1910 



EXTOMOLOGICAL SOCIETY. 



75 



The larvae again moulted on the 23rd of July. Their vacated skins were left 

 in rows adhering to the mid-ribs of the leaves which they had skeletonized. Their 

 body colour was now black. As in the previous moult the head, etc., were green 

 at first, but soon changed to black. The whole body was firm and glossy. There 

 was a double line of yellow along the back ; and the sub-dorsal, side, and spiracular 

 lines w^ere yellow. There was a row of spike-like protuberances around the seg- 

 ments on the upper side — on the anal segment there was a cluster of such protuber- 

 ances. In this stage the larvae attained a length of one and one-sixth inches. 



They moulted again on August the 4th. Their length after the moult was 

 one inch and five-twelfths of an inch. 



The larvffi reached their full growth by the second week in August. They 

 were then two and a quarter inches long, cylindrical, glossy black with very con- 

 spicuous yellow lines. The spiracles were black. There was an oblong yellow spot 

 over each of the prop-legs and a similar spot on either side of following segments. 

 The thorny protuberances on the segments were well developed, and at the end of 

 the body there was a cluster of such protuberances. 



The larvae began to enter the soil on the 10th of August; and before the end 

 of it, all in my keeping had -buried themselves; but, so late as the 13th of Sep- 

 tember, I found in the woods a solitary straggler of the species. 



The pupa is finely sculptured. Its abdominal segments are boldly outlined ; 

 and from the last of them projects a stout spine forked at the end. This probably 

 serves as a lever, to enable the chrysalis to work its way to the surface of the earth, 

 when the imago within it is nearing perfection. 



In rearing the larvae of A. virginiensis two particulars drew my attention 

 specially. One was tliat, in the later stages of their growth, some of the caterpil- 

 lars were much smaller than the others. In the fmal stage the smaller ones were 

 only two-thirds the size of the larger, I should say that these were the undeveloped 

 males, for the male moths of the species are much smaller than the females. 



Fig. 11. Oak leaves skeletonized by Anisota virginiensis : (a) vacated skins of 

 larvae ; (h) Larvae bunched together for mutual protection. 



The other particular was, that the larvae in their later stages, had the habit 

 of grouping themselves into clusters at the ends of the mid-ribs of the leaves which 

 they had skeletonized. In these positions they somewhat resembled the small webs, 

 that, in August, are so frequently to bo seen on forest trees. (Fig. 11). 



