Cutting wild grapevines as a cultural control strategy for grape berry moth (Lepidoptera: Tortricidae)

A 3-yr field study was conducted at commercial grape farms to evaluate cutting wild grapevines as a cultural control strategy for grape berry moth, Paralobesia viteana (Clemens). At each farm, wild grapevines were cut in the woods adjacent to one vineyard for control of P. viteana, whereas the comparison vineyard received no such cutting. Both vineyards received a standard broad-spectrum insecticide program for control of P. viteana and other vineyard insect pests. Monitoring with pheromone traps showed no differences between treatments in the total number of male moths trapped in both woods and vineyards. Egglaying by P. viteana was similar between the two wild grape cutting treatments in all 3 yr. During weekly samples of crop infestation by P. viteana, no differences were observed between programs in the percent of clusters infested by P. viteana larvae. Berries infested by P. viteana were collected from vineyard borders during the second and third P. viteana generations and held under controlled conditions. In all but one sample, survival of P. viteana larvae was similar between the two wild grape cutting treatments, parasitism of P. viteana larvae within vineyards was similar between the two wild grape cutting treatments on all sample dates, and similar captures of natural enemies were found on yellow sticky traps in the two treatments throughout the study. The opportunities and benefits of cutting wild grapevines as a cultural control in grape integrated pest management programs in eastern North America are discussed.