14 Farmers’ Bulletin 1220. 
noticed by the vineyardist until late summer and fall when the 
yellow and brown-blotched leaves fall prematurely, by which time 
the injury has been done. The insects in feeding extract large quan- 
tities of liquid food, sucking it from the leaf by means of piercing 
mouthparts, Often feeding constitutes a heavy drain on the vitality 
of the plant. The injury to and loss of leaves prevent the proper 
assimilation of food by the vines; and the fruit may be materially 
reduced in size and may lack much in flavor and sugar content (fig. 
12). Although the annual loss of grape growers from this species is 
enough to place it among the first-class pests of the vine, it is only 
comparatively recently that 
systematic efforts have been 
made to control it in some 
of the important grape- 
growing regions. There 
are numerous records of its 
injury in the Erie-Chau- 
tauqua grape region during 
the past two decades and 
growers in that region 
probably more generally 
treat, vineyards for the con- 
trol of this pest than else- 
where. In California it is 
stated to be, next to the 
phylloxera, the most impor- 
tant of all insect pests of 
the vine. 
LIFE HISTORY AND HABITS. 
The grape leafhopper is 
Fic. 12.—Defoliated condition of grapevine by late quite small, measuring not 
summer from attack of grape leafhopper. ; : 
over one-eighth of an inch 
in length, and is very agile, moving with equal facility in all direc- 
tions. It flies out from the vines often in swarms on slight dis- 
turbance. In general appearance it is light yellow, with deeper 
yellow or red markings, the exact pattern and color varying much 
among the different individuals and according to season (fig. 13). 
There are numerous varieties of the insect as based on these varia- 
tions. The winter is passed by the adults in hibernation in trash 
in and near vineyards, in the edges of neighboring woods, in grass 
along gullies, in ditches, etc. Early in the spring the insects come 
from winter quarters and attack almost any succulent vegetation at 
hand. By the time the foliage of the grape is well out, they are 
