locahties where nettles grow. It is not alone the association between a butterfly cater- pillar and its host plant which has been brought about during the long ages through which one generation has been succeeding another, but there have been also many developments of similar associations between the cater- pillars and their parasitic enemies. The Red Admiral is a good example of such a development. During its long growth as a species it has been exposed to attack by vast numbers of tiny foes which live at the expense of other insects. Several of these foes have found in the bodies of the caterpillars good opportunities for growth, so that now the Red Admiral, as a species, has to reckon with many enemies among these tiny parasites. The inter- action between caterpillar host and uninvited parasitic guest has much to do with the great irregularity in the numbers of the butterflies. It is simply another example of that complicated struggle for existence, by means of which nature keeps ever a fairly even balance of her myriad forces. The Painted Beauty Vanessa huntera One of the most interesting phases of the study of but- terflies is to learn how often they take advantage in their 164 BUTTERFLIES life-history of any peculiarity of the food plant which has a protective value. The Painted Beauty is an excellent illustration of this. The caterpillar feeds upon the leaves of the common Everlasting or Gnaphalium. This is an abundant and widely distributed plant, found along road- sides and in fields and pastures. It is notable for the woolly covering on stems, leaves, and flowers — this dry, hairy surface being so evident that the flowers will ap- parently continue in blossom when they have dried, hence its common name Everlasting or, as the French call a similar flower. Immortelle. {See plates, pages 161, 176.) The utilization of the hairs upon the leaves is begTin by the mother butterfly when she lays her egg upon the upper surface, pushing it down among the hairs so that it is almost concealed. Should you be fortunate enough to find one of these eggs you would see that it is a small, yellowish green object, looking like a tiny barrel with several vertical ribs upon its surface. A few days after the egg is laid it hatches into a minute caterpillar that begins eat- ing off the hairs where they are attached to the leaf, in such a way that it soon has a free space beneath a bunch of these hairs which it has more or less matted together by means of silken thread. The little caterpillar has thus provided for itself a protecting nest that effectually conceals it from birds or other enemies. It now begins feeding upon the succulent surface of the rather thick leaf, where it has removed the hairs. After several days of such feeding it moults, still under the shelter of its hairy covering. This process of moulting and feeding continues for two or three weeks, the caterpillar occasionally making a new covering as needed for its food supply. The later nests are likely to be made by folding two or THE TRIBE OF THE ANGLE-WINGS 165 three leaves together, binding them with silken thread. The caterpillar in doing this takes advantage of the fact that the terminal leaves are vertical before they have spread out, so that it is a comparatively simple matter to make a little house by binding their edges together with silken threads. The larva feeds upon the inner walls of the house it thus constructs, and as it becomes larger the buds and blossoms are also utilized for food. When the caterpillar is full grown it thus finds itself fairly well concealed within a very substantial sort of a home. Many of them have the apparent good sense to realize that this is as safe a place as they are likely to find for shelter during the period of the chrysalis. So the caterpillar makes the nest especially secure near the cen- tre of what might be called the ceil ng and in this web it entangles its hind legs and hangs downward, preparatory to changing to the chrysalis. A few hours later the skin splits apart and is wriggled off, leaving the chrysalis hanging in place of the caterpillar. About a fortnight later the butterfly emerges and crawls at once to the out- side of the nest, where it rests quietly while its wings ex- pand and its tissues harden. Then it flies away in search of the nectar of thistles and many other flowers which it visits freely. This Painted Beauty is a wonderful example of harmo- nious coloring. The general tone of the upper surface of the wings is fulvous, with some distinct white markings on a blackish background at the outer angles of the front pair. There is also more or less blackish shading on the base and margin of all the wings with an indistinct row of about four dots, more or less run together, near the margin of the hind wing. The under surface of the wings is even 166 BUTTERFLIES more beautiful than the upper, and furnishes a striking example of flower-picturing. There is a little fulvous background near the middle of the front wings, but the rest of the surface is spotted and striped with blotches and circles of gray and brown in a most intricate design. On each front wing near the outer angle are three indistinct eye-spots in a row, and on the outer half of each hind wing there are two bull's-eye circles, one smaller than the other, which form the most conspicuous feature in the marking of the insect. When full grown the caterpillars are a little more than an inch long with a general color of velvety black, marked with fine yellow lines and more or less covered with bristly