Early Stages.—The eggs are spindle-shaped, marked with vertical ridges and cross-lines. The caterpillars are cylindrical, relatively long, generally green in color, longitudinally striped with darker or paler lines. The chrysalids are generally more or less pointed at the head, with the wing-cases in many of the genera greatly developed on the ventral side, forming a deep, keel-shaped projection upon this surface.
This subfamily is very large, and is enormously developed in the tropics of both hemispheres. Some of the genera are very widely distributed in temperate regions, especially the genera Pieris and Colias.
Genus DISMORPHIA, Hübner
"I saw him run after a gilded butterfly; and when he caught it, he let it go again; and after it again; and over and over he comes, and up again; catched it again." Shakespeare, Coriolanus.
Butterfly.—The butterflies are medium sized, varying much in the form of wing, in some species greatly resembling other Pierinæ in outline, but more frequently resembling the Ithomiid and Heliconiid butterflies, which they mimic. Some of them represent transitional forms between the type commonly represented in the genus Pieris and the forms found in the two above-mentioned protected groups. The eyes are not prominent. The palpi are quite small. The basal joint is long, the middle joint oval, and the third joint small, oval, or slightly club-shaped. The antennæ are long, thin, terminating in a gradually enlarged spindle-shaped club; the fore wings being sometimes oval, more frequently elongated, twice, or even three times, as long as broad, especially in the male sex; the apex pointed, falcate, or rounded. The cell is long and narrow. The first subcostal vein varies as to location, rising either before or after the end of the cell, and, in numerous cases, coalescing with the costal vein, as is shown in the cut.
Early Stages.—Of the early stages of these interesting insects we have no satisfactory knowledge.
[a]Fig. 138.]—Neuration of the genus Dismorphia.
The species of the genus belong exclusively to the tropical regions of the New World. There are about a hundred species which have already been named and described, and undoubtedly there are many more which remain to be discovered. These insects can always be distinguished from the protected genera which they mimic by the possession of six well-developed ambulatory feet in both sexes, the protected genera being possessed of only four feet adapted to walking.