New species in an ecosystem can exert an influence on native species either directly through competition, or indirectly through changes in food sources. They can also alter the balance between native species and their natural enemies.
Discovered in Switzerland for the first time in 2011, the spotted-wing Drosophila Drosophila suzukii has since then established a presence over virtually the entire country. Unlike native Drosophila species, D. suzukii can oviposit into and develop within undamaged fruits.
We investigate whether native Drosophila species can benefit from D. suzukii damaging the fruits, or whether they represent competition for the native species. We also investigate whether the interaction between native Drosophila and the exotic D. suzukii are influenced by parasitoids, which deplete populations through parasitisation.