Part 6

In recent years an ingenious friend of mine has devised a system of mounting butterflies under glass in cases made of a shell of plaster of paris, which he backs with cardboard and seals around the edges with gummed paper. Latterly he has taken to mounting them between pieces of glass which he secures in the same way. Specimens thus preserved keep well, may be handled readily without fear of injury to them, and in the glass cases both sides of their wings may be examined. A collection of butterflies mounted in this way may be stored in shallow trays and placed in scientific order. The process of mounting in this fashion is, however, somewhat laborious and expensive, and is not generally adopted by scientific men, who wish to be free to examine their specimens under the magnifying glass, occasionally touching the wings with benzine to disclose the facts of neuration, and to minutely investigate the feet and other parts of the body, which, when sealed up in the way I have described, are not easily accessible.

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Having thus briefly outlined the principal facts as to the nature of butterflies in general, and the best methods of collecting and preserving them, we now pass on to the description of the commoner species which are found on the continent of North America, north of Mexico and the Straits of Florida.

Class INSECTA (Insects) Order LEPIDOPTERA (Scale-winged Insects) Suborder RHOPALOCERA (Butterflies) Family NYMPHALIDÆ (The Brush-footed Butterflies)

The Nymphalidæ may be distinguished from all other butterflies by the fact that in both sexes the foremost, or prothoracic, pair of legs is greatly dwarfed, useless for walking, and therefore carried folded up against the breast. This is the largest of all the families of butterflies and has been subdivided into many subfamilies. Some of the genera are composed of small species, but most of them are made up of large or medium-sized forms. To this family belong many of the most gorgeously colored butterflies of the tropics, among them the brilliant blue Morphos of equatorial America.

The caterpillars, when they emerge from the egg, have heads much greater in diameter than the rest of their bodies. In the earlier stages the bodies taper from before backward, and are adorned with little wart-like protuberances, which bear hairs. In later stages these little protuberances in many genera are replaced by branching spines and fleshy projections, which impart to the caterpillars a forbidding appearance. The mature caterpillar generally has a cylindrical body, but in the subfamilies, Satyrinæ and Morphinæ, the larvæ are thicker at the middle, tapering forward and backward.

The chrysalids, which are generally marked by metallic spots, always hang suspended by the tail, except in the case of a few arctic species, which are found under a frail covering composed of strands of silk woven about the roots of tufts of grass, under which the larva takes shelter at the time of pupation.

In the region with which this booklet deals all the butterflies belonging to the Nymphalidæ fall naturally into one or the other of the following subfamilies: (1) the Euplœinæ, or Euplœids; (2) the Ithomiinæ, the Ithomiids; (3) the Heliconiinæ, the Heliconians; (4) the Nymphalinæ, the Nymphs; (5) the Satyrinæ, the Satyrs; (6) the Libytheinæ, the Snout-butterflies.

KEY TO THE SUBFAMILIES OF THE NYMPHALIDÆ OF TEMPERATE NORTH AMERICA

I. With the veins of the fore wings not greatly swollen at the base. A. Antennæ naked, not clothed with scales. (a) Fore wings less than twice as long as broad Euplœinæ. (b) Fore wings twice as long as broad and often translucent, the abdomen extending far beyond the inner angle of the hind wings Ithomiinæ. B. Antennæ clothed with scales, at least above. (a) Fore wings at least twice as long as broad Heliconiinæ. (b) Fore wings less than twice as long as broad. 1. Palpi not as long as the thorax Nymphalinæ. 2. Palpi longer than the thorax Libytheinæ. II. With some of the veins of the fore wing greatly swollen at the base Satyrinæ.

Subfamily EUPLŒINÆ (The Euplœids).

Large or medium-sized butterflies; fore wings somewhat produced at apex; hind wings rounded, never with tails; fore legs greatly atrophied in the males, somewhat less so in the females; hind wings of the males marked with one or more sexual brands which in the American species are located on or near the first median nervule; some of the oriental species are white, many are dark brown or black in color, shot with purple and violet; all of the American species are of some shade of reddish brown or fulvous, with the apex of the fore wings and the outer borders of both fore and hind wings margined widely with darker color, and the veins and nervules also darker, standing out in bold relief upon the lighter ground-color; the apex of the primary and the outer border of the secondary wings are more or less spotted with light color, often with white.

The adult caterpillars are cylindrical in form, adorned with long fleshy filaments, and with their bodies of some light shade of yellow or green banded with darker colors. The American species feeds upon the plants belonging to the family of the Asclepiadaceæ, or Milkweeds.

The chrysalis is smooth, pale in color, often ornamented with metallic spots, usually golden.

This subfamily, which is represented in the tropics of the Old World by many genera and species, is only represented in the United States by one genus, Anosia.

GENUS ANOSIA HÜBNER

Butterfly, large or medium-sized; fore wings triangular, produced; hind wings rounded, the inner margins clasping the abdomen when at rest; apex, outer margins, and veins, dark; male with sex-mark on first median nervule of hind wing. Egg ovate conical, ribbed perpendicularly and horizontally. Larva cylindrical, with long, dark, fleshy filaments before and behind; body usually pale in color, ringed with dark bands. Chrysalis pendant, stout, cylindrical, abdomen rapidly tapering, and ending in long cremaster; pale, with metallic spots.

A large genus, many species being found in the tropics of both hemispheres, but only two in the United States. The insects are “protected,” being distasteful to other animals, thus escaping attack.

(1) Anosia plexippus (Linnæus), The Monarch, Plate I, ♂; Plate C, Fig. g, egg; Figs. a-c, larva pupating; Fig. d, chrysalis.

Upper side of wings reddish brown, apex, margins, and veins black, under side paler; a double row of whitish spots on outer borders, apex crossed by two bands of light spots. Expanse of wings 3.25 to 4.25 inches. Egg pale green. Caterpillar feeds on milkweeds, and is found in Pennsylvania from June onward. Chrysalis pale green spotted with gold.

Breeds continuously. As summer comes the butterflies move north, laying eggs. The insect spreads until it reaches its northern limit in the Dominion of Canada. In fall it returns. Swarms of the retreating butterflies gather on the northern shores of Lakes Erie and Ontario and in southern New Jersey. Recently the Monarch has become domiciled in many parts of the Old World.

(2) Anosia berenice (Cramer), The Queen, Plate II, ♀.

Smaller than the Monarch; the ground-color of the wings livid brown. The markings, as shown by the Plate, are somewhat different from those of the preceding species. Expanse 2.5 to 3 inches.

This butterfly does not occur in the North, but ranges through New Mexico, Texas, Arizona, and southward.

Subfamily ITHOMIINÆ (THE ITHOMIIDS).

Butterflies of moderate size, though a few species are quite large. Fore wings at least twice as long as wide; hind wings small and rounded, without tails. Abdomen produced beyond the margin of the hind wing. Wings more or less transparent. Antennæ long and very slender, with a slender club at end, naked. Fore legs greatly atrophied, especially in the males. Larvæ and chrysalids resembling those of the Euplœinæ, the chrysalids being short, cylindrical, and marked with metallic spots. The family, with the exception of the Australian genus, Hamadryas, is confined to the New World, in the tropics of which there are swarms of genera and species. Like the Euplœinæ they are “protected.” But two genera are reported from our territory.

GENUS CERATINIA FABRICIUS

Distinguished from other allied genera by the strongly lobed costal margin of the hind wings in the male.