An ATV-mounted mechanical applicator was designed to treat vineyards with SPLAT-GBM! for mating disruption of grape berry moth, Paralobesia viteana (Lepidoptera: Tortricidae). SPLAT-GBM was applied to vineyards in 0.8 g drops at a density of 1544 or 3089 drops per hectare for a total of 1.3 or 2.5 kg per hectare. Trials were conducted in 2008 and 2009 in vineyards receiving grower-standard insecticide sprays for control of grape berry moth and other insect pests. In the first trial, SPLAT-GBM applied twice at 1.3 or 2.5 kg/ha caused a significant reduction in grape berry moth infestation at harvest on clusters at the border of the vineyards where infestation is highest, compared with the no-pheromone control, but three applications at 2.5 kg/ha did not result in lower infestation compared with both the control and other treatments. In the second trial, application of SPLAT-GBM 2.5 kg/ha in mid-June and late-July caused a significant reduction in grape berry moth infestation at harvest on clusters at the border of the vineyards. Application in early-May and late-June resulted in infestation that was similar to the other program, but not statistically different from the control. In both trials, there were no significant differ- ences between any of the treatments of SPLAT-GBM and the control inside the vineyards where infes- tation is low. Among treatments of SPLAT-GBM, infestation was similar regardless of number, rate, or timing of the applications. This study shows that mechanical application of wax matrix drops to release pheromone is an effective method for control of grape berry moth using mating disruption