The BuckeyeJunonia coeniaSome genera of butterflies seem to belong almost exclusively to the north temperate regions, seldom occurring even in our Southern states. Others belong equally exclusivelyto tropical regions, seldom straying into the north. The Buckeye is an illustration of the latter group. The genus Junonia to which it belongs is essentially tropical, as it contains several species which are found throughout the tropics in both the Old and the New Worlds. In fact, this is apparently the only species which occurs north of the tropics. It has an extraordinary range, being found from Cuba to Massachusetts and from the Atlantic to the Pacific coasts. Toward the northern limits of its range it is very rare and one of the greatest prizes which the collector can obtain. In our Southern states it is an abundant and generally distributed butterfly and, as it hibernates as an adult and one group follows another throughout the season rather rapidly, it is likely to be taken at almost any time. (See plate,page 176.)The mother butterflies select as food plants for the larvae various members of either the plantain or figwort families. They lay eggs, one in a place, upon the leaves of plantain, figwort, gerardia, and related plants generally near the tip of the leaves. Less than a week later these hatch into spiny caterpillars which feed upon the green substance of the leaves during the next few weeks. For the most part they eat between the veins leaving a ragged effect which may help in finding them. When full grown they change to chrysalids which hang straight downward and bear a general resemblance to those of the Thistle butterfly. Curiously enough, those chrysalids which are attacked by parasites take on a characteristic golden hue; although the normal healthy chrysalids are dark brown with a few touches of a decidedly lighter brown.In its tropical home, where there is no winter period to interrupt its growth, this butterfly doubtless continues todevelop generation after generation without any break in the sequence. As the species goes north, however, there is necessarily such an interruption—in which case the winter seems commonly to be passed by the adult butterfly. In our Southern states there are commonly three or four broods each year, while in the northern parts of its range there is but one brood a year. In the South there is such an overlapping that all stages of the insect may be found at one time.Synopsis of the Angle-wingsI. The PolygoniasThe most angular of the Angle-wings are grouped in the genus Polygonia. They are characterized by having the outer margin of the front wings projecting in two places in a way to give an angular effect, and by having the hind or inner margin distinctly excised toward the outer end, so that this margin is curved rather than straight.Violet-tip(Polygonia interrogationisorGrapta interrogationis). Expanse 2½ inches. Under surface of each hind wing marked by a silvery semicolon, made up of a dot and a crescent.Hop Merchant(Polygonia commaorGrapta comma). Expanse 2 inches. A white comma with expanded tips on lower surface of each hind wing. Lower surface of all the wings mottled with brown.Green Comma(Polygonia faunusorGrapta faunus). Expanse 2 inches. A white comma with expanded tips on lower surface of each hind wing. The lower surface of all the wings more or less mottled with green toward the margins.Gray Comma(Polygonia progneorGrapta progne). Expanse 2 inches. A white comma with tips narrowed rather than expanded on lower surface of each hind wing.II. The VanessidsOur beautiful species of the genus Vanessa may be known by the long scales that make up the fringe on the wing margins, in alternate groups of black and white. There are also several white spots on the upper surface of the outer angle of each front wing.Red Admiral(Vanessa atalanta,Pyrameis atalantaorCynthia atalanta). Expanse 2 inches. Upper surface of front wings blackish, marked with white spots on outer angle and a broad orange stripe across the middle.Painted Beauty(Vanessa huntera,Pyrameis hunteraorCynthia huntera). Expanse 2½ inches. Upper surface orange-brown with black, white, and blue markings. Lower surface of each hind wing with two large eye-spots, each extending across two veins.Painted LadyorCosmopolite(Vanessa cardui,Pyrameis carduiorCynthia cardui). Expanse 2½ inches. Easily distinguished from the Painted Beauty by the four or more small eye-spots on the lower surface of each hind wing, each eye-spot being included between two veins.III. Other Angle-wingsThe other common Angle-wings are readily distinguished by the following characters:Mourning-cloak(Euvanessa antiopaorVanessa antiopa). Expanse 3½ inches. Easily known by the nearly black wings with creamy white borders.American Tortoise-shell(Aglais milbertiorVanessa milberti).Expanse 1½ inches. One of the smallest of the Angle-wings. Easily known by its small size and the broad orange band extending across the upper surface of all the wings just beyond the middle. Under surface dark mottled gray without distinct white markings.Compton Tortoise(Eugonia j-album,Vanessa j-albumorGrapta j-album). Expanse 3 inches. Best known by the straight line of the inner margin of the front wings and the white j on the under side of each hind wing.The Buckeye(Junonia coeniaorVanessa coenia). Expanse 1¾ inches. Distinguished by the large eye-spots on the upper surface of the wings, one on each front and two on each hind wing. Eyes not hairy.From a drawing by W. I. BeecroftSee pages268-282SOME COMMON SKIPPERSThe Long Dash, male, at top; the Vitellius Skipper, female, next below; the Canadian Skipper resting on iris flower in the middle; the Least Skipper, next below; Leonard's Skipper at rest on leaf, next; and the Sachem Skipper, male, at bottomFrom a drawing by W. I. BeecroftSee pages195-202THE STAGES OF THE VICEROYThe butterfly freshly emerged; caterpillar hung up for pupation; the chrysalis; the caterpillar feedingTHE TRIBE OF THE SOVEREIGNSNo other small group of American butterflies has attracted so much attention as the species of the genus Basilarchia, which have been happily called the tribe of Sovereigns. These are rather large butterflies with rounded wings which are found in one species or another over practically the whole of North America. Some of them are of exceeding beauty and all of them present life-histories of extraordinary interest. At least two of the species are the most notable examples of the mimicry of other butterflies that are shown in our fauna. They also present some extremely interesting problems for the study of natural hybrids and they illustrate in their development some of the most wonderful cases of adaptation to environment that have ever been found.These butterflies may be considered from so many interesting points of view that it is a bit difficult to know which phases to emphasize. In general, there is a striking similarity in their structure and habits in the earlier stages. The eggs are very nearly alike; the caterpillars resemble one another so closely that even expert entomologists sometimes have to decide what species a collected caterpillar belongs to by seeing what plant it is feeding upon, and the chrysalids are also very similar.Some of the more interesting phases in the development of these insects are discussed in connection with the life-stories of the different species. A phase which is characteristic to all of them may well be emphasized here. From the time the caterpillars hatch until they change to chrysalids they illustrate to a marked degree an adaptation through structure and habit which must very largely protect them from attack by birds and other enemies. Their structure and markings are almost grotesque. The body is covered with strange club-like appendages and it is colored with a curious mottling of tones of green, drab, brown, and white which is very difficult to describe but which suggests, as the caterpillar rests upon rough bark, simply a bit of bird dung or some natural excrescence. The caterpillars have the habit of feeding at night and remaining upon their perches by day, often assuming positions which are very unusual among insect larvae. Such positions, in which they remain motionless for hours at a time, are undoubtedly of protective value and help to conceal the insect. After the caterpillars are half grown they rest not upon the leaves upon which they feed, but rather upon the bark of twigs or branches where their peculiar structure is likely to make them inconspicuous.The chrysalids of the Sovereigns are also curiouslymottled in color tones that will probably lead to theirbeingoverlooked.Three distinct species of Sovereigns are found in eastern North America, namely:The Viceroy,Basilarchia archippus.The Banded Purple,Basilarchia arthemis.The Red-spotted Purple,Basilarchia astyanax.The first species, the Viceroy, has a much wider distribution than either of the others. It apparently is found in nearly all localities in which either of these occur, and so includes within its range almost the whole of the United States and much of Canada.The second of these, the Banded Purple, is a northern form. It is found commonly at least as far north as the Mackenzie River region in British America and southward to central Massachusetts. It also occurs as far west as Nebraska so that it has a very wide distribution in northern regions. It is especially abundant in Canada and the White Mountains.The third, the Red-spotted Purple, is the characteristic form south of latitude 42 degrees. Its range overlaps that of the Banded Purple for about one degree but it is seldom found north of latitude 42 degrees. It seems to range about as far west as the Banded Purple.There are several other butterflies belonging to this genus which are rarely found and which occur only in certain limited regions. There has been much discussion in regard to these. Some entomologists have thought them simply varieties or dimorphic forms while others have considered them hybrids. An analysis of the conditions shows that these doubtful butterflies occur only in regions where the different species overlap. Thus inthe boundary connecting the Banded Purple and the Red-spotted Purple there are forms which resemble these two species in such a way as to suggest that these are the parents of the hybrid. In localities where the Viceroy and the Banded Purple occur there are other forms which seem to connect these two species, and in the locality where the Viceroy and the Red-spotted Purple occur there are still other forms which seem to suggest these as the parents. So the evidence seems pretty conclusive