The Skipper caterpillars have stout bodies and are easily known by the constricted neck. Most of these have the habit of making nests from the leaves of the food plants, weaving them together with silken threads. In a similar way each also makes a slight cocoon when it is ready to change to a chrysalis.
The Skippers found in eastern North America are commonly grouped into two types—the Larger Skippers and the Smaller Skippers. The characteristics are given in the paragraph immediately following and the one on [page 278].
THE TRIBE OF THE LARGER SKIPPERS
The butterflies of this tribe have that part of the club of the antenna, which is recurved, about as long as the thicker part below it. As a rule, the abdomen is distinctly shorter than the hind wings. The caterpillars are rather short and thick, and the upper part of the head, when looked at from in front, is square or roundish rather than tapering. The chrysalids have the tongue case attached throughout its length and stopping short of the tips of the wing cases.
The Silver-spotted Skipper
Epargyreus tityrus
One can seldom draw hard and fast artificial lines in nature. There are all sorts of intermediate conditions which disturb arbitrary classifications. It might seem simple enough to say that some insects are leaf-rollers and others are tent-makers, but as a matter of fact in the case of the Silver-spotted Skipper we have an insect which starts its larval life as a leaf-roller and finishes it as a tent-maker. Its life-history is rather interesting and easily observed, if one can find the larvae at work upon the leaves of locusts and other trees. (See plates, [pages 272-273].)
The Silver-spotted Skipper is one of the largest butterflies of the interesting group to which it belongs. It lays its eggs upon the upper surface of the leaflets of locusts and other plants of the legume family. In less than a week each egg hatches into a little caterpillar with a very large head and a comparatively large body, tapering rapidly toward the hind end. This little creature cuts out from one side of the leaf a small round flap which it turns over and binds in place by silken threads to make a home for itself. This little home shows considerable variation in its construction but it usually has an arched dome held in place by strands of silk running from the eaten fragment to the surface of the leaf. It remains an occupant of this home until after the second moult. About this time it becomes too large for its house and deserts it to make a new one generally by fastening together two adjacent leaves. These are attached along the edges by silken strands in such a way as to give considerable room. It leaves one end open as a door out of which the caterpillar crawls to feed at night upon near-by leaves, returning to the house for shelter during the day. They continue to use this habitation until they are full grown as caterpillars and sometimes they change to chrysalids within it. More commonly, however, they crawl away both from the leafy case and the tree that bears it and find such shelter as they can upon the ground near by. Here they spin slight silken cocoons within which they change to chrysalids. In the more Northern states there is but one brood a year, so these chrysalids remain in position until early the following summer when they come forth as butterflies. Farther south there are two broods each summer, the second brood of butterflies appearing chiefly in August.
The Silver-spotted Skipper derives its name from the distinct silvery spots upon the under-wing surface against a background of dark brown. The butterflies appear in the Northern states early in June and remain upon the wing for several weeks, being found even in August. They fly very rapidly and are difficult to catch in an insect net except when they are visiting flowers.
This species is widely distributed, occurring from ocean to ocean over nearly the whole of the United States. It extends into Canada only in the eastern part and is not found in the Northwestern states.