Insect and Fungous Enemies of the Grape. 15 
out in numbers and infest the vineyards. The adult hoppers of the 
hibernating generation feed and breed on the lower or early appear- 
ing grape leaves, gradually disappearing as the season progresses, 
but not before some of their progeny have reached the adult condition. 
Eggs are placed just beneath the epidermis in the lower leaf sur- 
face, usually singly, but also in groups. When just hatched the young 
hopper or nymph is very small, whitish in color, with red eyes, 
later becoming striped with yellow. The nymphs (fig. 13, c) feed 
in the same manner as the parents, sucking juice from the leaves, at 
first from the lower surface of the older leaves where they were born 
Fic, 13.—Grape leafhopper: a, Mottled appearance of injured grape foliage; b, the adult 
hopper; ¢c, nearly full-grown nymph. 
but later spreading more or less generally over the plant. They are 
very agile, running in all directions, but do not leap or hop. In 
the course of their growth they molt several times, and the cast skins 
are usually in evidence in numbers on the lower surface of infested 
leaves (fig. 14). 
In the northern States there is each year one full brood of nymphs 
and a partial second, the extent of the second varying according to 
season. Farther south the second generation is doubtless complete, 
with perhaps a third in some sections. By late summer and fall the 
insect is often exceedingly abundant, and all stages are to be found 
