14 
BULLETIN 19, U. S. DEPARTMENT OF AGRICULTURE. 
species of wild grapevines did not bear out the supposition that 
deposition in rows is general in the thin-leaved varieties, for in all 
other cases where eggs were found on them they were deposited 
with an apparent disregard for regularity of position. 
Among vineyardists there is commonly a mistaken idea that the 
small, transparent globules that are seen on the new growth of the 
grapevine, especially in the early summer, are the eggs of the grape 
leafhopper. These are not eggs but are small drops of sap which 
exude from the rapidly growing leaves and tendrils. 
THE NYMPH. 
The young grape leafhopper, or nymph, when it hatches from the 
egg, is very minute, white in color, and of the same general form as 
Fig. 9. — Outline of eggs, a and 6, of grape leafhopper on underside of grape leaf with pubescence pushed 
aside. Greatly enlarged. (Original.) 
the adult, but differing from the mature parent in that it does not 
possess wings. It attains its growth by casting its skin in a series of 
five molts. These five nymphal stages are represented in Plate I. 
The time required for the nymph to reach maturity varies greatly 
with the different individuals. During the season of 1912 rearings 
were made of a large number of nymphs. 
First stage. — The newly hatched nymph has a white body and red 
eyes. It does not run very rapidly at first, but moves over the 
underside of the leaf with rather an uncertain, "wobbly" gait. The 
number of days required for this stage, from hatching to the first 