that where these butterflies overlap there are likely to be occasional crosses between the species which result in these natural hybrids.In the far Western states there are certain other species of Basilarchia which take the place of the eastern form. One of the most abundant of these on the Pacific Coast is sometimes called Lorquin's Admiral (B. lorquini). In Florida there is another species,B. floridensis, which is found in the Southern states. It is the only one whose coloring resembles that of the Viceroy.The ViceroyBasilarchia archippusThe common name of this butterfly was probably given it in allusion to its resemblance to the Monarch butterfly. For the Monarch and the Viceroy have been closely associated in the minds of many observers ever since people began to study butterflies in America. These two insects have become famous as the most notable examples that we have of the mimicking of one butterfly by another. According to the theory which has been held by many naturalists, the Monarch is distasteful to birds and other animalsand it advertises the fact by its bright combination of brown and black. The Monarch is thus an example of what has often been called warning coloration. On the other hand, the Viceroy is commonly supposed to have no objectionable taste when eaten by birds, but it so closely resembles the Monarch in its color pattern and its habits of flight that it has been assumed that birds would not touch it because of its resemblance to the distasteful butterfly. There has, however, recently been a reaction among naturalists in regard to the validity of many supposed examples of warning coloration and the whole subject is still open to careful investigation. (Seecover; and plate,page 145.)Whether the Viceroy deserves its celebrity as an insect mimic or not, it is well worthy of study for other reasons. It is a common and attractive butterfly and it has most interesting habits in the larval state. It is found over a large part of North America and flies freely from spring until autumn over meadows, fields, and open glades.The Yearly Cycle of LifeTo trace the yearly cycle of this butterfly's life, let us begin with one of the mother insects flitting along a stream in early summer. She stops now and then to lay an egg on the tip of a leaf on a willow or poplar. She then continues on her way occasionally sipping nectar from any early flowers she may chance to find, and continuing her leisurely life perhaps for several weeks.The egg thus laid upon the poplar leaf remains in position for a week or more, unless it should be devoured by some wandering ant or discovered by some tiny parasite. If it escapes these dangers, it hatches into a minute caterpillarthat escapes from the egg shell through a hole in its side. After it has come out it turns around and eats the remainder of the shell. It then begins feeding upon the tender tissue of the leaf it is resting upon, nibbling at the sides until its appetite is satisfied. Then it retires to the midrib on the lower surface where it remains quietly through the day and thereafter feeds chiefly at night. After about a week it becomes too large for the skin with which it was born, so it moults and immediately devours its cast skin. It continues these operations of feeding and moulting at occasional intervals for several weeks, finally becoming a rather large and curious looking caterpillar, mottled in greenish olive and light gray, with two large horn-like projections from the front of the body.It finally becomes full grown in this larval state. Then it spins a web of silk upon the bark of the twig and entangles the hooked claws of its hind legs in the silken web. It thus hangs downward until the larval skin is shuffled off and the curious pupa with the conspicuous hump upon the middle of its back remains in its place. This chrysalis is of a mottled coloring, very similar to that of the caterpillar. A week or so later the chrysalis skin breaks open, and the butterfly comes out, catching hold of the twig with its legs and hanging quietly in position while its wings expand.The butterflies of this brood are likely to appear late in summer. It is the second brood of adult butterflies for the season. These insects have the same leisurely habits as those that were on the wing earlier in the season. In a similar way the mother butterflies lay their eggs on the leaves of willows and poplars, and these eggs soon hatch into young caterpillars that look like those that hatched inearly summer. The caterpillars, however, of this autumnal brood have a most interesting habit which was entirely lacking in those of early summer. Soon after hatching they begin to make for themselves little houses in which to pass the winter. This is very cleverly done by utilizing part of the leaf upon which they are feeding. Each side of the leaf toward its tip is eaten off with the midrib remaining untouched; then the lower half of the leaf which has not been eaten is rolled into a tube and securely sewed together with silken threads. The stem of the leaf is also covered with a similar silken web and securely fastened to the twig in such a way that it is impossible for the leaf to fall off when the other leaves do. The little caterpillar thus cleverly provides itself with a safe winter home into which it retreats on the approach of cold weather to remain until spring. They enter these little cases head first, and apparently seldom emerge again until the warm spring sun brings them forth to feed upon the developing willow catkins or the unfolding leaves.The caterpillars that thus pass the winter in these pitcher-like cases are perhaps a third grown. They develop rapidly in spring and are likely to use the cases for resting purposes when they are not feeding. After a few weeks they become full-grown caterpillars and change to chrysalids, to change again a little later into the butterflies that appear in early summer. There are thus two broods of each stage of the insect during the year.Curious Caterpillar HabitsThis brief summary of the yearly history of the Viceroy is by no means adequate as a story of the many interesting things to be told about this insect, which has been carefullystudied by several eminent naturalists. One of these is the strange habit the very young caterpillars have of fastening a few bits of leaf together by means of silken threads and then tying the bunch to the denuded rib of the leaf. To explain this, allow me to quote from an admirable essay of the late Samuel H. Scudder, whose studies of butterflies have added so much to our knowledge of these beautiful creatures:"Soon after birth," wrote Mr. Scudder, "when it has eaten but a very few swaths down the leaf, the little fellow constructs a small and loose packet from minute bits of leaf and other rejectamenta, loosely fastened to one another and to the midrib, close to but scarcely touching the eaten edge of the leaf; and as fast as the leaf is eaten, it removes this packet (continually added to until it becomes almost as big as a small pea) farther and farther down the midrib away from its perch, always keeping it near the eaten edge. It should be noted that it is so loosely attached (the bits of leaf at all possible angles) that it is moved by the least breath. Meanwhile, the caterpillar has been growing larger and more conspicuous, and thus in greater peril from its enemies. There are two possible services that this odd packet may render. A spider wandering over a leaf and observing its motion may seize it, and thinking it has a prize, hurry away with it and leave its architect unharmed. This seems to me rather a strained suggestion, for a wandering spider would probably proceed to investigate it on the spot. Another explanation seems more probable. It should be remembered that the leaves preferred by these creatures as food are mostly such as are easily shaken by the wind, and as the caterpillar moves with the leaf and with all the surroundingleaves (in a continual fluttering in the case of the trembling aspen, and to a less degree in the other food plants), this of itself is a protection to it, as it would more readily escape observation as an object distinct from the leaves, all being in motion together; but on the more stable leaves, like the willow, the motion in a feeble wind would not be sufficient to be serviceable, and here, at least, the packet comes into play. An object in motion among others at rest is a noticeable thing; a fact well recognized among animals, as a host of them show when they fear being seen. This packet attached by loose silken threads moves, as stated, with a breath of wind, and so would distract attention from its architect near by, who has taken pains to place it at the farthest remove from his perch while still (to avoid undesirable steps) on his daily track. If this be really its object, it is surely one of the oddest devices in nature."The curious winter cases of the Viceroy were first carefully described by the late Dr. C. V. Riley, in one of his classic reports on the insects of Missouri. It is one of the best accounts which has ever been written and is well worth quoting at some length:"The larvae of the autumnal brood," wrote Doctor Riley, "when about one fourth or one third grown, build for themselves curious little houses in which they pass the winter. First and foremost—with wise forethought and being well aware through its natural instincts that the leaf which it has collected for its house will fall to the ground when the cold weather sets in unless it takes measures to prevent this—the larva fastens the stem of the leaf with silken cables securely to the twig from which it grows. It then gnaws off the blade of the leaf at its tipend, leaving little else but the midrib. Finally it rolls the remaining part of the blade of the leaf into a cylinder, sewing the edges together with silk. The basal portion of the cylinder is of course tapered to a point as the edges of the leaf are nearly drawn together, not overlapped; and invariably the lower side of the leaf forms the outside of the house so as to have the projecting midrib out of the way of the larva as it reposes snugly on the inside. The whole, when finished, has somewhat the appearance of the leaf of a miniature pitcher-plant (Sarracenia), its length being .50-.65 inch, and its diameter .11-.14 inch."These curious little cases may be commonly found upon our willows and poplars in the winter time. I have examined hundreds of them and although they are invariably built upon this plan, they vary greatly in the degree of perfection which the architect attained; and this is especially the