118 MANUAL OF VEGETABLE-GARDEN INSECTS 



less regular rows, sometimes crowded closely together but more 

 often rather widely separated. The egg (Fig. 73) is about 

 yV iii^^"!! ill length and flattened on three sides; the side next 

 to the leaf is somewhat concave. When first laid it is whitish, 

 but soon turns to a yellowish brown and gradually becomes 

 darker as the time for hatching approaches. 



The eggs hatch in six to fifteen days. The young bug leaves 

 the egg through an opening at one end made by pushing out a 

 small circular disk-like piece of the shell. The newly hatched 

 nymph is gayly colored ; the body is green, the legs, antennae 

 and beak rose color and the head and the front part of the 

 thorax another shade of rose. After a 

 few hours the rose color changes to 

 black. In the course of its development, 

 the insect passes through five nymphal 

 stages, molting its skin five times and 

 acquiring wings at the fifth molt. After 

 ■ the first molt, the color of the nymphs 



is a pruinose gray, almost white. Four or five weeks are 

 passed in the nymphal stage. The young nymphs hatching 

 from a cluster of eggs remain together for some time 

 feeding on the underside of the leaf. After the first molt, 

 they move about more freely. When not feeding, the older 

 nymphs and the adults often congregate around the base of 

 the plant or hide under lumps of earth. The feeding of the 

 nymphs causes the injured leaves to wilt, curl up, turn brown 

 and die. Sometimes the bugs kill the plant outright but more 

 often they merely injure it so that growth is checked and the 

 vine is unable to mature a full crop of fruit. The nymphs 

 begin to reach maturity in August but it often happens that 

 frost kills the vines while many of the bugs are still immature. 

 In such cases they often congregate on the unripe fruits, from 

 which they are able to extract enough food to complete their 

 growth. There is only one generation annually. 