spines. There is also a distinct row of whitish spots along each side beginning a short distance back of the head. This is a widely distributed butterfly, occurring from Canada to the Southern states and beyond. In most northern regions it seems to be two-brooded, the butter- flies commonly hibernating as adults; but sometimes the winter is passed in the condition of the chrysalis. Along its southern range there are three and perhaps four broods each year. The Painted Lady or the Cosmopolite Vanessa cardui Our story of this beautiful butterfly ought really to begin with that of one of the most successful plants in the world. Now a plant is successful from its own point of view when it is able to multiply abundantly in many different sorts of situations and to spread easily over a large area. The THE TRIBE OF THE ANGLE-WINGS 167 plant I have in mind is the thistle, which from time im- memorial has been one of the commonest neighbors of man. It is found over the whole habitable globe, as well as in many parts which are scarcely habitable. It has many advantages in its struggle for life. The roots pene- trate deeply into the soil; the thickened, spiny leaves are so protected by their juices and their spines that they are molested by very few enemies; the flower stalks are also clothed in a similar armature; and the great heads of flowers are surrounded with prickly involucres that gener- ally prevent their being eaten by browsing animals or even by phytophagous insects. The brightly colored blossoms are abundantly provided with nectar and pollen, and they attract great numbers of bees, moths, and butterflies, in order to bring about cross-fertilization. But all of these advantages are of little significance so far as wide dis- tribution is concerned, compared with the feathery seeds which are produced in such abundance and so generally scattered by the slightest breath of wind that the word thistle-down has come into general use to express a lightly moving object. These airy seeds have been riding on the wings of the wind all over the surface of the earth for un- told millions of years. Doubtless during severe storms they may be carried thousands of miles, and it is easy to think that one of them might readily go half-way round the world before it found a resting place. Wherever such a seed alighted and found the condition of a moist soil and slight protection, it would be lils:ely soon to spring into growth and to start anew the development of its ancient race. The thistle, however, has not been entirely unmolested during its aeons of existence. There has been developing 168 BUTTERFLIES along with it one of the most beautiful of our butterflies which has received various scientific names and the com- mon name of the Painted Lady, although it is also often called the Thistle Butterfly and the Cosmopolite, which latter title perhaps is to be preferred. This butterfly, however, can scarcely be considered a troublesome en- emy of its host plant, for it is seldom sufficiently abundant to injure the thistle appreciably. The relation between the two is rather suggestive of that mutual toleration by which two living things develop together with advantage at least to one and without serious disadvantage to the other. The universal distribution of the food plant has led to a like distribution of the butterfly. Consequently the Thistle butterfly has long been recognized as the most cosmopolitan species of its group. (See plate, page 176.) Aside from the wide distribution of its food plant and possibly correlated with it through the diversity of cli- matic conditions under which the insect has developed, this butterfly is remarkable for its powers of flight. Many instances are known where it has been taken at sea long distances from land. This is due not only to the pro- pensity of the individual for taking aerial journeys, but also to the fact that this is one of the butterflies which has the instinct to congregate in swarms and to migrate long distances when thus congregated. In 1879 such a flock started from Africa and migrated to Europe. One of the most remarkable things about this butterfly is our ignorance of what it does with itself in winter. American entomologists are agreed that the adult butter- fly hibernates, but where it does so seems not to be known. Here is an excellent opportunity for some young naturalist to go scouting, hunting in board piles, under THE TRIBE OF THE ANGLE-WINGS 169 loose bark, or with a flashlight searching the interiors of hollow trees to find between November and April living specimens of this butterfly. Such a discovery would be a real service to science and should at once be made known through some scientific journal. In Europe there seems to be a belief that the insect hibernates partially at least in the condition of the chrysalis. The Life-story While we may not know just where the butterflies have been throughout the winter, we do know that in southern New England they begin to be seen in fields and along roadsides about the middle of May. Many of the speci- mens then have a ragged appearance which is a pretty good indication that they came from the chrysalis the fall before and have been lying concealed through all the weeks since. These butterflies lay their small greenish, barrel- shaped eggs on the leaves of the thistle. The mother butterfly chooses the location rather carefully and de- posits only one egg upon a leaf. The butterflies continue thus to visit flowers and to lay eggs until about the middle of June when apparently they