case where they have been built in confinement. The blade on the tip piece is sometimes gnawed off right down to the rib; at others it is left almost as broad as the tube. Sometimes it is bent over the orifice; at others not. They are also much more irregular and ungainly when made with broad leaves, such as those of the silver poplar, than when made from the more narrow leaves of the willow tree. These autumnal larvae have also another peculiar habit: they exhibit a tendency to build from the time they are hatched and will always eat the leaves from the side, gnawing large holes and cutting along the sides of the midrib. They commence at the tip, and as they work downward toward the base, they collect the débris into a little bunch which they fasten with silk to the midrib. When the hibernaculum is finished the seam is perfectly smooth and the hole inside is lined withsilk. The larva, having completed its work, composes itself for the winter with the hind end toward the orifice. Here it remains till the catkins are in bloom the next spring when it retreats from its house and commences feeding. Not the least wonderful part of this phenomenon is that it is only the autumnal brood of larvae that form pitcher-like houses to live in during the inclement season of the year—the summer brood having no occasion to shelter themselves from cold." It is an interesting fact that in most northern regions these winter cases are nearly always made so near the ground that they are protected by snow during most of the winter.When an insect has such a curious habit as that of making these winter cases it seems comparatively easy to explain it as an acquired instinct brought about through the conditions of life during the long period in which successive generations have been laid. But, as Doctor Riley seems to suggest above, it is much more difficult to explain this sort of phenomenon when it occurs only in one of two or more broods during the season.The Banded PurpleBasilarchia arthemisNone of our common butterflies shows more striking color markings than the Banded Purple. A broad white stripe runs midway through the wings on both surfaces, the white making a strong contrast to the purplish or brownish black of the rest of the wings. This white band is supplemented by rows of fulvous and of blue dots, especially on both surfaces of the hind wings.This butterfly is a northern form ranging to a large extent north of the regions occupied by the Viceroy. Its life-history is very similar to that of the latter insect. The caterpillars have the same curious habits and bear a close general resemblance to one another. The Banded Purple butterflies appear in June and lay their eggs in July upon the tips of the leaves of birches, especially the black birch. Almost all of these eggs are laid within two or three feet of the ground. They are of grayish green color. The caterpillars are greenish- or olive-brown.About a week after the egg is laid it hatches into a small caterpillar that feeds upon the sides of the leaf and rests upon the midrib just as the Viceroy caterpillar does. It continues to feed through July and the early part of August, moulting once or twice before it begins to form the winter case. It usually goes into this during the latter part of August, when it is in the second or third caterpillar stage. From then on it remains quietly in its winter home, being covered by the deep snows during several months, and coming out about the middle of the following May, when the spring warmth starts the buds of its food plant. It then feeds for two or three weeks before it changes to a chrysalis to emerge in June as a butterfly. There seems to be normally but one brood each year although under exceptional conditions some of the eggs laid in July mature into butterflies the same season. But it is probable that these butterflies either do not lay eggs and perish as the cold comes on, or that if they do lay eggs the caterpillars that hatch from them do not get large enough to construct their winter cases. Consequently, it is doubtful if we can consider the insect really two-brooded even in part.The Red-spotted PurpleBasilarchia astyanaxWere it not for the wonderful iridescence of its wings the Red-spotted Purple would be one of the most plainly marked of the Sovereigns. But the upper surface of both pairs of wings is thickly covered with iridescent scales which give the insect a shimmering beauty that makes it conspicuous among northern butterflies, suggesting something of the marvelous coloring of the large tropical species. The general coloring is a purplish black with rows of white dots along the borders of the wings. The under surface shows much more of the fulvous brown which is so characteristic of the Viceroy, the brownish background being rather thinly overlaid with iridescent scales, but with a large number of spots and stripes, where the fulvous color alone shows.The favorite food plants of this species belong to the great orderRosaceaewhich includes the apple, pear, cherry, rose, and many other common trees and shrubs. The egg is laid upon the extreme tip of the leaf, a characteristic habit of all the species of Basilarchia. It obviously must have decided advantages in preserving the eggs from attack by ants, spiders, Ichneumon flies, and other enemies. All of these creatures are constantly patrolling leaf surfaces in search of eggs and minute insects. They are much more likely to find their victims upon the broad general surface than upon the extreme tip of narrowly pointed leaves. The eggs of all these butterflies are small, and pitted much like a tiny little honeycomb with a large number of tiny hairs arising from the surface. Thesehairs are very similar to the hairs upon the surface of many leaves and they probably assist in leading other insects to overlook the eggs. Yet, notwithstanding these devices for protection, it remains true that a large proportion of the eggs are attacked by tiny parasites and probably many others are eaten by ants and spiders. This very fact emphasizes the necessity of such protective features as the laying of one egg in a place upon the tip of a leaf and the hairy covering on the egg shells.A few days after the eggs are laid each hatches into a small caterpillar that immediately begins feeding upon the green tissues beside it—first, however, devouring the empty egg shell. It does not eat the midrib of the leaf, but utilizes it as a perch, generally winding it more or less with silken threads, apparently to make it stronger and to prevent it from curling up. The caterpillar seems to feed chiefly at night, resting quietly by day. After a week or so it moults and then continues feeding as before. It continues to feed and grow for several weeks, moulting regularly until it becomes full fed as a caterpillar. It then spins a web of silk closely upon the bark of twig or branch or possibly upon some other object near at hand. In this web it entangles the hooked claws of its hind legs and hangs downward preparatory to the change to the chrysalis. Soon afterward the last larval skin is shed and the chrysalis hangs in place of the caterpillar. This chrysalis has the characteristic form of all the members of this limited group, the outer skin being well hardened and there being a very prominent projection on the middle of the back.The chrysalis hangs thus, buffeted more or less bywind and rain for about ten days, then the skin breaks apart and the butterfly emerges.Over a large part of its range there are two broods of this butterfly each year. The adults appear in early summer and lay eggs which develop into butterflies again during the latter part of summer. The life-history of this generation is the one described in the last paragraph. The eggs laid by these late summer butterflies, however, require a somewhat different story. They hatch in the same way as the others but when the caterpillars have moulted about twice they form a winter case or hibernaculum, in exactly the same way as the caterpillars of the Viceroy. They remain within these winter homes till the following spring, when they come forth and complete their development producing the early summer brood of butterflies with which our story began.The VicereineBasilarchia floridensisIn Florida and some of the other Southern states there is a butterfly which looks almost like the Viceroy except that the brown coloring of the wings is very much darker. The species has been called the Vicereine as it is believed to mimic the Queen Butterfly, a species closely related to the Monarch and occurring in the Southern states. The Vicereine probably has a life-history very similar to that of its northern cousin.Synopsis of the SovereignsBanded Purple(Basilarchia arthemisorLimenitis arthemis). Expanse 2½ inches. Ground color of uppersurface of wings black with a distinct white band in bow-like form running across the middle of both wings. A row of six tawny spots just outside the white band on each hind wing and various sub-marginal blue spots outside of these. Under surface tawny brown with the white stripe distinct and many red-brown spots.Red-spotted Purple(Basilarchia astyanaxorLimenitis astyanax). Expanse 2½ inches. Ground color brownish black tinged with bluish, especially on the hind wings. No white band but various red and blue spots, especially near the outer margins of the upper surface of both pairs of wings.Viceroy(Basilarchia archippusorLimenitis disippus). Expanse 2½ inches. General color reddish brown with veins and margins blackish. A narrow black band running across the hind wings just beyond the middle. A series of white spots in all the marginal bands.Vicereine(Basilarchia floridensis). Expanse 2½ inches. Similar to the Viceroy but much darker in the brown coloring of all the wings.THE TRIBE OF THE EMPERORSThe members of this small group are distinguished from the closely related Sovereigns by the tailed hind wings in one species, by the eye-spots on the upper surface of the wings of the others, and by the fact that on the club of the antennae there are three instead of four longitudinal ridges. There is also a distinction in the arrangement of the veins of the hind wings.This tribe is represented in our northern fauna by only two genera. In the genus Chlorippe the antennae are as long as the front wings are wide. In the genus Anoea theantennae are much shorter than the width of the front wings. Only two species of the former and one of the latter are sufficiently abundant to be considered here.The Goatweed EmperorAnoea andriaComparatively few butterflies are confined so closely to the valley of the Mississippi River as the Goatweed Emperor. From southern Illinois south to the Gulf this insect is rather abundant in many localities where its food plant, the goatweed, is common. The life-history of the insect was carefully studied by Dr. C. V. Riley, and one of the best accounts was published in one of his early reports on the insects of Missouri. The excellent illustrations in that article first made the species familiar to many students.Briefly summarized, the life-history runs something like this: the butterflies hibernate, coming forth in spring and visiting various spring and early summer flowers. The females deposit eggs singly upon the leaves of the young goatweed plants. In a week or less each egg hatches into a little caterpillar that feeds upon the tip of the leaf leaving the midrib and covering it with silk so that it may serve as a resting perch. Later each makes an excellent tent for itself by bending over and binding together the opposite margins of a leaf.