Trichopria drosophilae parasitizes Drosophila suzukii in seven common non-crop fruits

Abstract

The invasive vinegar fly Drosophila suzukii not only infests and damages numerous fruit crops but also develops in many wild fruit species in semi-natural habitats. Biological control in these refuges could reduce D. suzukii populations and minimize their dispersal into fruit crops. We investigated parasitization of D. suzukii by the pupal parasitoid Trichopria drosophilae in seven common wild fruit species. Development and nutrient content of D. suzukii differed among the fruit species. Nevertheless, T. drosophilae significantly reduced D. suzukii numbers in all fruits. The development of T. drosophilae was affected by both the fruit species and the quality of the pupal host (size, nutrient content). In olfactometer assays, parasitoid females preferred infested fruits to an empty control and to most non-infested fruits, but spent an equal amount of time on the walking arena above the infested and non-infested fruits of Rhamnus cathartica and Viscum album. Our results show that T. drosophilae can utilize D. suzukii hosts from a variety of wild fruit species and therefore has the potential to be used as a control agent of D. suzukii in semi-natural habitats.