120 



FRUIT INSECTS 



for molting the larvae congregate in masses on the branches or 

 trunk (Fig. 131). 



When the caterpillars become nearly full-grown they become 



restless and wander 

 away to feed singly 

 for some days. The 

 full-grown cater- 

 pillar is about two 

 inches long and is 

 easily distinguished 

 from the apple-tree 

 tent-caterpillar by 

 having a median 

 row of wedge- 

 shaped or club- 

 shaped cream-col- 

 ored spots instead 

 of the continuous 

 median whitish 

 stripe i^resent in 

 that species (Fig. 

 130). On the ab- 

 dominal segments 

 these spots are 

 broken into two un- 

 equal parts, which 

 gives them the ap- 

 pearance of a row 

 of exclamation 

 marks. In New 

 York the caterpil- 

 lars become full- 

 grown in late May and early June, dep(niding on the season. 

 The cocoons are made of white silk, the outer layers being 



Fid. 130. — Full-grown forest tent-caterpillar.s (X Ig) 