[D]This bit of work is cleverly done, a hole being left at each end so that there is good ventilation and an opportunity for the caterpillar to go in and out. Quite frequently the nest is also lined with more or less silken webbing. This tent is used as a refuge from the heat of the sun and doubtless serves also in concealing the caterpillar from its many enemies. The larva goes out to neighboring leaves when it wishes to feed and only occasionally eats up the leaf of which its tent is made. When this is done it must of course construct another home.[D]Seenext page.THE BANDED PURPLE (seepage 202)THE RED-SPOTTED PURPLE (seepage 204)THE BLUE-EYED GRAYLING OR COMMON WOOD-NYMPH(Upper and lower surface) (seepage 215)From drawings by W. I. BeecroftSee pages207-214THREE EMPEROR BUTTERFLIESThe Gray Emperor, female (top)The Tawny Emperor, female (middle)The Goatweed Emperor, female (bottom)After some weeks of this sheltered existence the caterpillar is ready to change to a chrysalis. It leaves the tent and commonly attaches a bit of silken web to the under side of a leaf or branch of its food plant or some other kind of shelter. Here it changes to a chrysalis, to emerge a little later as the beautiful burnt-orange butterfly. There are said to be two broods each season, in some regions, although in others there seems to be but one. The butterflies hibernate in hollow trees or in such other shelters as they may find.Goatweed Butterfly:a, larva;b, chrysalis;c, larval case. (After Riley)The full-grown caterpillar (a) is an inch and a half long and of a general grayish color, dotted thickly with slightly elevated points. The chrysalis (b) is suggestive of thatof the Monarch butterfly. It is light green covered with whitish granules.The adult butterfly is remarkable for the falcate shape of the outer margin of each front wing and the broad tail at the hind outer angle of each hind wing. In the male the upper surface of all the wings is of a dark orange tone, with a rather narrow brown marginal marking. In the female this marginal band is broader and is nearly paralleled by another narrower band a little nearer the body. In bright sunshine there is a distinct purplish red iridescence over practically the whole upper surface. The under side of both wings is of a color to suggest a dead brown leaf, with a purplish iridescence in certain angles of light.The Gray EmperorChlorippe celtisThis very distinctive medium-sized butterfly is found in the Southern states at least as far west as the Mississippi Valley. It extends north to Indiana and Ohio and probably occurs quite generally from Ohio eastward. This species is distinguished by the general gray-brown or olive-brown coloring of the wing surfaces, heavily marked with a much darker dusky brown and with many irregular white spots as well as one large eye-spot on each front wing near the border, and a row of seven more or less distinct eye-spots near the border of each hind wing.Like the Tawny Emperor this species feeds in the larval state upon the leaves of hackberry. In Missouri the butterflies appear in June. A little later they lay eggs upon the under side of the hackberry leaves, commonlyone in a place but sometimes several side by side. A few days later these eggs hatch into little yellow caterpillars that feed upon the leaves for about a month when they become full grown. They are then a little more than an inch long, of a general light green color with yellow spots along the middle of the back and three yellow lines along each side. The head has a pair of curious antlers much like those of the caterpillar of the Tawny Emperor. These caterpillars now spin a bit of silken web on the under side of the leaf or twig. They attach their hind legs into this web and hang downward for a day or two, before casting the last larval skin and changing to chrysalids. They change again to butterflies which are seen upon the wing early in August. These butterflies lay eggs in turn on the hackberry leaves, the eggs soon hatching into small caterpillars which according to Riley's observations are less active than those of the earlier brood. These caterpillars feed for a few weeks until they become nearly half grown and have passed their second or possibly their third moult. They now stop eating and get ready for a long fast through the winter. Apparently some of them at least attach themselves to the under side of the hackberry leaves and turn to a brownish color, remaining upon the leaves until the latter fall to the ground and presumably hibernating in the shelter thus provided. Whether or not all of the caterpillars have this rather curious habit seems to be doubtful. It has been suggested that some of them find shelter within the crevices in the rough bark of the tree. At any rate, the caterpillars remain in a sort of stupor until the following spring. Then they awaken, climb up the trees or bushes, and begin feeding upon the young leaves. They continue this until they become fullgrown in May when they change to chrysalids, to emerge as the first brood of butterflies the following month. Many of the caterpillars make a sort of nest for themselves by spinning a web of silk upon the under surface of the leaf and drawing together slightly the outer edges.As is the case with so many other butterflies that hibernate as caterpillars, apparently the species is only partially double-brooded. Some of the earlier caterpillars become lethargic when half grown and remain in that condition throughout the later weeks of summer and all through the fall and winter.The Tawny EmperorChlorippe clytonThis handsome butterfly is easily distinguished from the Gray Emperor by the general reddish color of the wings which are thickly marked with bands and eye-spots of darker brown or black. The eye-spots are especially marked on the hind wing, there being a row of five of these on each hind wing in both sexes. The females are decidedly larger than the male and generally of a distinctly lighter color.This butterfly is a southern species found more or less abundantly from southern New York to northern Florida and across the country to a line drawn from Iowa to Texas. It seems to be more common in the Mississippi Valley than in other regions and its life-history was first thoroughly worked out in Missouri and published in one of Riley's classic reports on the insects of that state. It has since been studied by Edwards and others, but even now thereseems to be some uncertainty in regard to many points in its development, notably the number of broods in different localities and the habits of the larvae when preparing for hibernation.The principal points in the life-history of the species may be outlined as follows: some time in July the eggs are laid on the leaves of hackberry in dense clusters, each of which may contain from two hundred to five hundred eggs. These are usually deposited in two or more layers, one upon another. A little more than a week later these eggs hatch, each caterpillar eating through one end in a way to cut out the rim of a tiny cap which is pushed up as the larva escapes. The whole brood emerges at practically the same time and collects upon one or more leaves where they begin to feed upon the succulent green tissues. Like so many caterpillars that feed in companies each spins a silken thread wherever it goes.The little larvae remain together until after the third moult, at which time they are about half grown. In the more northern regions where they are found they are now likely to scatter about in search of quarters for hibernation. Having found suitable shelter, they remain through the winter to come forth early the following spring and feed upon the developing leaves of the hackberry trees. They continue to do this for a few weeks before they become full grown. They are then smooth-bodied, greenish worms about an inch and a half long, striped longitudinally in yellow and brown. The hind end of the body is forked in a curious fashion and the head is even more remarkable for the strange pair of tiny antlers projecting from it.These full-grown caterpillars soon change to pale green chrysalids, lightly striped with longitudinal lines of yellow,with a distinctly pointed head. From these chrysalids butterflies emerge early in summer.Evidently in the more Southern states there are two broods of these butterflies each year but there is great need of more precise knowledge in regard to them.As is the case with so many other butterflies there is a dimorphic form, calledocellata, in which the outer half of the hind wing is very dark brown, with the eye-spot showing as black with red-brown circles.
The BuckeyeJunonia coenia
Some genera of butterflies seem to belong almost exclusively to the north temperate regions, seldom occurring even in our Southern states. Others belong equally exclusivelyto tropical regions, seldom straying into the north. The Buckeye is an illustration of the latter group. The genus Junonia to which it belongs is essentially tropical, as it contains several species which are found throughout the tropics in both the Old and the New Worlds. In fact, this is apparently the only species which occurs north of the tropics. It has an extraordinary range, being found from Cuba to Massachusetts and from the Atlantic to the Pacific coasts. Toward the northern limits of its range it is very rare and one of the greatest prizes which the collector can obtain. In our Southern states it is an abundant and generally distributed butterfly and, as it hibernates as an adult and one group follows another throughout the season rather rapidly, it is likely to be taken at almost any time. (See plate,page 176.)
