Dee. i, 1933 
The Three-Banded Grape Leafhopper 
421 
of the Canada Department of Agriculture, entomological branch, informs 
the writers that cymbium is the predominant form of leafhopper in 
vineyards in the St. Catherines and Niagara River district of the Province 
of Ontario. 
DESCRIPTION OF ADULT 
The species tricincta is separated from other members of the genus 
Erythroneura by its pale yellow color (during the summer) and three 
dark cross-bands, the anterior one upon the pronotum, the second one 
just forward of the middle of the elytra, and the posterior one covering 
the elytral apices. Variety cymbium (pi. 1) differs from other members 
of the species in that the first cross-band is typically restricted to the 
pronotum and is profoundly emarginate anteriorly, leaving much of the 
disk uncolored. Especially under winter coloration, specimens with 
forward-flexed pronotum may show dark pigmentation upon the anterior 
border of the scutellum. In no case, however, does this pigmentation 
overlap completely or evenly a line connecting the humeral angles. 
Seasonal color changes. —In common with other forms. of 
Erythroneura, there are marked seasonal changes in coloration, the color 
markings of the adults being more distinct and of a deeper tint during the 
colder months. The bright red longitudinal color streaks on the elytra, 
so conspicuous during the hibernating period, become pale yellow and 
indistinct after the overwintering adults appear on the grape foliage 
in spring. In summer the ground color of the elytra is creamy white 
or ivory tinted, without the pinkish tinge of fall or winter. The longi¬ 
tudinal color streaks when they first appear on newly transformed adults 
are pale yellow. During the latter part of August these markings become 
more pronounced, and gradually change from pale yellow to red as the 
season advances. The anterior cross-band changes from a velvety 
reddish brown to a shiny dark brown almost black. The eyes become 
darker and concolorous with pronotum, the vertexal vittse reddish and 
more distinct. The spot at the apex of the scutellum becomes bright 
red; the two larger spots at the base of scutellum, sometimes fused, 
yellowish or pale brown. Winter coloration is fairly complete by the 
first week in December. 
life history and seasonal history 
In its main characteristics, the three-banded hopper has about the 
same life history as the traditional grape leafhopper {Erythroneura comes 
var. comes), i. e., it winters over in the adult stage in or near the vine¬ 
yards, it attacks the grape foliage in the spring, feeding and breeding on 
the underside of the leaves, and it appears to pass through two or possibly 
three generations before frost drives it into hibernation. The hoppers 
enter hibernation with the sexes about equal in number, but after mat¬ 
ing and migrating to the grape foliage in the spring most of the males 
die, counts early in June showing about 90 per cent females. Overwin¬ 
tering adults lived in confinement the past season well into August. 
Oviposition.— The eggs are deposited just beneath the epidermis on 
the lower surface of the older grape leaves. 
Period of incubation of first brood. —The average incubation 
period of first-brood eggs in 1922 was 13.7 days, with an average mean 
daily temperature of 73.9 0 F., the maximum and minimum incubation 
periods being 17 and 11 days, respectively. As the first appearance of 
newly hatched nymphs in numbers occurred June 20, in vineyards in the 
