3: Next generation biocontrol: Using experimental evolution to increase the effectiveness of native parasitoids at attacking invasive pests

We are in an era where the number of invasive species is steadily increasing while simultaneously classical biological control introductions are decreasing due to increasing regulations and costs. These trends are unlikely to change, and thus alternative methods need to be developed to control invasive pests that are safe, sustainable and publicly accepted. Native natural enemies represent a potential alternative as they often try to adopt invasive species but typically have low success rates on them. Laboratory selection, a long-recognized but rarely used method, can be used to speed up evolution and improve the performance of native parasitoids on exotic species within a few generations. We have started assessing the potential of experimental evolution to increase the virulence of native parasitoids on two highly detrimental agricultural pest species, spotted wing drosophila (Drosophila suzukii) and brown marmorated stink bug (Halyomorpha halys). We collected four native parasitoid species in Michigan: Leptopilina heterotoma (a larval parasitoid of drosophilids), Pachycrepoideus vindemmiae (a pupal parasitoid of drosophilids); and Telenomus podisi and Trissolcus euschisti that are egg parasitoids of stink bugs. Initial evaluations indicate that at least two of these four parasitoid species can develop on the target invasive species. We will present preliminary data on the potential of these species to increase their performance on invasive hosts within a few generations during laboratory selection. If this approach is successful, it could provide a safe and effective alternative or complimentary method to classical biological control.