The mother butterflies select as food plants for the larvae various members of either the plantain or figwort families. They lay eggs, one in a place, upon the leaves of plantain, figwort, gerardia, and related plants generally near the tip of the leaves. Less than a week later these hatch into spiny caterpillars which feed upon the green substance of the leaves during the next few weeks. For the most part they eat between the veins leaving a ragged effect which may help in finding them. When full grown they change to chrysalids which hang straight downward and bear a general resemblance to those of the Thistle butterfly. Curiously enough, those chrysalids which are attacked by parasites take on a characteristic golden hue; although the normal healthy chrysalids are dark brown with a few touches of a decidedly lighter brown.
In its tropical home, where there is no winter period to interrupt its growth, this butterfly doubtless continues todevelop generation after generation without any break in the sequence. As the species goes north, however, there is necessarily such an interruption—in which case the winter seems commonly to be passed by the adult butterfly. In our Southern states there are commonly three or four broods each year, while in the northern parts of its range there is but one brood a year. In the South there is such an overlapping that all stages of the insect may be found at one time.
Synopsis of the Angle-wings
I. The Polygonias
The most angular of the Angle-wings are grouped in the genus Polygonia. They are characterized by having the outer margin of the front wings projecting in two places in a way to give an angular effect, and by having the hind or inner margin distinctly excised toward the outer end, so that this margin is curved rather than straight.
Violet-tip(Polygonia interrogationisorGrapta interrogationis). Expanse 2½ inches. Under surface of each hind wing marked by a silvery semicolon, made up of a dot and a crescent.
Hop Merchant(Polygonia commaorGrapta comma). Expanse 2 inches. A white comma with expanded tips on lower surface of each hind wing. Lower surface of all the wings mottled with brown.
Green Comma(Polygonia faunusorGrapta faunus). Expanse 2 inches. A white comma with expanded tips on lower surface of each hind wing. The lower surface of all the wings more or less mottled with green toward the margins.
Gray Comma(Polygonia progneorGrapta progne). Expanse 2 inches. A white comma with tips narrowed rather than expanded on lower surface of each hind wing.
II. The Vanessids
Our beautiful species of the genus Vanessa may be known by the long scales that make up the fringe on the wing margins, in alternate groups of black and white. There are also several white spots on the upper surface of the outer angle of each front wing.
Red Admiral(Vanessa atalanta,Pyrameis atalantaorCynthia atalanta). Expanse 2 inches. Upper surface of front wings blackish, marked with white spots on outer angle and a broad orange stripe across the middle.
Painted Beauty(Vanessa huntera,Pyrameis hunteraorCynthia huntera). Expanse 2½ inches. Upper surface orange-brown with black, white, and blue markings. Lower surface of each hind wing with two large eye-spots, each extending across two veins.
Painted LadyorCosmopolite(Vanessa cardui,Pyrameis carduiorCynthia cardui). Expanse 2½ inches. Easily distinguished from the Painted Beauty by the four or more small eye-spots on the lower surface of each hind wing, each eye-spot being included between two veins.
III. Other Angle-wings
The other common Angle-wings are readily distinguished by the following characters:
Mourning-cloak(Euvanessa antiopaorVanessa antiopa). Expanse 3½ inches. Easily known by the nearly black wings with creamy white borders.
American Tortoise-shell(Aglais milbertiorVanessa milberti).Expanse 1½ inches. One of the smallest of the Angle-wings. Easily known by its small size and the broad orange band extending across the upper surface of all the wings just beyond the middle. Under surface dark mottled gray without distinct white markings.
Compton Tortoise(Eugonia j-album,Vanessa j-albumorGrapta j-album). Expanse 3 inches. Best known by the straight line of the inner margin of the front wings and the white j on the under side of each hind wing.
The Buckeye(Junonia coeniaorVanessa coenia). Expanse 1¾ inches. Distinguished by the large eye-spots on the upper surface of the wings, one on each front and two on each hind wing. Eyes not hairy.
From a drawing by W. I. BeecroftSee pages268-282SOME COMMON SKIPPERSThe Long Dash, male, at top; the Vitellius Skipper, female, next below; the Canadian Skipper resting on iris flower in the middle; the Least Skipper, next below; Leonard's Skipper at rest on leaf, next; and the Sachem Skipper, male, at bottom
From a drawing by W. I. BeecroftSee pages268-282SOME COMMON SKIPPERSThe Long Dash, male, at top; the Vitellius Skipper, female, next below; the Canadian Skipper resting on iris flower in the middle; the Least Skipper, next below; Leonard's Skipper at rest on leaf, next; and the Sachem Skipper, male, at bottom
From a drawing by W. I. Beecroft
See pages268-282
The Long Dash, male, at top; the Vitellius Skipper, female, next below; the Canadian Skipper resting on iris flower in the middle; the Least Skipper, next below; Leonard's Skipper at rest on leaf, next; and the Sachem Skipper, male, at bottom
From a drawing by W. I. BeecroftSee pages195-202THE STAGES OF THE VICEROYThe butterfly freshly emerged; caterpillar hung up for pupation; the chrysalis; the caterpillar feeding
From a drawing by W. I. BeecroftSee pages195-202THE STAGES OF THE VICEROYThe butterfly freshly emerged; caterpillar hung up for pupation; the chrysalis; the caterpillar feeding
From a drawing by W. I. Beecroft
See pages195-202
THE TRIBE OF THE SOVEREIGNS
No other small group of American butterflies has attracted so much attention as the species of the genus Basilarchia, which have been happily called the tribe of Sovereigns. These are rather large butterflies with rounded wings which are found in one species or another over practically the whole of North America. Some of them are of exceeding beauty and all of them present life-histories of extraordinary interest. At least two of the species are the most notable examples of the mimicry of other butterflies that are shown in our fauna. They also present some extremely interesting problems for the study of natural hybrids and they illustrate in their development some of the most wonderful cases of adaptation to environment that have ever been found.
These butterflies may be considered from so many interesting points of view that it is a bit difficult to know which phases to emphasize. In general, there is a striking similarity in their structure and habits in the earlier stages. The eggs are very nearly alike; the caterpillars resemble one another so closely that even expert entomologists sometimes have to decide what species a collected caterpillar belongs to by seeing what plant it is feeding upon, and the chrysalids are also very similar.
Some of the more interesting phases in the development of these insects are discussed in connection with the life-stories of the different species. A phase which is characteristic to all of them may well be emphasized here. From the time the caterpillars hatch until they change to chrysalids they illustrate to a marked degree an adaptation through structure and habit which must very largely protect them from attack by birds and other enemies. Their structure and markings are almost grotesque. The body is covered with strange club-like appendages and it is colored with a curious mottling of tones of green, drab, brown, and white which is very difficult to describe but which suggests, as the caterpillar rests upon rough bark, simply a bit of bird dung or some natural excrescence. The caterpillars have the habit of feeding at night and remaining upon their perches by day, often assuming positions which are very unusual among insect larvae. Such positions, in which they remain motionless for hours at a time, are undoubtedly of protective value and help to conceal the insect. After the caterpillars are half grown they rest not upon the leaves upon which they feed, but rather upon the bark of twigs or branches where their peculiar structure is likely to make them inconspicuous.
The chrysalids of the Sovereigns are also curiouslymottled in color tones that will probably lead to theirbeingoverlooked.
Three distinct species of Sovereigns are found in eastern North America, namely:
The Viceroy,Basilarchia archippus.
The Banded Purple,Basilarchia arthemis.
The Red-spotted Purple,Basilarchia astyanax.
The first species, the Viceroy, has a much wider distribution than either of the others. It apparently is found in nearly all localities in which either of these occur, and so includes within its range almost the whole of the United States and much of Canada.
The second of these, the Banded Purple, is a northern form. It is found commonly at least as far north as the Mackenzie River region in British America and southward to central Massachusetts. It also occurs as far west as Nebraska so that it has a very wide distribution in northern regions. It is especially abundant in Canada and the White Mountains.
The third, the Red-spotted Purple, is the characteristic form south of latitude 42 degrees. Its range overlaps that of the Banded Purple for about one degree but it is seldom found north of latitude 42 degrees. It seems to range about as far west as the Banded Purple.
