250 FOREST ENTOMOLOGY. 



Eothes Estate, Fife, of the caterpillars being at work in the middle 

 of summer on Balsam poplars, from some of which they had entirely 

 stripped the leaves. These trees had been planted in the previous 

 spring, and were from four to five feet high, and in another instance 

 the rapidity with which the caterpillars devoured the leaves was 

 specially mentioned. During the present year a very curious instance 

 was reported to me from Lincolnshire, in which the little trees were 

 so young and small that the quantity of woody material and bark 

 removed by the caterpillar for its cocoon had so weakened the slender 

 stem that the young poplar plant had broken off. In the specimen 

 sent me, the slender stem was completely bared of bark for some 

 little distance from the hard cocoon, and the young plantation was 

 reported to be practically destroyed." 1 



From the species above mentioned which I hatched out, I found 

 that the eggs were deposited about July 1. The eggs were brown, 

 circular, and about 2 mm. in diameter. 



Buckler gives the following description, viz. : 



" The eggs are laid either singly or two or three near together, 

 on leaves of poplar, sallow, or willow. (I fancy poplar, any kind, 

 is preferred by the larvae, when they have the choice.) The egg is 

 button-shaped, convex above, nearly flat underneath, fairly round, 

 with a small pit at the apex, varying from 1*6 mm. to almost 2 mm. 

 in wide diameter, slightly more than 1 mm. high, the shell hard, 

 glossy, but finely pitted all over, colour rich warm brown above, more 

 smoky beneath, the central pit blackish, but ringed with yellowish- 

 white. There is a pale variety of the egg of a buff tint, the central 

 pit still blackish, with light ring." 2 



The larva, when full fed, is large, stout, and smooth. It may be 

 easily recognised by the position it assumes, of arched body and 

 forked tail, which, in fact, may be termed a fighting attitude. The 

 fourth segment is surmounted by an angular hump, head black, and 

 often partially withdrawn within the body. The prevailing colours 

 of the caterpillar are brown and yellow, the former an angular por- 

 tion along the back, and the latter conspicuous when viewed from 

 the side. 



The pupa is enclosed in a very hard shell-like cocoon, which may 

 be found on the trunk of the food- tree, or, in fact, on any adjacent 



1 Manual of Injurious Insects. 



2 The Larvae of British Butterflies and Moths. (Ray Society.) 



