The interspecific competition between invasive Drosophila suzukii and endemic Drosophila melanogaster on fruit hosts

When two species have similar niches, it is likely that they will compete to either coexistence or the exclusion of the other species. The invasive Drosophila suzukii from Asia established itself in Hawaii in the 1980’s and is presumed to have been introduced into California in 2008. Since the 2008 migration, D. suzukii has spread rapidly and has been detected in Florida, Oregon, Washington, Michigan, North Carolina, Louisiana, British Columbia, Spain, Italy, Turkey, and Russia. The D. suzukii is a concern because it prefers fruit hosts prior to harvest with its serrated ovipositor. D. melanogaster is an endemic species in Washington State that lays eggs in overripe or damaged fruit. The two species may have separate ecological niches, but we have observed D. melanogaster ovipositing in fruit injuries caused by D. suzukii’s oviposition. We are presently conducting controlled studies to elucidate the interaction of these two Drosphilids in their respective fruit hosts. Our results will be discussed.