THE EGG
“The egg measures about 1.12 mm. in height and .7 mm. in diameter at the widest part, barrel-shaped, with fourteen vertical ribs. A brilliant yellow at first, it assumes after about thirty-six hours a reddish brown color. A few hours later an irregular, whitish broken ring, not quite circling the egg, appears about one-third of the distance from the top. When within an hour or so of hatching the shell becomes very thin and transparent and reflects the light with a sort of frosted-glass effect. The large black head of the larva inside gives the upper one-third of the egg a black, metallic appearance, while the yellowish body may be seen curled up in the lower part. The incubation period seems to vary greatly with the temperature, from forty-seven hours to seven days.”
THE EMERGENCE OF THE CATERPILLAR
“At 2:15 p. m. the larva was clearly visible through the shell. Slight bodily movements were noted, then the very large, shining black head was thrust out at a point on one side of the egg, just below the top. The entire structure rocked and swayed slowly back and forth, inclining toward the side from which the head projected.
“At 2:19 the larva emerged very slowly, head first. The head and the final segment appeared very large. The entire length was about 1.5 mm. The body yellowish red; prolegs and caudal segment lemon yellow; the head, legs and spines black. The latter bear no visible branches, and appear as stiff, black hairs, each growing out of a slight black protuberance.
“The beautiful egg-shell remains erect, the form being unchanged. There is a ragged hole in it, but it is scarcely noticeable, and appears hardly large enough for the egress of the caterpillar.”
THE CATERPILLAR
“The newly emerged larva does not venture far from the egg-shell and does not move about much for the first five or six hours. It sometimes devours the shell, but this is not usually the case. At the age of six hours it appears darker, and the black spots from which the hairlike spines protrude have become more conspicuous. Has not eaten any of the leaf, and has increased in size very little if at all.”
“At the age of twenty-seven hours the larva attains a length of 2.3 mm. and has eaten several small holes in the center of a large leaf, gnawing through the leaf to the transparent epidermis on the opposite side, which is left intact. Usually works from the upper side, but by no means invariably.”
“These smaller larvae seem to be always attached to the leaf with silk, although the threads are very few and fine. More mature larvae feed differently; they grip the petiole with the prolegs, and eat from the edge inward and forward, swinging the head toward the midrib, with practically no lateral motion.”