perish. About a week after the egg has thus been laid, it hatches into a small spiny caterpiUar which does not take the trouble to devour its egg shell as so many other cater- pillars do. Instead it crawls around to the lower side of the leaf and gnaws off enough of the silken surface of the leaf to furnish material for making a webby covering, the leaf particles being woven together by threads from the caterpillar's mouth. In this way the little creature soon provides itself with a snug enclosure which serves it as a temporary home. It remains in this home much of the 170 BUTTERFLIES time when not eating, going out occasionally to feed upon the green tissues of the adjacent parts of the leaf. This first home of the young caterpillar, made as it is as a flat blanket upon a flat surface, can be used only by a very small larva. Consequently, the caterpillar soon finds these quarters too cramped and it deserts them to make a new home with larger space. This second nest is com- monly made on the upper surface of a leaf, the edges of which are likely to be more or less drawn together and other supports connected from other leaves or a near-by stem. The caterpillar continues to use this nest number two as a place for remaining when not feeding and for protection during the process of moulting. But even this larger nest is likely to be given up about the time the caterpillar becomes half grown, and a third nest is begun in the upper part of the plant. This is likely to be very commodious, its walls being made of leaves or stems bound together by a silken web. Within this the cater- pillar completes its growth, going out and in through one or more doors when it wishes to feed. Sometimes it even re- mains within this nest during the process of changing to the chrysalis, hanging downward from the upper part in much the same way that the caterpillar of the Painted Beauty butterfly does. In case it leaves the nest when fully developed it generally finds a place nearby in which to pupate. About ten days after the caterpillar has changed to a chrysalis it changes again to the adult butterfly. In southern New England these butterflies appear about the middle of July and lay eggs soon afterward, these eggs hatching into butterflies that change to chrysalids and change again to butterflies late in August or early in Sep- THE TRIBE OF THE ANGLE-WINGS 171 tember. This autumn brood doubtless furnishes the butterflies that will be seen upon the wing the following May, so that it is pretty certain that they must find some shelter in which to pass the intervening months. The full-grown caterpillar of the Thistle butterfly is about one and a quarter inches long and of a general yellowish color, more or less marked with blackish as well as with paler lines of color. There are many transverse rows of spines along the segments, each yellowish spine having a circle of smaller ones at the top. Notwithstanding its fondness for thistles, these cater- pillars occasionally feed upon various other plants. One might readily expect them to be able to live upon other composites upon which they are found, but it seems a bit strange that they should be recorded as being "especially fond of mallows." The Mourning-cloak Vanessa antiopa One of the most scholarly students of American in- sects has happily called the butterflies "the frail children of the air." It seems a fitting term for creatures so ethereal that they are readily wafted on the wings of the slightest breeze and so delicate in structure that they are likely to be sadly mutilated by the lightest touch of human hand. Such creatures one would say belong to regions of perpetual summer and have no place in the blizzard -swept winters of our Northern states. Yet if one goes into the snow-clad woods during one of the midwinter thaws one is likely to see in every open glade several dark-colored butterflies flitting from tree to tree, or 172 BUTTERFLIES^ resting with expanded wings in the sunniest spots. These butterflies obviously have endured the coldest weather and If they are to survive until another season must continue to endure still more. This species is commonly called the Mourning-cloak butterfly — not a particularly happy name for so beautiful an insect. In England it has the more suggestive title of Camberwell Beauty, and country boys are said to call it the Yellow Edge butterfly. Its general life-story has already been told on pages 112-115. The caterpillars of the Mourning-cloak butterflies are restricted to comparatively few food plants. In regions where they are not especially abundant, they are likely to be found upon willow, poplar, or elm. In general, as many observations indicate, they are as likely to be found upon any one of these food plants as upon either of the other two; but in certain localities where they become especially abundant it seems that they are more likely to occur upon the elm. On this account they have been called the Spiny Elm caterpillars. There is considerable evidence to show that they prefer the American elm to other species of the genus, although in the case of willow and poplar there seems to be little if any preference as to the species. Miss Caroline G. Soule has seen the butterflies deposit- ing their eggs upon the white and canoe birch, and it has been recorded as feeding in Labrador and Europe upon a species of birch. There is one record of the caterpillars having been found feeding upon the hackberry, and also of their having fed greedily upon the leaves of rose bushes, and still another of their