Reducing Drosophila suzukii emergence through inter-species competition

BACKGROUNDDrosophila suzukii has dispersed widely from its native Asian range since 2008. Its arrival in the UK is resulting in economic losses in soft- and stone-fruit crops caused by larvae feeding on the flesh of ripening fruit. Although a large amount of research has been directed at controlling this pest, it is presently unknown how this invasive species interacts with native Drosophila species. RESULTSIn the work reported here, D. suzukii or Drosophila melanogaster adults were introduced to substrates pre-inoculated with the eggs of the same or the other species in a laboratory choice assay. Drosophila melanogaster adult emergence was not affected by pre-inoculation with D. suzukii. The rate of emergence of D. suzukii was significantly lower from medium pre-inoculated by D. melanogaster than from blank medium. In a subsequent experiment, significantly more D. suzukii eggs were laid in blank medium than in D. melanogaster pre-inoculated medium. CONCLUSIONThe presence of D. melanogaster in a substrate significantly reduced D. suzukii emergence and egg laying. This study raises research questions about how this reduction mechanism is driven and how it could be exploited as part of future integrated pest management practices. (c) 2017 Society of Chemical Industry