There are several other butterflies belonging to this genus which are rarely found and which occur only in certain limited regions. There has been much discussion in regard to these. Some entomologists have thought them simply varieties or dimorphic forms while others have considered them hybrids. An analysis of the conditions shows that these doubtful butterflies occur only in regions where the different species overlap. Thus inthe boundary connecting the Banded Purple and the Red-spotted Purple there are forms which resemble these two species in such a way as to suggest that these are the parents of the hybrid. In localities where the Viceroy and the Banded Purple occur there are other forms which seem to connect these two species, and in the locality where the Viceroy and the Red-spotted Purple occur there are still other forms which seem to suggest these as the parents. So the evidence seems pretty conclusive that where these butterflies overlap there are likely to be occasional crosses between the species which result in these natural hybrids.
In the far Western states there are certain other species of Basilarchia which take the place of the eastern form. One of the most abundant of these on the Pacific Coast is sometimes called Lorquin's Admiral (B. lorquini). In Florida there is another species,B. floridensis, which is found in the Southern states. It is the only one whose coloring resembles that of the Viceroy.
The ViceroyBasilarchia archippus
The common name of this butterfly was probably given it in allusion to its resemblance to the Monarch butterfly. For the Monarch and the Viceroy have been closely associated in the minds of many observers ever since people began to study butterflies in America. These two insects have become famous as the most notable examples that we have of the mimicking of one butterfly by another. According to the theory which has been held by many naturalists, the Monarch is distasteful to birds and other animalsand it advertises the fact by its bright combination of brown and black. The Monarch is thus an example of what has often been called warning coloration. On the other hand, the Viceroy is commonly supposed to have no objectionable taste when eaten by birds, but it so closely resembles the Monarch in its color pattern and its habits of flight that it has been assumed that birds would not touch it because of its resemblance to the distasteful butterfly. There has, however, recently been a reaction among naturalists in regard to the validity of many supposed examples of warning coloration and the whole subject is still open to careful investigation. (Seecover; and plate,page 145.)
Whether the Viceroy deserves its celebrity as an insect mimic or not, it is well worthy of study for other reasons. It is a common and attractive butterfly and it has most interesting habits in the larval state. It is found over a large part of North America and flies freely from spring until autumn over meadows, fields, and open glades.
The Yearly Cycle of Life
To trace the yearly cycle of this butterfly's life, let us begin with one of the mother insects flitting along a stream in early summer. She stops now and then to lay an egg on the tip of a leaf on a willow or poplar. She then continues on her way occasionally sipping nectar from any early flowers she may chance to find, and continuing her leisurely life perhaps for several weeks.
The egg thus laid upon the poplar leaf remains in position for a week or more, unless it should be devoured by some wandering ant or discovered by some tiny parasite. If it escapes these dangers, it hatches into a minute caterpillarthat escapes from the egg shell through a hole in its side. After it has come out it turns around and eats the remainder of the shell. It then begins feeding upon the tender tissue of the leaf it is resting upon, nibbling at the sides until its appetite is satisfied. Then it retires to the midrib on the lower surface where it remains quietly through the day and thereafter feeds chiefly at night. After about a week it becomes too large for the skin with which it was born, so it moults and immediately devours its cast skin. It continues these operations of feeding and moulting at occasional intervals for several weeks, finally becoming a rather large and curious looking caterpillar, mottled in greenish olive and light gray, with two large horn-like projections from the front of the body.
It finally becomes full grown in this larval state. Then it spins a web of silk upon the bark of the twig and entangles the hooked claws of its hind legs in the silken web. It thus hangs downward until the larval skin is shuffled off and the curious pupa with the conspicuous hump upon the middle of its back remains in its place. This chrysalis is of a mottled coloring, very similar to that of the caterpillar. A week or so later the chrysalis skin breaks open, and the butterfly comes out, catching hold of the twig with its legs and hanging quietly in position while its wings expand.
The butterflies of this brood are likely to appear late in summer. It is the second brood of adult butterflies for the season. These insects have the same leisurely habits as those that were on the wing earlier in the season. In a similar way the mother butterflies lay their eggs on the leaves of willows and poplars, and these eggs soon hatch into young caterpillars that look like those that hatched inearly summer. The caterpillars, however, of this autumnal brood have a most interesting habit which was entirely lacking in those of early summer. Soon after hatching they begin to make for themselves little houses in which to pass the winter. This is very cleverly done by utilizing part of the leaf upon which they are feeding. Each side of the leaf toward its tip is eaten off with the midrib remaining untouched; then the lower half of the leaf which has not been eaten is rolled into a tube and securely sewed together with silken threads. The stem of the leaf is also covered with a similar silken web and securely fastened to the twig in such a way that it is impossible for the leaf to fall off when the other leaves do. The little caterpillar thus cleverly provides itself with a safe winter home into which it retreats on the approach of cold weather to remain until spring. They enter these little cases head first, and apparently seldom emerge again until the warm spring sun brings them forth to feed upon the developing willow catkins or the unfolding leaves.
The caterpillars that thus pass the winter in these pitcher-like cases are perhaps a third grown. They develop rapidly in spring and are likely to use the cases for resting purposes when they are not feeding. After a few weeks they become full-grown caterpillars and change to chrysalids, to change again a little later into the butterflies that appear in early summer. There are thus two broods of each stage of the insect during the year.
Curious Caterpillar Habits
This brief summary of the yearly history of the Viceroy is by no means adequate as a story of the many interesting things to be told about this insect, which has been carefullystudied by several eminent naturalists. One of these is the strange habit the very young caterpillars have of fastening a few bits of leaf together by means of silken threads and then tying the bunch to the denuded rib of the leaf. To explain this, allow me to quote from an admirable essay of the late Samuel H. Scudder, whose studies of butterflies have added so much to our knowledge of these beautiful creatures:
"Soon after birth," wrote Mr. Scudder, "when it has eaten but a very few swaths down the leaf, the little fellow constructs a small and loose packet from minute bits of leaf and other rejectamenta, loosely fastened to one another and to the midrib, close to but scarcely touching the eaten edge of the leaf; and as fast as the leaf is eaten, it removes this packet (continually added to until it becomes almost as big as a small pea) farther and farther down the midrib away from its perch, always keeping it near the eaten edge. It should be noted that it is so loosely attached (the bits of leaf at all possible angles) that it is moved by the least breath. Meanwhile, the caterpillar has been growing larger and more conspicuous, and thus in greater peril from its enemies. There are two possible services that this odd packet may render. A spider wandering over a leaf and observing its motion may seize it, and thinking it has a prize, hurry away with it and leave its architect unharmed. This seems to me rather a strained suggestion, for a wandering spider would probably proceed to investigate it on the spot. Another explanation seems more probable. It should be remembered that the leaves preferred by these creatures as food are mostly such as are easily shaken by the wind, and as the caterpillar moves with the leaf and with all the surroundingleaves (in a continual fluttering in the case of the trembling aspen, and to a less degree in the other food plants), this of itself is a protection to it, as it would more readily escape observation as an object distinct from the leaves, all being in motion together; but on the more stable leaves, like the willow, the motion in a feeble wind would not be sufficient to be serviceable, and here, at least, the packet comes into play. An object in motion among others at rest is a noticeable thing; a fact well recognized among animals, as a host of them show when they fear being seen. This packet attached by loose silken threads moves, as stated, with a breath of wind, and so would distract attention from its architect near by, who has taken pains to place it at the farthest remove from his perch while still (to avoid undesirable steps) on his daily track. If this be really its object, it is surely one of the oddest devices in nature."
The curious winter cases of the Viceroy were first carefully described by the late Dr. C. V. Riley, in one of his classic reports on the insects of Missouri. It is one of the best accounts which has ever been written and is well worth quoting at some length:
"The larvae of the autumnal brood," wrote Doctor Riley, "when about one fourth or one third grown, build for themselves curious little houses in which they pass the winter. First and foremost—with wise forethought and being well aware through its natural instincts that the leaf which it has collected for its house will fall to the ground when the cold weather sets in unless it takes measures to prevent this—the larva fastens the stem of the leaf with silken cables securely to the twig from which it grows. It then gnaws off the blade of the leaf at its tipend, leaving little else but the midrib. Finally it rolls the remaining part of the blade of the leaf into a cylinder, sewing the edges together with silk. The basal portion of the cylinder is of course tapered to a point as the edges of the leaf are nearly drawn together, not overlapped; and invariably the lower side of the leaf forms the outside of the house so as to have the projecting midrib out of the way of the larva as it reposes snugly on the inside. The whole, when finished, has somewhat the appearance of the leaf of a miniature pitcher-plant (Sarracenia), its length being .50-.65 inch, and its diameter .11-.14 inch.
