FAMILY I

NYMPHALIDÆ (THE BRUSH-FOOTED BUTTERFLIES)

The family of the Nymphalidæ is composed of butterflies which are of medium and large size, though a few of the genera are made up of species which are quite small. They may be distinguished from all other butterflies by the fact that the first pair of legs in both sexes is atrophied or greatly reduced in size, so that they cannot be used in walking, but are carried folded up upon the breast. The fore feet, except in the case of the female of the snout-butterflies (Libytheinæ), are without tarsal claws, and hence the name "Brush-footed Butterflies" has been applied to them. As the anterior pair of legs is apparently useless, they have been called "The Four-footed Butterflies," which is scientifically a misnomer.

Egg.—The eggs of the Nymphalidæ, for the most part, are dome-shaped or globular, and are marked with raised longitudinal lines extending from the summit toward the base over the entire surface or over the upper portion of the egg. Between these elevations are often found finer and less elevated cross-lines. In a few genera the surface of the eggs is covered with reticulation arranged in geometrical patterns (see Fig. 1).

Caterpillar.—The caterpillars of the Nymphalidæ, as they emerge from the egg, have heads the diameter of which is larger than that of the body, and covered with a number of wart-like elevations from which hairs arise. The body of the immature larva generally tapers from before backward (see Plate III, Figs. 7 and 11). The mature larva is cylindrical in form, sometimes, as in the Satyrinæ, thicker in the middle. Often one or more of the segments are greatly swollen in whole or in part. The larvæ are generally ornamented with fleshy projections or branching spines.

Chrysalids.—The chrysalids are for the most part angular, and often have strongly marked projections. As a rule, they hang with the head downward, having the cremaster, or anal hook, attached to a button of silk woven to the under surface of a limb of a tree, a stone, or some other projecting surface. A few boreal species construct loose coverings of threads of silk at the roots of grasses, and here undergo their transformations. The chrysalids are frequently ornamented with golden or silvery spots.

This is the largest of all the families of butterflies, and it is also the most widely distributed. It is represented by species which have their abode in the cold regions of the far North and upon the lofty summits of mountains, where summer reigns for but a few weeks during the year; and it is enormously developed in equatorial lands, including here some of the most gloriously colored species in the butterfly world. But although these insects appear to have attained their most superb development in the tropics, they are more numerous in the temperate regions than other butterflies, and a certain fearlessness, and fondness for the haunts of men, which seems to characterize some of them, has brought them more under the eyes of observers. The literature of poetry and prose which takes account of the life of the butterfly has mainly dealt with forms belonging to this great assemblage of species.

In the classification of the brush-footed butterflies various subdivisions have been suggested by learned authors, but the species found in the United States and the countries lying northward upon the continent may be all included in the following six groups, or subfamilies:

1. The Euplœinœ, the Euplœids.
2. The Ithomiinœ, the Ithomiids.
3. The Heliconiinœ, the Heliconians.
4. The Nymphalinœ, the Nymphs.
5. The Satyrinœ, the Satyrs.
6. The Libytheinœ, the Snout-butterflies.

The insects belonging to these different subfamilies may be distinguished by the help of the following analytical table, which is based upon that of Professor Comstock, given in his "Manual for the Study of Insects" (p. 396), which in turn is based upon that of Dr. Scudder, in "The Butterflies of New England" (vol. i, p. 115).

Key to the subfamilies of the Nymphalidæ of the United States and Canada

We now proceed to present the various genera and species of this family which occur within the territorial limits of which this book treats. The reader will do well to accompany the study of the descriptions, which are at most mere sketches, by a careful examination of the figures in the plates. In this way a very clear idea of the different species can in most instances be obtained. But with the study of the book should always go, if possible, the study of the living things themselves. Knowledge of nature founded upon books is at best second-hand. To the fields and the woods, then, net in hand! Splendid as may be the sight of a great collection of butterflies from all parts of the world, their wings

"Gleaming with purple and gold,"

no vision is so exquisite and so inspiring as that which greets the true aurelian as in shady dell or upon sun-lit upland, with the blue sky above him and the flowers all around him, he pursues his pleasant, self-imposed tasks, drinking in health at every step.

