GRAPE INSECTS 



409 



Fig. 354. — Adults of the grape leaf- 

 hopper (x 3^). 



the vine in California. 



The hoppers, l)oth 



adults and nymphs, 



suck out the sap from 



the under side of the 



leaves, which soon 



turn brown and, if 



badly infested, fall 



prematurely, leaving 



the vines unable to 



ripen their load of 



fruit or properly 



mature the new wood for next year's crop. 



The grape leaf-hopper has been studied most carefully in 



New York and in California. 

 The adult hopper (Fig. 355) 

 is scarcely an eighth of an 

 inch in length, and has the 

 back and wings marked in a 

 peculiar manner with yellow 

 and red. In the winter these 

 markings are a dark orange- 

 red, but after feeding has 

 been resumed for a short 

 time in the spring, they 

 change^ to a light lemon- 

 yellow. In all parts of the 

 country it passes the winter 

 in the adult or winged state. 

 As soon as the leaves begin 

 to die and drop from the 



vines in September and October, the active adult hoppers mi- 

 grate from the vines and seek winter quarters. Comparatively 



few of them find suitable hibernating places near the vines in 



Fig. 355. — Adult and molted nymph 

 skin of the grape leaf-hopper (x H). 



