Susceptibility of grape berry moth, <i>Paralobesia viteana</i> (Clemens) (Lepidoptera: Tortricidae) to insecticides in Michigan vineyards

Grape berry moth is a major pest of vineyards across eastern North America. Increasing infestations in Michigan commercial under active management have raised concerns about insecticide resistance this species. We tested the susceptibility male moths from 5 southwestern over 2 years using range concentrations, followed by probit analysis resulting mortality data. In 2021 and 2022, topical applications phosmet zeta-cypermethrin were applied to collected each vineyard, LC50, LC90 LC99 values calculated for population. The LC50 similar among sites, whereas highly variable years, with sensitivity 2.78 times higher 2022 than at Farm 61.66-fold 3. Sensitivity was generally between level, but it LC99, two sites showing lower compared three farms an increased 2022. response carbaryl 3 both years. However, 2.34, 6.33 14.29-fold, respectively, those 5. conclusion, our results show that insecticides grape populations southwest different These highlight need continued monitoring species, development implementation alternative control strategies maintain insecticides.