148 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



chrysalis, without spinning a regular, even, thin cocoon. It remains in 

 the chrysalis state about six days. Those pupating at Brunswick, Me., 

 June 28 and 29, issued as moths July 4 and 5. When the moth is ready 

 to break forth from the pupa, the latter wriggles part way out of its 

 hiding place, and the moth issues, leaving the rent pupa skin projecting 

 half way out of the end of the shoot. The moths then appear from the 

 first to the middle of July. July 16, after our return from an absence 

 of two weeks, we found that the moths of both sexes had issued, and that 

 the females had laid their eggs in curious little patches on the sides of 

 the breeding-box. They must have issued about the 5th to 7th of July, 

 and immediately laid their eggs, as in one patch the shells were empty, 

 with a small orifice in the shell, out of which the larvae had crept. 

 Another patch was found with a dark spot in each egg showing the 

 head of the embryo caterpillar ; these hatched July 18, 19. It thus appears 

 that the embryo develops, and the caterpillar hatches, in about ten days 

 after the eggs are laid. 



The eggs are very curious and very unlike those of most moths. They 

 are pale green, scale-like, broad, flat beneath, moderately convex above, 

 oval cylindrical, a little longer than broad, and in all those which I ex- 

 amined, both those containing the embryos, and those which were empty, 

 the surface, contrary to Professor Fernald's statement, was under a lens 

 seen to be finely but irregularly granulated. The shell is thin, and at first 

 unusually soft. Length, 0.9-1.4 mm ; breadth, 0.8- l mm . The patches 

 were about 3 mm in diameter, and composed of as many as 30 eggs. 

 The eggs overlapped each other irregularly, leaving about a third or 

 fourth of the surface of each egg exposed. 



From the form and size of the egg-mass it is evidently attached by the 

 moth to a terminal twig. The caterpillars on hatching do not, as Fernald 

 observes, eat the shell. They hatch about or soon after the middle of 

 July, and it is most probable that the caterpillars become partly, per- 

 haps almost wholly, grown before the end of autumn, and pass the winter 

 among the terminal shoots of the tree, to finish their transformations the 

 following June and July. It is certain that there is but a single brood of 

 caterpillars. Professor Fernald, in his article in the American Naturalist, 

 describes the process of egg-laying. He has bred from the worms an 

 ichneumon (Pimpla conguisitor), several dipterous parasites and a hair- 

 snake. We have found the insect to be remarkably free from parasites, 

 having bred about 25 of the moths without rearing any parasites. 



DESCRIPTIVE. 



Larva, first stage. When first hatched the young caterpillar is uniformly pale pea- 

 green, with a yellowish tint. Head dark brown, but the cervical shield pale amber, 

 with two dark dots on the hinder edge ; hairs nearly half as long as the body is thick; 

 length 2.5 mm . At this time the young worms are very active, letting themselves 

 down by a thread as readily as when fully grown. 



Larva before last molt Body not quite so thick as full-fed worm; more uniformly 

 rust-red brown; the piliferous warts duller in color, sometimes not much paler than 

 the rest of the body towards the head, though higher and more distinct towards the 

 end of the body. Head black and prothoracic shield black, the latter pale on front 

 margin; no well-marked, broad, lateral, yellowish-brown band such as characterizes 

 the adult. Length 12-13 ram . 



Larva (full-fed). Body unusually thick and stout, tapering gradually from the 

 middle to the end, and slightly flattened from above, as usual ; head not quite so wide 

 as the body, of the usual form, dark, almost black-brown, but lighter than before the 

 last molt; mouth-parts dark, with paler membranous rings at the articulations; 

 antennae with the terminal joint black. 



Prothoracic shield pale brown, paler than the body, with a pair of dark blotches on 

 the hinder edge in the middle, and other scattered, smaller, dark, irregular blotches, 

 of which two are situated in the middle of the front edge, the latter pale whitish. 



Body rich mnber-brown, diffused with olive-green, especially on the sutures; with 



