Trapping of Drosophila suzukii

The spotted wing drosophila (Drosophila suzukii) is a newly introduced pest of soft fruits, stone fruits and grapes in Europe. Various trap types are used for monitoring and mass trapping of this pest. In Switzerland, “Gasser-Becherfalle” with a white lid and a liquid wine-vinegar based attractant is the most widely used trap type for both purposes. In order to improve efficiency of monitoring and mass trapping, two different commercially available trap models (red and white lid), as well as a standard bait supplemented with different acetone concentrations were compared in laboratory and field experiments. In addition, D. suzukii populations were monitored in different habitats in order to understand annual migration patterns and assess optimal trapping sites. The results indicate that the two trap types were equivalent. Bait attractiveness can be increased by the addition of acetone, but is highly dosage dependent. Monitoring of D. suzukii in different habitats showed that host plants are preferred habitats during summer. In November, a shift of populations towards non-host plants takes place: foliated, evergreen plants are preferred as winter habitats.