Grape Curculio, Craponius inaequalis (Say) (Coleoptera: Curculionidae)
The grape curculio is a black snout beetle, about 1/8 inch in length, which lays its eggs in grape berries. The developing larvae feed on the berries, consuming the pulp and seeds. Damage by this insect is commonly confused with that of the grape berry moth.
In the spring, adult beetles become active around the time of ‘Concord’ grape bloom. They feed for about two weeks before laying any eggs. The beetles feed on the upper surfaces of grape leaves; the damage appears as short, curved lines arranged in groups. The female deposits eggs in cavities she makes under the skin of grape berries. The white larvae are legless, which is in contrast to grape berry moth caterpillars. In about three weeks, larvae complete their development, drop to the ground and pupate. New adults emerge several weeks later and feed on grape foliage until the onset of cold weather at which time they seek a place to hibernate. There is one generation of grape curculio each season.
Current pesticide recommendations may be found HERE