The grape berry moth, Endopiza viteana Clemens (Lepidoptera: Tortricidae), is a primary insect pest of vineyards in eastern N. America, where it has recently caused significant economic loss. There are three or more generations per season, and late-season infestation of clusters has caused rejection of fruit and increased rot diseases. In replicated vineyard-scale trials, we compared the efficacy of the insect growth regulator methoxyfenozide for reducing E. viteana populations to that of a standard broad-spectrum insecticide program. Response of non-target insects to the selective insecticide was also compared between these programs to determine whether parasitism and predator abundance increased compared to conventional broad-spectrum insecticides. During 2003, collection of infested berries during peak infestation periods revealed significantly greater mortality of E. viteana and significantly greater parasitism in vineyards receiving the selective insecticide program. Our results from two growing seasons will be discussed in relation to how methoxyfenozide can be used to control this pest through direct and indirect mechanisms.