"These curious little cases may be commonly found upon our willows and poplars in the winter time. I have examined hundreds of them and although they are invariably built upon this plan, they vary greatly in the degree of perfection which the architect attained; and this is especially the case where they have been built in confinement. The blade on the tip piece is sometimes gnawed off right down to the rib; at others it is left almost as broad as the tube. Sometimes it is bent over the orifice; at others not. They are also much more irregular and ungainly when made with broad leaves, such as those of the silver poplar, than when made from the more narrow leaves of the willow tree. These autumnal larvae have also another peculiar habit: they exhibit a tendency to build from the time they are hatched and will always eat the leaves from the side, gnawing large holes and cutting along the sides of the midrib. They commence at the tip, and as they work downward toward the base, they collect the débris into a little bunch which they fasten with silk to the midrib. When the hibernaculum is finished the seam is perfectly smooth and the hole inside is lined withsilk. The larva, having completed its work, composes itself for the winter with the hind end toward the orifice. Here it remains till the catkins are in bloom the next spring when it retreats from its house and commences feeding. Not the least wonderful part of this phenomenon is that it is only the autumnal brood of larvae that form pitcher-like houses to live in during the inclement season of the year—the summer brood having no occasion to shelter themselves from cold." It is an interesting fact that in most northern regions these winter cases are nearly always made so near the ground that they are protected by snow during most of the winter.
When an insect has such a curious habit as that of making these winter cases it seems comparatively easy to explain it as an acquired instinct brought about through the conditions of life during the long period in which successive generations have been laid. But, as Doctor Riley seems to suggest above, it is much more difficult to explain this sort of phenomenon when it occurs only in one of two or more broods during the season.
The Banded PurpleBasilarchia arthemis
None of our common butterflies shows more striking color markings than the Banded Purple. A broad white stripe runs midway through the wings on both surfaces, the white making a strong contrast to the purplish or brownish black of the rest of the wings. This white band is supplemented by rows of fulvous and of blue dots, especially on both surfaces of the hind wings.
This butterfly is a northern form ranging to a large extent north of the regions occupied by the Viceroy. Its life-history is very similar to that of the latter insect. The caterpillars have the same curious habits and bear a close general resemblance to one another. The Banded Purple butterflies appear in June and lay their eggs in July upon the tips of the leaves of birches, especially the black birch. Almost all of these eggs are laid within two or three feet of the ground. They are of grayish green color. The caterpillars are greenish- or olive-brown.
About a week after the egg is laid it hatches into a small caterpillar that feeds upon the sides of the leaf and rests upon the midrib just as the Viceroy caterpillar does. It continues to feed through July and the early part of August, moulting once or twice before it begins to form the winter case. It usually goes into this during the latter part of August, when it is in the second or third caterpillar stage. From then on it remains quietly in its winter home, being covered by the deep snows during several months, and coming out about the middle of the following May, when the spring warmth starts the buds of its food plant. It then feeds for two or three weeks before it changes to a chrysalis to emerge in June as a butterfly. There seems to be normally but one brood each year although under exceptional conditions some of the eggs laid in July mature into butterflies the same season. But it is probable that these butterflies either do not lay eggs and perish as the cold comes on, or that if they do lay eggs the caterpillars that hatch from them do not get large enough to construct their winter cases. Consequently, it is doubtful if we can consider the insect really two-brooded even in part.
The Red-spotted PurpleBasilarchia astyanax
Were it not for the wonderful iridescence of its wings the Red-spotted Purple would be one of the most plainly marked of the Sovereigns. But the upper surface of both pairs of wings is thickly covered with iridescent scales which give the insect a shimmering beauty that makes it conspicuous among northern butterflies, suggesting something of the marvelous coloring of the large tropical species. The general coloring is a purplish black with rows of white dots along the borders of the wings. The under surface shows much more of the fulvous brown which is so characteristic of the Viceroy, the brownish background being rather thinly overlaid with iridescent scales, but with a large number of spots and stripes, where the fulvous color alone shows.
The favorite food plants of this species belong to the great orderRosaceaewhich includes the apple, pear, cherry, rose, and many other common trees and shrubs. The egg is laid upon the extreme tip of the leaf, a characteristic habit of all the species of Basilarchia. It obviously must have decided advantages in preserving the eggs from attack by ants, spiders, Ichneumon flies, and other enemies. All of these creatures are constantly patrolling leaf surfaces in search of eggs and minute insects. They are much more likely to find their victims upon the broad general surface than upon the extreme tip of narrowly pointed leaves. The eggs of all these butterflies are small, and pitted much like a tiny little honeycomb with a large number of tiny hairs arising from the surface. Thesehairs are very similar to the hairs upon the surface of many leaves and they probably assist in leading other insects to overlook the eggs. Yet, notwithstanding these devices for protection, it remains true that a large proportion of the eggs are attacked by tiny parasites and probably many others are eaten by ants and spiders. This very fact emphasizes the necessity of such protective features as the laying of one egg in a place upon the tip of a leaf and the hairy covering on the egg shells.
A few days after the eggs are laid each hatches into a small caterpillar that immediately begins feeding upon the green tissues beside it—first, however, devouring the empty egg shell. It does not eat the midrib of the leaf, but utilizes it as a perch, generally winding it more or less with silken threads, apparently to make it stronger and to prevent it from curling up. The caterpillar seems to feed chiefly at night, resting quietly by day. After a week or so it moults and then continues feeding as before. It continues to feed and grow for several weeks, moulting regularly until it becomes full fed as a caterpillar. It then spins a web of silk closely upon the bark of twig or branch or possibly upon some other object near at hand. In this web it entangles the hooked claws of its hind legs and hangs downward preparatory to the change to the chrysalis. Soon afterward the last larval skin is shed and the chrysalis hangs in place of the caterpillar. This chrysalis has the characteristic form of all the members of this limited group, the outer skin being well hardened and there being a very prominent projection on the middle of the back.
The chrysalis hangs thus, buffeted more or less bywind and rain for about ten days, then the skin breaks apart and the butterfly emerges.
Over a large part of its range there are two broods of this butterfly each year. The adults appear in early summer and lay eggs which develop into butterflies again during the latter part of summer. The life-history of this generation is the one described in the last paragraph. The eggs laid by these late summer butterflies, however, require a somewhat different story. They hatch in the same way as the others but when the caterpillars have moulted about twice they form a winter case or hibernaculum, in exactly the same way as the caterpillars of the Viceroy. They remain within these winter homes till the following spring, when they come forth and complete their development producing the early summer brood of butterflies with which our story began.
The VicereineBasilarchia floridensis
In Florida and some of the other Southern states there is a butterfly which looks almost like the Viceroy except that the brown coloring of the wings is very much darker. The species has been called the Vicereine as it is believed to mimic the Queen Butterfly, a species closely related to the Monarch and occurring in the Southern states. The Vicereine probably has a life-history very similar to that of its northern cousin.
Synopsis of the Sovereigns
Banded Purple(Basilarchia arthemisorLimenitis arthemis). Expanse 2½ inches. Ground color of uppersurface of wings black with a distinct white band in bow-like form running across the middle of both wings. A row of six tawny spots just outside the white band on each hind wing and various sub-marginal blue spots outside of these. Under surface tawny brown with the white stripe distinct and many red-brown spots.
Red-spotted Purple(Basilarchia astyanaxorLimenitis astyanax). Expanse 2½ inches. Ground color brownish black tinged with bluish, especially on the hind wings. No white band but various red and blue spots, especially near the outer margins of the upper surface of both pairs of wings.
Viceroy(Basilarchia archippusorLimenitis disippus). Expanse 2½ inches. General color reddish brown with veins and margins blackish. A narrow black band running across the hind wings just beyond the middle. A series of white spots in all the marginal bands.
Vicereine(Basilarchia floridensis). Expanse 2½ inches. Similar to the Viceroy but much darker in the brown coloring of all the wings.
THE TRIBE OF THE EMPERORS
The members of this small group are distinguished from the closely related Sovereigns by the tailed hind wings in one species, by the eye-spots on the upper surface of the wings of the others, and by the fact that on the club of the antennae there are three instead of four longitudinal ridges. There is also a distinction in the arrangement of the veins of the hind wings.