SUBFAMILY EUPLŒINÆ (THE MILKWEED
BUTTERFLIES)

"Lazily flying Over the flower-decked prairies, West; Basking in sunshine till daylight is dying, And resting all night on Asclepias' breast; Joyously dancing, Merrily prancing, Chasing his lady-love high in the air, Fluttering gaily, Frolicking daily, Free from anxiety, sorrow, and care!"

C.V. Riley.

Butterfly.—Large butterflies; head large; the antennæ inserted on the summit, stout, naked, that is to say, not covered with scales, the club long and not broad; palpi stout; the thorax somewhat compressed, with the top arched. The abdomen is moderately stout, bearing on the eighth segment, on either side, in the case of the male, clasps which are quite conspicuous. The fore wings are greatly produced at the apex and more or less excavated about the middle of the outer border; the hind wings are rounded and generally much smaller than the fore wings; the outer margin is regular, without tails, and the inner margin is sometimes channeled so as to enfold the abdomen. The fore legs are greatly atrophied in the male, less so in the female; these atrophied legs are not provided with claws, but on the other legs the claws are well developed.

Egg.—The eggs are ovate conical, broadly flattened at the base and slightly truncated at the top, with many longitudinal ribs and transverse cross-ridges (see Fig. 4).

[Plate VII.]

Caterpillar.—On emerging from the chrysalis the head is not larger than the body; the body has a few scattered hairs on each segment. On reaching maturity the head is small, the body large, cylindrical, without hair, and conspicuously banded with dark stripes upon a lighter ground, and on some of the segments there are generally erect fleshy processes of considerable length (see Fig. 16). The caterpillars feed upon different species of the milkweed (Asclepias).

Chrysalis.—The chrysalis is relatively short and thick, rounded, with very few projections, tapers very rapidly over the posterior part of the abdomen, and is suspended by a long cremaster from a button of silk (see Fig. 24). The chrysalis is frequently ornamented with golden or silver spots.

This subfamily reaches its largest development in the tropical regions of Asia. Only one genus is represented in our fauna, the genus Anosia.

Genus ANOSIA, Hübner

Butterfly.—Large-sized butterflies; fore wings long, greatly produced at the apex, having a triangular outline, the outer margin approximately as long as the inner margin; the costal border is regularly bowed; the outer border is slightly excavated, the outer angle rounded; the hind wings are well rounded, the costal border projecting just at the base, the inner margin likewise projecting at the base and depressed so as to form a channel clasping the abdomen. On the edge of the first median nervule of the male, about its middle, there is a scent-pouch covered with scales.

[a]Fig. 78.]—Neuration of the genus Anosia.

Egg.—The egg is ovate conical, ribbed perpendicularly with many raised cross-lines between the ridges. The eggs are pale green in color.

Caterpillar.—The caterpillar is cylindrical, fleshy, transversely wrinkled, and has on the second thoracic and eighth abdominal segment pairs of very long and slender fleshy filaments; the body is ornamented by dark bands upon a greenish-yellow ground-color; the filaments are black.

Chrysalis.—The chrysalis is stout, cylindrical, rapidly tapering on the abdomen, and is suspended from a button of silk by a long cremaster. The color of the chrysalis is pale green, ornamented with golden spots.

The larvæ of the genus Anosia feed for the most part upon the varieties of milkweed (Asclepias), and they are therefore called "milkweed butterflies." There are two species of the genus found in our fauna, one, Anosia plexippus, Linnæus, which is distributed over the entire continent as far north as southern Canada, and the other, Anosia berenice, Cramer, which is confined to the extreme southwestern portions of the United States, being found in Texas and Arizona.

(1) Anosia plexippus, Linnæus, Plate VII, Fig. 1, ♂ (The Monarch).

