406 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
noticed early in August, but becomes fatly fed by the first week in 
September, my specimens transforming September 8, the chrysalis 
entering the earth. I have also found it fully fed <>n 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 New 
England and New York. I have raised this moth in Maine from the 
larch (pupating September 15), also from the Missouri currant, an orna- 
mental shrub; also from the apple, elm, cherry, and the aspen in Rhode 
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. (Ent. Coutr. 
iii, 16G.) My specimens emerged in Providence May 13. The larva 
found on the aspen is greenish and like a fresh 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 Gueue'e (Hist. Nat. d. Ius., 1857, v. 9, Uran. et PhaL, v, i, 
p. 208). Cramer (Bull. Brooklyn Entoin. Soc, Aug. 1883, v, 6, p. 48) briefly describes 
the eggs of tbis species, of wbich about five buudred were deposited June 3. Bowles 
(Cau. Eutoin., April, 1871, v, 3, p. 11-12) (Ann. Rept. Entom. Soc. Ontario, 1-71, p. 
38-39) describes a variety of the larva which fed on "black currant" [Iiibes f nigrum'], 
aud Goodell (op. cit., April, 1878, v, 10, p. 67) describes another variety which fed on 
apple and pear. Lintner (Entom. Contrtb., 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 Iiibes aureum, Ii. fgrossularia, 
and Sj)iraea ?tomentosa. Pilate (Papilio, May, 1882, v, 2, p. 71) gives " honey-locust '' 
(Gleditsehia triacanlhos) as food-plant. Lintner (Entom. Contrib. [No. 1], 1869, p. 
64) gives plum as food- plant. To the above food-plants may be added Betula alba, 
B. hnta, Castanea vesca, Salix, and Spiraa sorbifolia. 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 Eibes, Salix, and Spira'a, while those from apple exhibit all the color 
variations ; on Betula and Castanea the larva? are gray. Similar variations have been 
noticed in the larva? of Amphidasys betularia, a European species. The larva? 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 aud petioles. 
The larva3 are common in New Euglaud in July and August ; they pupate from the 
latter part of July to September, the pupa hibernating under leaves and rubbish. 
Young larva. — Body cylindrical; segments much wrinkled above, but not tuber- 
culated. Head large aud square in front ; vertex very deeply notched, each tubercle 
acute above, conical and rough, granulated; clypeal sutures deeply impressed. 
Prothoracic segment above broad ami 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. Aual legs large, broad, and flaring. General color 
rust-red. Length, 15 mm . 
Larva before the last molt.— With the characters of the adult larva ; salmon red 
Leugth, 35" n ". 
