12 BULLETIN 19, U. S. DEPABTMEXI OF AGEICrLTVEE. 
Ohio, in the spring of 1912 produced a brood of nymphs which 
matured to adults. These adults, in turn, produced nymphs which 
developed to adults of the second summer brood. Observations in 
the vineyards of Ohio and Michigan, however, diiring August of 1911 
and of 1912 indicate that this species produced a much smaller 
number of second-brood nymphs than did T. comes in the vineyards 
suiT'^imding Xorth East. Pa. 
It should be added that a very large percentage of the grapevines 
grown in the Michigan vineyards are of the Concord variety, and 
that on these vines T. tridncta is the predominating species, whereas 
in the vineyards of the Chautauqua and Erie grape belt, where the 
Concord is the leading variety grown. T. comes is the predominant 
and destructive species. 
Little, if any. effort has been made thus far by the vineyardists of 
Michigan to control T. tridncta, although in the season of 1911 it 
was quite destructive in many vineyards. Several Tineyardists in 
the vicinity of Lawton and Paw Paw were planning to combat it 
with a tobacco-extract spray in 1912. but although there was a 
heavy infestation of overwintering adults in the spring these failed 
to produce a large enough brood of nymphs to injure the vines seri- 
ously, thus rendering a spray treatment unnecessary. 
DESCRIPTION. 
THE ADULT OR WINGED FORM. 
The adult grape leaf hopper (TypfJ.oeyoa comes Say 1 (see fig. 1, 
p. 1 ) is an insect about one-eighth of an inch long. The original 
description of the insect by Say. made in 1S25 (see Bibliography), 
is as follows: 
Pale yeUowish with sanguineous spots. Inhabits Missouri. 
Body pale yellowish: head, a transverse sanguineous line, profoundly arcuated 
in the middle, and a smaller transverse spot before; eyes fuscous: thorax with three 
sanguineous spots, the lateral ones smaller and the intermediate one arcuated: scutel. 
a sanguineous spot at tip: hemelytra yellowish white spotted with sanguineous: spots 
arranged two at base, of which the outer one is small and the inner one elongated 
and abruptly dilated on the inner side at tip: two upon the middle, of which the 
outer one is elongated in a very oblique line: the two behind the middle, of which 
the inner one is obliquely elongated, and the outer one smaller and interrupted : and 
a transverse linear one near the tip. ramose upon the nervures: feet whitish. 
Length to the tip of the hemelytra one-ninth of an inch. 
The line and spot on the head and the spots of the thorax are sometimes obsolete, 
but are always visible, and the latter are sometimes connected by curving toward 
the anterior edge of the thorax. The spots of the hemelytra are also sometimes 
slightly interrupted, or connected into four oblique bands. 
In whiter the color markings are deep salmon-red. After the 
insects have fed upon the foliage of the grapevine for a short time 
the color becomes paler and is displaced by a light yellow. In the 