having almost defoliated a pear tree. Linden and nettle are also included in the European hsts of the food plants of this species. {See plates, pages lJf.5, 176.) It is evident, however, that all of these, except the three THE TRIBE OF THE ANGLE-WINGS 173 first named — willow, poplar, and elm — are to be regarded as exceptional cases, and that the normal food of the species is the foliage of a plant belonging to one of these three genera. It has generally been supposed that this species is double-brooded in central and southern New England, the butterflies of the first brood appearing early in July. These are said to deposit eggs which hatch into caterpillars that mature into butterflies early in September. These butterflies live through the winter, laying eggs the follow- ing spring. It is very probable that as far north as southern New Hampshire the species is commonly single-brooded. During one season when the caterpillars were unusually abundant, a very careful watch was kept for the second brood in New Hampshire and Vermont by several com- petent observers. Only one colony of caterpillars was found and this was at Durham in the southern part of New Hampshire near the seacoast. Consequently, it seems safe to conclude that in northern and central New England, at least, a single brood is the rule rather than the exception. This involves the conclusion that the butterflies seen upon the wing early in autumn are the same ones that de- veloped in July, and that these same butterflies remain alive through the winter and imtil, in the following May, they lay their eggs. Thus there is a period of ten months of existence in the butterfly state, an extraordinary length of time for a butterfly to live. To a large extent the butterflies disappear in August, and the question arises as to what becomes of them. Our observations lead to the conclusion that they go into sum- mer quarters similar to those which they seek out for 174 BUTTERFLIES winter shelter. Apparently they fly about for a few days after coming from the chrysalis and then retire to cool woods, where under the side of a log or beneath the loose bark of a dead tree they settle down and to all appearances go to sleep. The instinct to remain quiet is very strong in these butterflies. In taking the accompanying photo- graphs, I found that even shortly after coming from the chrysalis the butterflies when disturbed would fold their wings with the antennae between them, and drawing the legs against the body would lie quietly on their sides for a long time. These same butterflies would also hang down- ward from a limb by the horn- in the hibernating position as shown in plate opposite page 32. In the cooler weather of early autumn, the butterflies come from their retreats and fly about in the sunshine. They are especially likely to be seen along the borders of woods or in open glades. At this time they love the sun- shine, and will settle in a sunny place to bask in it. Going into Winter Quarters When the warm days no longer tempt them abroad, the Mourning-cloaks seek shelter in many sorts of situations — under loose bark, in hollow trees, under culverts and bridges, in woodpiles, in crevices of rocks, or alongside logs lying on the ground. In such retreats they remain until the sunshine of spring again calls them forth. Prof. G. H. Parker's observations indicate that these butterflies are very sensitive to changes of tempera- ture, and he has seen the interesting action of the butter- flies crawling into their hiding places, finding that this takes place each day after they had been sunning them- selves. Thus he writes: THE TRIBE OF THE ANGLE-WINGS 175 "These butterflies remain during cool spring nights in places similar to those in which they hibernate in winter, viz., in openings in stone walls, in old out-houses, in open- ings under the bark of trees, etc. They retire to these places with considerable regularity, so that in the open woods, where dozens of individuals may have been seen flitting about, all may have disappeared a quarter of an hour later. I have watched their retreat with some care. On a clear afternoon in early April I took my stand in a woodland where many Mourning-cloak butterflies were on the wing. They continued actively flying about till approximately four o'clock, when I began to notice a di- minution in their numbers. By a quarter past four not a butterfly was to be seen. During the fifteen minutes from four o'clock on I followed two to their hiding places. One alighted on the front of a fallen tree and without expanding its wings crept immediately into a large crack in the bark. The second settled on a stone fence and crept into a hole between some loose stones. The period during which this occurred was marked not so much by a diminution of light as by a rapid fall of temperature." That the habit of lethargy in cold and of resting upon the bark of trees is practically universal with this species is shown by a statement quoted by H. G. Adams in his book, "Beautiful Butterflies," published in England in 1871. The writer quoted says: "In a wood on the summit of the Drachenfels, when the wind was rather keen, I found num- bers resting on the backs of fallen trees in a state of stupor. They made no attempts to escape and when throwTi into the air their wings barely opened or flapping feebly eased their fall or enabled them to seek repose on the stem of a rotten trunk." 