Can reproductive interference be integrated into the Sterile Insect Technique for pest control? Insights from the spotted wing fly Drosophila suzukii (NEW RESULTS)

BACKGROUND: Reproductive interference (i.e., sexual interaction between males of one species and females of another species that reduces the fitness of one or both interacting individuals) is an important species interaction that significantly affects population dynamics and persistence. However, its exploitation in pest control remains overlooked. Here, we investigated the potential integration of reproductive interference into the Sterile Insect Technique (SIT) to develop a cross-species SIT. For this purpose, we focused on the invasive pest species Drosophila suzukii and used D. melanogaster as the control species. First, we investigated the effect of irradiation on male sterility and longevity of D. melanogaster. Next, we tested the mating performance of irradiated males and their ability to reduce the fitness of D. suzukii. RESULTS: We found by microcosm experiments that: i) irradiation induced high levels of male sterility of D. melanogaster without reducing lifespan; ii) irradiated D. melanogaster males court D. suzukii females as well as D. suzukii males and they mate, reproduce and produce heterospecific females; iii) irradiated D. melanogaster males significantly reduce the offspring of D. suzukii females at different species ratios. CONCLUSIONS: Our results provide the initial basis for the development of a cross-species Sterile Insect technique against D. suzukii and fuel to test this approach against other groups of pest species.