406 FIFTH KEPORT OF THE ENTOMOLOGICAL COMMISSION. 



noticed early in August, but becomes fully fed by the first week in 

 September, my specimens transforming September 8, the chrysalis 

 euteriug the earth. I have also found it fully fed ou the white birch 

 at Brunswick as early as August 10. It also feeds on the maple. 

 The moth appears in June in Maine late in May in southern ISTew 

 England and New York. I have raised this moth in Maine from the 

 larch (pulsating September 15), also from the Misi^souri currant, an orna- 

 mental shrub ; also from the apple, elm, cherry, and the aspen iuEhode 

 Island, though the willow is probably its native food-plant, as it occurs 

 in greatest abundance on that tree. Mr. Lintner states that the larva 

 feeds on the maple ; that the caterpillar entered the ground for pupa- 

 tion August 11, the moth emerging the latter part of May. (Eut. Contr. 

 iii, 16G.) My specimens emerged in Providence May 13. The larva 

 found on the aspen is greenish and like afresh aspen twig, with whitish 

 granulations, which are black on the tubercles. « 



It is subject to the attacks of a species of Microgaster, seven larvae of 

 the latter making their exit from a caterpillar two thirds grown. The 

 following historical sketch of our knowledge of this insect is taken 

 from Mrs. Dimmock's article in Psyche, iv, p. 271. 



Amphidasys cognataria Guen^e (Hist. Nat. d. Ins., 1857, v. 9, Uran. et Phal., v, i, 

 p. 208). Cramer (Bull. Brooklyn Eutom. Soc, Aug. 1883, v, 6, p. 48) briefly describes 

 the eggs of this species, of which about five hundred were deposited June 3. Bowles 

 (Can. Entom., April, 1871, v, 3, p. 11-12) (Ann. Rept. Entom. Soc. Ontario, 1871, p. 

 38-39) describes a variety of the larva which fed on "black currant" IBibes fn'ujnim'], 

 and Goodell (op. cit., April, 1878, v, 10, p. 67) describes another variety which fed on 

 apple and pear. Lintner (Entom. Contrib., No. 3, 1874, p. 166) briefly describes the 

 larva, giving Acer as food-plant, and Packard (Guide Study Ins., 1869, p. 322) gives 

 a few notes on the larva, which he states feeds upon Rihes aureum, R. fgrossularia, 

 and Spiraea ftomenlosa. Pilate (Papilio, May, 1882, v, 2, p. 71) gives "honey-locust" 

 {Gleditschia triacantlios) as food-plant. Lintner (Entom. Contrib. [No. 1], 1869, p. 

 64) gives plum as food- plant. To the above food-plants maybe added Betula alba, 

 B. lenta, Casfanea vesca, Salix, and Sjnrma sorhifoUa. The larva varies from pea-green 

 to brownish gray or even brownish black in general color ; as far as noticed the green 

 form is from Bibes, Salix, and Sjnnea, while those from apple exhibit all the color 

 variations ; on Betula and Castanea the larvie are gray. Similar variations have been 

 noticed in the larvis of Amphidasys betularia, a European species. The larvae often 

 rest in a partially twisted position, with their rigid bodies at a considerable angle 

 from the stem to which they cling, thus imitating very closely twigs and petioles. 

 The larvae are common in New England in July and August ; they pupate from the 

 latter part of July to September, the pupa hibernating uuder leaves and rubbish. 



Young larva. — Body cylindrical ; segments much wrinkled above, but not tuber- 

 culated. Head large and square in front ; vertex very deeply notched, each tubercle 

 acute above, conical and rough, granulated ; clypeal sutures deeply impressed. 

 Prothoracic segment above broad and flat, transversely oblong, with a slight low 

 tubercle on each side in front, making the cervical shield angular in front. A 

 pair of remote but conspicuous though small round white patches on mesothoracic 

 and the seven following segments. Fifth abdominal segment with a small thick 

 tubercle low down on the side. Anal legs large, broad, and flaring. General color 

 rust-red. Length, 15"'"\ 



Larva before the last molt. —With the characters of the adult larva ; salmon red 

 Length, 35""™. 