176 BUTTERFLIES Its Rarity in England In many books this species is spoken of by its English name Camberwell Beauty. It is so called because it was first observed in the neighborhood of Camberwell in the county of Surrey, England. It seems that in that country it is a very rare species. This is a bit curious con- sidering the fact that in America it is so extremely abund- ant. In his attractive little book quoted above, Mr. Adams begins the discussion of this species with this statement: "This is the crowning glory of the British butterfly collector's cabinet, and a happy man is he who gets a perfect specimen of an insect which is at once so rare and so beautiful," And later in the same discussion is this further statement concerning the scarcity of the species: "In neither the larva nor the pupa state has the insect been found, we believe, in this country where its appearance occurs, except just here and there a single specimen or two, at long and uncertain intervals. About eighty years ago it was seen in many parts of the kingdom and again in 1819, but not since then although almost every year one or more specimens are taken or seen." A curious fact in regard to the Mourning-cloak, as found in England, is that the border around the wings seems to be much more generally white than it is with us. J. O. Westwood in his book on British butterflies describes the margin as of a white or whitish color and other writers speak of the same fact, Kirby in his "Butterflies and Moths" makes this comparative statement: "The border is whitest in British specimens, and perhaps yellowest in American ones." He speaks of it also as one of the rarest British species. It is sometimes called by the TIIKKK .MORE A\(;LE-WIXGS I pper surfaces at k-ft ; Tiiulcr surfaces at right, sliylilly rciluc-d 'I'lic Hufkeyo {see page 18S) 'rhc Paiuled l?cauly {see page IG-J) 'J'lic Cosiuopolitaii {see page IGiJ) From a drawing by W. I. Beecroft THE MOURNING-CLOAK Caterpillar, chrysalis, and butterfly See pages 112. 171 THE TRIBE OF THE ANGLE-WINGS 177 common name the White Border and also occasionally the Grand Surprise, appellations which bear out what has been said above both in regard to the color of the border and the rarity of the insect. The Mourning-cloaks subsist upon a considerable vari- ety of liquid food which they suck through their long tongues. In spring, when they first come from their winter quarters, they visit the stumps of recently cut trees and suck the exuding sap, a habit which they con- tinue whenever opportunity offers. Mr. W. F. Fiske has noticed that they commonly sip the sap of maple twigs where the squirrels have gnawed the bark. A little later they visit the willow catkins to suck the nectar secreted by these blossoms, and still later they hover about the delicate blossoms of the mayflower, or traihng arbutus, for a similar purpose. Probably many other flowers are thus rifled of their sweets, although this butterfly seems to be a less regular visitor to flowers than are many of its allies. A httle later, when the aphids, or plant-lice, have become sufficiently abundant so that the so-called "honey dew" is to be found upon the infested shrubs, these Mourn- ing-cloaks sometimes sip the liquid sweet from the surface of the leaves. In April and May they occasionally visit the flowers of moose wood, and later in the season have been observed upon the blossoms of the common milk- weed. From the time the early apples ripen these butter- flies may often be seen beneath the orchard trees, sipping the liquids of the fallen and decaying fruit. The Parasites of the Eggs One fine spring morning I came upon a Mourning-cloak depositing a cluster of eggs upon a willow twig. She was 178 BUTTERFLIES so busily engaged that I was able to draw near and watch the operation for some time before she flew away. As soon as she was gone I was much interested to see a tiny parasitic fly running eagerly over the newly laid eggs, and this fly also was so busily interested in her work that I was able to cut the twig ojBF and sit down to observe at leisure through a lens the actions of the insect. I dictated to a companion my notes of these observations and so was able to get rather a complete record of the process of ovi- position. The tiny fly would stop over one of the butterfly eggs, holding its body vertical with the hind legs far back and the other legs so straightened out as to hold the front of the body high up. Then it would insert its tiny ovi- positor through the egg shell and proceed to deposit an egg of its own inside of the larger egg of the butterfly. At least it seemed a safe assumption that this was what happened although of course it was impossible to see the smaller egg at the time. While thus engaged the anten- nae of the tiny fly were bent directly downward to the egg beneath. In about a minute the fly withdrew its ovi- positor and after running around for a few seconds again settled upon another egg and repeated the operation. Then it tried again on a third egg, after which I got out my watch and began timing the process. These are the results in the case of the next dozen eggs that were laid. It required : 94 sec. to lay egg No. 4. Then fly moved around 26 sec. <£ ii (< (< aa << 120 (< ii <( c< ii 5. 83 cc (C (< ii ii 6. 92 rii,g l,y If. /. Bcccrojt See pages 268-282 so.ME co:mmox skippers The Loiif; Dash, male, at top; the Vitellius Skipper, female, next helow; (he i aiiadian skipper resting on iris flower in the middle; the Least Skii)per, next l)eiow: l.<'niiar.l s .^kipper at rest on leaf, next; and the Sachem Skipper, male, at bottom /'/■();;/ (I ilriiiriiKi hi/ IT. I. Beecrnft See [Hit/e.s rJ'i-.'O. THE STA