Effective and economical control of grape berry moth, Paralobesia viteana (Lepidoptera: Tortricidae), using temporally and spatially targeted applications of reduced risk insecticides

Grape berry moth (GBM) is the most damaging insect pest of Michigan’s 12,000 acres of juice grape vineyards. In high pressure vineyards, 75 to 100 percent of grape clusters on vineyard borders can be infested with GBM. However this high level of infestation is generally only found on vineyard borders, thus the majority of area in a vineyard has low incidence of GBM damage. This project aimed to determine the effectiveness of grape berry moth (GBM) controls applied at timings based on a predictive model for GBM phenology, and sought to compare the efficacy and cost of border sprays of reduced risk insecticides (IPM Program) compared to vineyards that received a standard program where conventional insecticides were applied to the entire vineyard.  Over three seasons, at border locations, grape berry moth infestation was significantly reduced in the IPM vineyards compared to that in vineyards that received the standard insecticide program. Infestation in vineyard interiors was lower than at the border, but no significant differences were detected between programs. Additionally, per acre insecticide cost was  lower for IPM program vineyards. This work demonstrates how reduced risk insecticides can be combined with phenology models and spatially-specific applications to effectively and economically control an important pest of vineyards in eastern North America.