Efficacy of Selected Insecticides for Management of the Multicolored Asian Lady Beetle on Wine Grapes Near Harvest

Abstract

As one component of an Integrated Pest Management program for Midwestern wine grapes, we examined the efficacy of several insecticides on adults of the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). For field trials, percentages of clusters with at least one H. axyridis were recorded for each plot before treatment and on the day of harvest. We also examined the efficacy of insecticides under laboratory conditions via two routes of exposure, topical application and insecticide residues. In the 2004 field trials, the percentage of clusters infested with H. axyridis adults at harvest was statistically lower in plots treated with bifenthrin applied 7 days before harvest (DBH), carbaryl 10 DBH, and in plots covered with floating row cover compared to the untreated plots. In 2005, the percentage of clusters infested with H. axyridis adults at harvest in plots treated with zeta-cypermethrin 7 DBH, bifenthrin 22 and 7 DBH, and imidacloprid 1 DBH was statistically lower than beetle infestation in the untreated plots. In the laboratory, bifenthrin, carbaryl, and thiamethoxam were lethal to H. axyridis adults 7 days after treatment. Based on the efficacy results, labeled insecticides, pre-harvest intervals, and the late-season influx of H. axyridis infestations, chemical control is currently limited to carbaryl, malathion, and/or imidacloprid.Accepted for publication 13 June 2006. Published 3 October 2006.