THE CANADIAN ENTOMOLOGIST. 



43 



days the female deposits her eggs, glueing them singly to the under side 

 of the leaves, usually one only on a leaf, but occasionally two or even 

 three may be found on the same leaf. 



The egg is about one-tenth of an inch in diameter, slightly convex 

 above and below, the convex portions whitish, and the nearly cylindrical 

 sides brown. Each female will lay from two to three hundred eggs, which 

 hatch in ten or twelve days. 



This insect is subject to the attack of many foes, particularly while in 

 the larval state. A large number fall a prey to insectivorous birds, and 

 they also have insect enemies. A large ichneumon fly, Ophmi macrurum, 

 see fig. 7, is a special and dangerous foe. This active creature may often 

 be seen in summer on the wing, searching among the leaves of shrubs 

 and trees for her prey. When found she watches her opportunity, and 

 places quickly upon the skin of her 

 victim a small, oval, white egg, 

 securely fastened by a small quan- 

 tity^of a glutinous substance at- 

 tached to it. This is repeated until 

 eight or ten eggs are placed, which 

 in a few days hatch, when the tiny 

 worjiis pierce through the skin of 

 the caterpillar and begin to feed on 

 the fatty portions within. The 

 Polyphemus caterpillar continues to 

 feed and grow, and usually lives 

 long enough to make its cocoon, 

 when, consumed by the parasites, it 

 dies ; in the meantime the ichneumons having completed their growth, 

 change to chrysalids within the cocoon, and in the following summer in 

 place of the handsome moth there issues a crop of ichneumon flies. It 

 is also subject to the attacks of another parasite, a tachina fly. Should 

 the insect ever appear in sufficient numbers to prove troublesome, it can 

 be readily subdued by hand-picking. This larva feeds on a variety of 

 trees and shrubs, such as plum, oak, hickory, elm, basswood, walnut, 

 maple, butternut, hazel, rose, &c. 



As this moth has been found to be easily propagated, extensive experi- 



