Managing Grape Rootworm in NY Vineyards

Abstract

Historically (early 1900s) grape rootworm (GRW) was the major insect pest of grapes growing in New York and surrounding states (Johnson and Hammar 1910). Adults do some minor leaf feeding in early to mid-summer. However, larval feeding on grape roots can reduce vine vigor or even cause vine death at high densities. For various reasons, including the seasonal use of broadspectrum synthetic insecticides, the pest status of GRW declined during the second half of the 20th century. However, with the advent of more selective insecticides and the overall reduction in the number of applications during the season, reports of GRW adult feeding damage have greatly increased in recent years, especially in the Lake Erie Grape Belt. Because adults and their feeding damage are not obvious and larvae are pretty much hidden, it’s likely that the impact of GRW is greatly under estimated by New York grape growers. Insecticide, targeting adult GRW during the pre-oviposition period (time between when adults emerge from soil and the start of egg laying), is the recommended method of control.