Length: 2.9-3.1 mm
The most common host plant of Erythroneura aza is Grape.
Other species in this large group have similar markings (for example, Erythroneura acuticephala). Male genitalia offer the surest route to a more certain ID, for those who need a more certain ID.
Nationally, many specimens of this species have been collected in the Ohio River Valley, though there are no published records from West Virginia. The hopper shown here had its photo made in Upshur County in late July when it showed up at a mercury vapor lamp.
Insects of West Virginia