The Sooty Wing
Pholisora catullus
This is one of the smallest of the blackish Skippers and may be known by its small size, expanding less than an inch, and the series of five white dots near the apex of the front wing, these dots being more distinct on the under surface. The species is widely distributed, occurring over practically the whole of the United States, except in the states along the Canadian border from Wisconsin west—and in several of these it is found along their southern limits.
This butterfly is of particular interest because it is one of the comparatively few species that habitually occur in gardens and cultivated fields. The reason for this is that the eggs are laid upon white pigweed or lambs' quarter, the common garden pest of the genus Chenopodium. The eggs are laid singly, generally on the upper surface, and hatch in about five days into tiny caterpillars that make a little shelter for themselves by cutting out the edge of a leaf and folding over the blade, sewing it in place by a few silken threads. Here they remain and feed upon the green pulp of the succulent leaves either within the nest or near by outside. They remain in these cases until the time for the first moult, when they are likely to line the inside of the silken web before moulting. After this they make new cases for concealment and shelter, the cases as they grow older being generally made of two or more leaves securely bound together by silken web along their margin. When they become full grown, they spin a silken cocoon and change to yellowish green chrysalids from which the butterflies emerge a little more than a week later.
This species is supposed to be double-brooded in the north. The full-grown caterpillars of the second brood sew up their leafy cases very carefully, making them of such thick silken webbing that they are watertight. They remain in these coverings until the following spring, when each changes, still within the case, into a chrysalis from which the butterfly comes forth in April or May.
THE TRIBE OF THE SMALLER SKIPPERS
In the members of this tribe the tip beyond the club of the antenna is short and the abdomen is long enough to extend as far as or farther than the hind wings. The caterpillars have long and slender bodies with the upper part of the head, when looked at from in front, tapering rather than roundish or square. The chrysalids have the tongue-case free at the tip and projecting beyond the tips of the wing-cases.
The Tawny-edged Skipper
Thymelicus cernes
This is one of the commonest and most widely distributed of all our Skippers. It is found from Nova Scotia to British Columbia, south along the Rocky Mountains to New Mexico, Texas, and Florida. It is apparently absent west of the Rocky Mountains and along the Gulf Coast except in Florida. Its life-history was carefully worked out by Dr. James Fletcher, late entomologist to the Dominion of Canada, and in the north may be summarized thus: the butterflies come from the hibernated chrysalids in May or June. They remain upon the wing for several weeks so that worn specimens may be taken late in July or, rarely, even early in August. The females lay eggs upon grass blades. These eggs hatch about two weeks later, the larvae eating their way out of the shells so slowly that a whole day may be taken up by the operation. Each little caterpillar weaves a silken nest for itself, in which it remains concealed most of the time, reaching out to feed upon adjacent blades of grass but retiring into the nest at the least alarm. It is a sluggish little creature and grows so slowly that in the north it may require more than two months to become full fed as a larva. It is then about an inch long and has the characteristic outlines of the other Skipper larvae, with a black head and a greenish brown body. It now spins a cocoon, possibly using its larval nest as a basis, and some time later, before cold weather surely, it changes to a chrysalis that winters over.
This is the story of the life of the butterfly in the more northern parts of its range. Even in New Hampshire there seems to be at least a partial second brood, and farther south there are probably two regular broods with the possibility that a small percentage of the first set of chrysalids remains unchanged until spring.