2 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
toward the latter end of the summer its presence in more or less 
destructive numbers was evident throughout the entire grape belt. 
By far the greater injury occurred, however, in those vineyards por- 
tions of which have been continuously infested. With the general 
increase of this pest throughout the Lake Erie Valley there has 
developed a feeling of anxiety on the part of many vineyardists 
and a general inquiry is being made as to the best means of holding 
it in check. 
Heretofore the chief factors in the lack of success of the vineyard- 
ist in his efforts to combat this pest have been that he has either 
failed to recognize the most vulnerable stage in its life history or 
else he has minimized its capacity for injury until this period has 
passed, only to be filled with regrets later in the season when his 
vines are swarming with the winged adults and the foliage is so 
badly injured by them that it presents a brown and scorched appear- 
ance which renders it functionless at a period when healthy leaves 
are necessary to the plant for the purpose of elaborating the sugar 
of the fruit and for the proper maturing of the new growth so that. 
it will withstand the severity of the winter and make a vigorous 
growth in the following spring. If, however, the vineyardist will 
acquaint himself with the habits and development of this pest there 
is no doubt that he can combat it successfully when it is in the im- 
mature stages, before its wings are fully developed, by the thorough 
application of a contact spray. 
CHARACTERISTICS AND HABITS OF THE GRAPE LEAFHOPPER. 
3efore proceeding to discuss remedial measures, the primary object 
of this. paper, it may be well to consider briefly the characteristics, 
habits, and life history of the grape leafhopper, inasmuch as they 
vary greatly from those of another very destructive pest of the 
grapevine, namely, the grape rootworm. 
The grape leafhopper is a minute insect, less than one-eighth of an 
inch long. The body and wingsare of a lght yellowish color, and the 
wings entirely envelop the upper part of the abdomen in a rooflike 
covering when the insect is at rest. This position of the wings has 
an important bearing on the killing effect of a contact spray. As the 
hibernation period approaches, the more pronounced yellow marking 
of the wings and body changes to an orange-red, which, however, 
exists only during the winter months and disappears after the insect 
has fed for a short time on the folage of the vine during the follow- 
ing spring. These winged forms are the mature or adult insects and 
are the forms most familiar to the casual observer. The adults are 
frequently found in large numbers leaping and flying actively among 
the foliage of the vines during the early part of the grape-picking 
season, in September and early October. Sometimes during bright, 