Butterfly.—The upper surface of the wings of this butterfly is bright reddish, with the borders and veins broadly black, with two rows of white spots on the outer borders and two rows of pale spots of moderately large size across the apex of the fore wings. The males have the wings less broadly bordered with black than the females, and on the first median nervule of the hind wings there is a black scent-pouch.

Egg.—The egg is ovate conical, and is well represented in Fig. 4 in the introductory chapter of this book.

Caterpillar.—The caterpillar is bright yellow or greenish-yellow, banded with shining black, and furnished with black fleshy thread-like appendages before and behind. It likewise is well delineated in Fig. 16, as well as in Plate III, Fig. 5.

Chrysalis.—The chrysalis is about an inch in length, pale green, spotted with gold (see Fig. 24, and Plate IV, Figs. 1-3).

The butterfly is believed to be polygoneutic, that is to say, many broods are produced annually; and it is believed by writers that with the advent of cold weather these butterflies migrate to the South, the chrysalids and caterpillars which may be undeveloped at the time of the frosts are destroyed, and that when these insects reappear, as they do every summer, they represent a wave of migration coming northward from the warmer regions of the Gulf States. It is not believed that any of them hibernate in any stage of their existence. This insect sometimes appears in great swarms on the eastern and southern coasts of New Jersey in late autumn. The swarms pressing southward are arrested by the ocean. The writer has seen stunted trees on the New Jersey coast in the middle of October, when the foliage has already fallen, so completely covered with clinging masses of these butterflies as to present the appearance of trees in full leaf (Fig. 79).

[a]Fig. 79.]—Swarms of milkweed butterflies resting on a tree. Photographed at night by Professor C.F. Nachtrieb. (From "Insect Life," vol. v, p. 206, by special permission of the United States Department of Agriculture.)

This butterfly is a great migrant, and within quite recent years, with Yankee instinct, has crossed the Pacific, probably on merchant vessels, the chrysalids being possibly concealed in bales of hay, and has found lodgment in Australia, where it has greatly multiplied in the warmer parts of the Island Continent, and has thence spread northward and westward, until in its migrations it has reached Java and Sumatra, and long ago took possession of the Philippines. Moving eastward on the lines of travel, it has established a more or less precarious foothold for itself in southern England, as many as two or three dozen of these butterflies having been taken in a single year in the United Kingdom. It is well established at the Cape Verde Islands, and in a short time we may expect to hear of it as having taken possession of the continent of Africa, in which the family of plants upon which the caterpillars feed is well represented.

(2) Anosia berenice, Cramer, Plate VII, Fig. 2, ♂ (The Queen).

This butterfly is smaller than the Monarch, and the ground-color of the wings is a livid brown. The markings are somewhat similar to those in A. plexippus, but the black borders of the hind wings are relatively wider, and the light spots on the apex of the fore wings are whiter and differently located, as may be learned from the figures given in Plate VII.

There is a variety of this species, which has been called Anosia strigosa by H.W. Bates (Plate VII, Fig. 3, ♂), which differs only in that on the upper surface of the hind wings the veins as far as the black outer margin are narrowly edged with grayish-white, giving them a streaked appearance. This insect is found in Texas, Arizona, and southern New Mexico.

All of the Euplœinæ are "protected" insects, being by nature provided with secretions which are distasteful to birds and predaceous insects. These acrid secretions are probably due to the character of the plants upon which the caterpillars feed, for many of them eat plants which are more or less rank, and some of them even poisonous to the higher orders of animals. Enjoying on this account immunity from attack, they have all, in the process of time, been mimicked by species in other genera which have not the same immunity. This protective resemblance is well illustrated in Plate VII. The three upper figures in the plate represent, as we have seen, species of the genus Anosia; the two lower figures represent two species of the genus Basilarchia. Fig. 4 is the male of B. disippus, a very common species in the northern United States, which mimicks the Monarch. Fig. 5 represents the same sex of B. hulstii, a species which is found in Arizona, and there flies in company with the Queen, and its variety, A. strigosa, which latter it more nearly resembles.