Family: Chrysomelidae
Subfamily: Donaciinae
Length: 5-9 mm
Beetles in the subfamily Donaciinae live in wet environmentstheir host plants grow in ponds and marshes. It isn't always easy to identify these beetles to genus or species. In the case of the beetle pictured above, however, the host plant was a Water Lily, and the only members of this subfamily that have Water Lily as host plant are in the genus Donacia.
Other traits to look for in this genus are elytral apices that are squared off rather than rounded, and an elytral suture that is closed normally toward the rear of the beetle, and is not "gaped" open.
Insects of West Virginia