446 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
and daring the last week of April and the first of May the moths are 
to.be found in great numbers." On the 6th of May the moths laid glob- 
ular eggs .04 inch in diameter, depositing them some days before the 
leaves expand. May 29 the Larvae began to hatch out just as the pop 
lars were throwing out their leaves. The larva- change but little during 
growth. At the end of July they descend and bury themselves in the 
earth, changing in a few days to pupa', without forming any cocoon. 
llu larva is from M to 2} inches long, of a drab or dingy purple ; head of a lighter 
shade and spotted with black. First segment behind the head bordered in front with 
a yellow line, indented behind : fourth to eighth inclusive, each with six very small 
yellow tubercles, two on the back, one behind, and one below each spiracle. Body 
striped from head to tail with twelve reddish lines, each bordered on both sides by an 
irregular narrow black line; six of the reddish lines are on the back and sides, one 
(interrupted) through the spiracles, and four on the abdomen. Anal segments spotted 
with black, as also first, second, and third segments. Mouth pinkish, legs pink, 
spotted with black; spiracles dark. (Bowles.) 
The moth.— This genus may be known by the large heavy body and rather small 
wings; the fore-wiugs have the costa straight, the tip subrectangular ; the male 
autenua' with long pectinations. This species is dark granite-gray, the fore-wings 
with three transverse, obscure, dusky lines, represented in rubbed specimens by 
black spots on the costa and veins. First line well curved ; second and third lines 
near together. Half-way between the third line and the outer edge of the wing is a 
fainter baud than the others, represented by a costal square spot, and a black spot on 
the inner angle. Hind wings with three transverse diffuse bands. The fore-wings 
expand 1.55 to 2 inches. 
12. The tussock caterpillar. 
Orgyia leucostigma (Abbot and Smith). 
The injury done to the silver-leaf poplar in ^New York City by this 
caterpillar has been marked; it was especially noticeable in 1883. Mr. 
F. Clarkson states that many of the trees in that city were entirely 
denuded of their foliage, particularly the silver-leaf poplar, the ailan- 
thus alone escaping attack. He suggested to the authorities the pre- 
vious spring that hand-picking of such cocoons as bore the eggs was 
the only sure way of exterminating these insects. There is good reason 
to believe, however, that what the authorities have failed to do a 
young army of parasites (Pimpla), which have put in an appearance 
during the last fortnight, are now actively attempting, and we shall 
probably be rid of this moth another year. The ova commenced to 
hatch out about the 25th of May, and the larvre began to assume the 
pupa form about the 21st of June ; ten days thereafter the imago was 
discovered depositing ova." Out of twelve cocoons four yielded the 
ichneumons. Mr. Clarkson noticed that this parasite forced its eggs 
through the cocoon on the pupa and that in every case he observed 
the pupa selected was a female, doubtless from the fact that "its plump 
condition provides the necessary food for the development of the para- 
site, which the male pupa of the moth could not furnish." (Can. Ent., 
xv, p. 168.) 
