GRAPE INSECTS 



483 



in Figure 374. A little flap is cut from the leaf and gradually 

 pulled over and down and fastened to the leaf by silken threads. 

 The inside is then 

 lined with white 

 silk, thus forming a 

 snug cocoon. At 

 the edge of a leaf, 

 it is necessary to 

 cut the flap only at 

 the ends; but when 

 the cocoon is made 

 away from the edge, 

 the flap must be cut 

 along one side also, 

 and frequently the 

 caterpillar cuts along 

 where the edge of 

 the flap is to meet 

 the edge of the leaf 

 and pulls up the leaf 

 a little to meet the 

 flap. Two to four 

 days after building 

 the cocoon the cat- 

 erpillar transforms 

 into a light greenish- 

 brown pupa (Fig. 

 368). Many of the 

 spring brood of cat- 

 erpillars pupat(^ dur- 

 ing the first week in 



July and in 12 to 14 days the purplish brown moths having 

 an expanse of a little less than half an inch begin to emerge 

 (Fig. 369). By means of the spines on its back the pupa is 



2r 



^-m. 



Fig. 



372. — ( Irape-berry moth caterpillars 

 working among young fruits. 



