Location: Invasive Species and Pollinator HealthTitle: Releases of the parasitoid Pachycrepoideus vindemiae for augmentative biological control of spotted wing drosophila, Drosophila suzukii
|ROGERS, MARY - University Of Minnesota|
|WORTH, LEAH - University Of Minnesota|
|NIETO, DIEGO - Driscolls|
|STAHL, JUDITH - University Of California|
|DAANE, KENT - University Of California|
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2022
Publication Date: 2/17/2022
Citation: Hogg, B.N., Lee, J.C., Rogers, M., Worth, L., Nieto, D., Stahl, J.M., Daane, K.M. 2022. Releases of the parasitoid Pachycrepoideus vindemiae for augmentative biological control of spotted wing drosophila, Drosophila suzukii. Biological Control. 168. Article 104865. https://doi.org/10.1016/j.biocontrol.2022.104865.
Interpretive Summary: Spotted wing drosophila is a small fruit fly from Asia that has become a major pest of soft-skinned fruit crops (i.e, cherries, raspberries, strawberries, blueberries, etc.) in North and South America, Europe and North Africa. Control efforts are complicated by continual movement of this pest into crops from other habitats. It may be possible to use natural enemies that are already present in crops and non-crop habitats to control spotted wing drosophila across the crop landscape. In this study we tested whether releasing large numbers of a parasitic wasp could help control spotted wing drosophila in caneberry (i.e., raspberry and blackberry) fields in Minnesota, Oregon and California. Results were inconsistent. In most cases releases failed to increase parasitism levels and did not decrease numbers of spotted wing drosophila, although parasitism did increase after releases in one trial in Oregon. Larger releases of the parasitic wasp may be needed when numbers of spotted wing drosophila are high, or to overcome adverse conditions in crop fields.
Technical Abstract: Spotted wing drosophila, Drosophila suzukii, is native to East Asia but has become a major pest of soft-skinned fruit crops in its invaded range in the Americas, Europe and North Africa. Control efforts are complicated by the seasonal movement of D. suzukii into crops from non-crop or untreated-crop habitats. Biological control may help to suppress D. suzukii populations, particularly in source habitats before adult flies move into crops. However, surveys have found that few parasitoids attack D. suzukii in North America and Europe, with low levels of parasitism by the pupal parasitoids Trichopria drosophilae and Pachycrepoideus vindemiae and little or no larval parasitism. Augmentation of these resident pupal parasitoids may be a sustainable tool for D. suzukii management. Most augmentation efforts to date have focused on T. drosophilae, although P. vindemiae is the more abundant and widespread species in North America. In this study, we tested whether augmentative releases of P. vindemiae could help control D. suzukii in caneberry hoop houses in Minnesota, Oregon and California. Results were inconsistent. Most trials showed no detectable post-release effects on parasitism or D. suzukii levels, although one trial in Oregon did show elevated parasitism levels in release plots. Larger releases of P. vindemiae may be needed when D. suzukii numbers are high, or to overcome the effects of suboptimal conditions and/or dispersal.