Releases of the parasitoid Pachycrepoideus vindemmiae for augmentative biological control of spotted wing drosophila, Drosophila suzukii

• Pachycrepoideus vindemmiae is a cosmopolitan drosophilid parasitoid. This pupal parasitoid was released in hoop houses for D. suzukii control. Trials Minnesota, Oregon and California had inconsistent results. Only one trial showed elevated parasitism levels release plots. Spotted wing drosophila, Drosophila , native to East Asia but has become major pest of soft-skinned fruit crops its invaded range the Americas, Europe North Africa. Control efforts are complicated by seasonal movement into from non-crop or untreated-crop habitats. Biological control may help suppress populations. However, surveys have found that few species attack America Europe, with low parasitoids Trichopria drosophilae little no larval parasitoids. Augmentation these resident be sustainable tool management. Most augmentation date focused on T. although P. more abundant widespread America. In this study, we tested whether augmentative releases could caneberry California. Results were inconsistent. trials detectable post-release effects levels, did show Larger needed when numbers high, overcome suboptimal conditions and/or dispersal.