Eastern grape leafhopper: Erythroneura comes (Say)Western grape leafhopper: Erythroneura elegantula Osborn
All leafhopper species feed on the undersides of leaves, puncturing cells and sucking out the contents. In general, juice grape (labrusca) varieties are much more tolerant of leafhoppers than hybrid or vinifera varieties.
Grape leafhopper adults are orange-yellow with some dark spots and yellow lines on the wings and are about 1/8 inch long. Grape leafhopper has 1.5 to 2 generations per year, with peak abundance of adults occuring in late July and again in late August. Adults overwinter in leaf litter in or around vineyards and feed on weeds as temperatures exceed 60o F (16o C) in the spring. After mating, they move to young grape foliage in late May and early July to lay clear, crescent-shaped eggs inside the leaves. First generation eggs hatch in mid- to late June, and the flightless nymphs take a month to develop into adults. Cold, wet springs and winters are damaging to leafhoppers
Sampling for grape leafhopper
In labrusca vines, growers can sample for grape leafhopper in the third week of July to determine the need for management. Examine 100 leaves across two edge and two interior vineyard sites. At each site, inspect five leaves (leaves 3 to 7) on one shoot of five vines to determine whether the leaves are showing any white/yellow stippling on the upper leaf surface. If more than 10 leaves of the 100 show damage, apply an appropriate control for the leafhoppers. If populations are only at the vineyard edges, consider area-specific management. Insecticides applied for grape berry moth may control grape leafhopper as well.