This tribe is represented in our northern fauna by only two genera. In the genus Chlorippe the antennae are as long as the front wings are wide. In the genus Anoea theantennae are much shorter than the width of the front wings. Only two species of the former and one of the latter are sufficiently abundant to be considered here.
The Goatweed EmperorAnoea andria
Comparatively few butterflies are confined so closely to the valley of the Mississippi River as the Goatweed Emperor. From southern Illinois south to the Gulf this insect is rather abundant in many localities where its food plant, the goatweed, is common. The life-history of the insect was carefully studied by Dr. C. V. Riley, and one of the best accounts was published in one of his early reports on the insects of Missouri. The excellent illustrations in that article first made the species familiar to many students.
Briefly summarized, the life-history runs something like this: the butterflies hibernate, coming forth in spring and visiting various spring and early summer flowers. The females deposit eggs singly upon the leaves of the young goatweed plants. In a week or less each egg hatches into a little caterpillar that feeds upon the tip of the leaf leaving the midrib and covering it with silk so that it may serve as a resting perch. Later each makes an excellent tent for itself by bending over and binding together the opposite margins of a leaf.[D]This bit of work is cleverly done, a hole being left at each end so that there is good ventilation and an opportunity for the caterpillar to go in and out. Quite frequently the nest is also lined with more or less silken webbing. This tent is used as a refuge from the heat of the sun and doubtless serves also in concealing the caterpillar from its many enemies. The larva goes out to neighboring leaves when it wishes to feed and only occasionally eats up the leaf of which its tent is made. When this is done it must of course construct another home.
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THE BANDED PURPLE (seepage 202)THE RED-SPOTTED PURPLE (seepage 204)THE BLUE-EYED GRAYLING OR COMMON WOOD-NYMPH(Upper and lower surface) (seepage 215)
THE BANDED PURPLE (seepage 202)THE RED-SPOTTED PURPLE (seepage 204)THE BLUE-EYED GRAYLING OR COMMON WOOD-NYMPH(Upper and lower surface) (seepage 215)
From drawings by W. I. BeecroftSee pages207-214THREE EMPEROR BUTTERFLIESThe Gray Emperor, female (top)The Tawny Emperor, female (middle)The Goatweed Emperor, female (bottom)
From drawings by W. I. BeecroftSee pages207-214THREE EMPEROR BUTTERFLIESThe Gray Emperor, female (top)The Tawny Emperor, female (middle)The Goatweed Emperor, female (bottom)
From drawings by W. I. Beecroft
See pages207-214
After some weeks of this sheltered existence the caterpillar is ready to change to a chrysalis. It leaves the tent and commonly attaches a bit of silken web to the under side of a leaf or branch of its food plant or some other kind of shelter. Here it changes to a chrysalis, to emerge a little later as the beautiful burnt-orange butterfly. There are said to be two broods each season, in some regions, although in others there seems to be but one. The butterflies hibernate in hollow trees or in such other shelters as they may find.
Goatweed Butterfly:a, larva;b, chrysalis;c, larval case. (After Riley)
The full-grown caterpillar (a) is an inch and a half long and of a general grayish color, dotted thickly with slightly elevated points. The chrysalis (b) is suggestive of thatof the Monarch butterfly. It is light green covered with whitish granules.
The adult butterfly is remarkable for the falcate shape of the outer margin of each front wing and the broad tail at the hind outer angle of each hind wing. In the male the upper surface of all the wings is of a dark orange tone, with a rather narrow brown marginal marking. In the female this marginal band is broader and is nearly paralleled by another narrower band a little nearer the body. In bright sunshine there is a distinct purplish red iridescence over practically the whole upper surface. The under side of both wings is of a color to suggest a dead brown leaf, with a purplish iridescence in certain angles of light.
The Gray EmperorChlorippe celtis
This very distinctive medium-sized butterfly is found in the Southern states at least as far west as the Mississippi Valley. It extends north to Indiana and Ohio and probably occurs quite generally from Ohio eastward. This species is distinguished by the general gray-brown or olive-brown coloring of the wing surfaces, heavily marked with a much darker dusky brown and with many irregular white spots as well as one large eye-spot on each front wing near the border, and a row of seven more or less distinct eye-spots near the border of each hind wing.
Like the Tawny Emperor this species feeds in the larval state upon the leaves of hackberry. In Missouri the butterflies appear in June. A little later they lay eggs upon the under side of the hackberry leaves, commonlyone in a place but sometimes several side by side. A few days later these eggs hatch into little yellow caterpillars that feed upon the leaves for about a month when they become full grown. They are then a little more than an inch long, of a general light green color with yellow spots along the middle of the back and three yellow lines along each side. The head has a pair of curious antlers much like those of the caterpillar of the Tawny Emperor. These caterpillars now spin a bit of silken web on the under side of the leaf or twig. They attach their hind legs into this web and hang downward for a day or two, before casting the last larval skin and changing to chrysalids. They change again to butterflies which are seen upon the wing early in August. These butterflies lay eggs in turn on the hackberry leaves, the eggs soon hatching into small caterpillars which according to Riley's observations are less active than those of the earlier brood. These caterpillars feed for a few weeks until they become nearly half grown and have passed their second or possibly their third moult. They now stop eating and get ready for a long fast through the winter. Apparently some of them at least attach themselves to the under side of the hackberry leaves and turn to a brownish color, remaining upon the leaves until the latter fall to the ground and presumably hibernating in the shelter thus provided. Whether or not all of the caterpillars have this rather curious habit seems to be doubtful. It has been suggested that some of them find shelter within the crevices in the rough bark of the tree. At any rate, the caterpillars remain in a sort of stupor until the following spring. Then they awaken, climb up the trees or bushes, and begin feeding upon the young leaves. They continue this until they become fullgrown in May when they change to chrysalids, to emerge as the first brood of butterflies the following month. Many of the caterpillars make a sort of nest for themselves by spinning a web of silk upon the under surface of the leaf and drawing together slightly the outer edges.
As is the case with so many other butterflies that hibernate as caterpillars, apparently the species is only partially double-brooded. Some of the earlier caterpillars become lethargic when half grown and remain in that condition throughout the later weeks of summer and all through the fall and winter.
The Tawny EmperorChlorippe clyton
This handsome butterfly is easily distinguished from the Gray Emperor by the general reddish color of the wings which are thickly marked with bands and eye-spots of darker brown or black. The eye-spots are especially marked on the hind wing, there being a row of five of these on each hind wing in both sexes. The females are decidedly larger than the male and generally of a distinctly lighter color.
This butterfly is a southern species found more or less abundantly from southern New York to northern Florida and across the country to a line drawn from Iowa to Texas. It seems to be more common in the Mississippi Valley than in other regions and its life-history was first thoroughly worked out in Missouri and published in one of Riley's classic reports on the insects of that state. It has since been studied by Edwards and others, but even now thereseems to be some uncertainty in regard to many points in its development, notably the number of broods in different localities and the habits of the larvae when preparing for hibernation.
The principal points in the life-history of the species may be outlined as follows: some time in July the eggs are laid on the leaves of hackberry in dense clusters, each of which may contain from two hundred to five hundred eggs. These are usually deposited in two or more layers, one upon another. A little more than a week later these eggs hatch, each caterpillar eating through one end in a way to cut out the rim of a tiny cap which is pushed up as the larva escapes. The whole brood emerges at practically the same time and collects upon one or more leaves where they begin to feed upon the succulent green tissues. Like so many caterpillars that feed in companies each spins a silken thread wherever it goes.
The little larvae remain together until after the third moult, at which time they are about half grown. In the more northern regions where they are found they are now likely to scatter about in search of quarters for hibernation. Having found suitable shelter, they remain through the winter to come forth early the following spring and feed upon the developing leaves of the hackberry trees. They continue to do this for a few weeks before they become full grown. They are then smooth-bodied, greenish worms about an inch and a half long, striped longitudinally in yellow and brown. The hind end of the body is forked in a curious fashion and the head is even more remarkable for the strange pair of tiny antlers projecting from it.
These full-grown caterpillars soon change to pale green chrysalids, lightly striped with longitudinal lines of yellow,with a distinctly pointed head. From these chrysalids butterflies emerge early in summer.
Evidently in the more Southern states there are two broods of these butterflies each year but there is great need of more precise knowledge in regard to them.
As is the case with so many other butterflies there is a dimorphic form, calledocellata, in which the outer half of the hind wing is very dark brown, with the eye-spot showing as black with red-brown circles.