Hunting through space: bridging the gap of biocontrol between leaf-dwelling and flower thrips in horticulture.

Biological control of plant pests is a successful and sustainable alternative to pesticide use in agriculture and horticulture. Yet, the success of biological control programmes is constantly under pressure from alien invasive species that are not suppressed by the currently employed biological control agents. In the Netherlands, the leaf-dwelling thrips Echinothrips americanus and the recently intercepted Thrips setosus are threatening the stability of biological control programs, mainly due to habitat mismatch with the anthophilous biological control agent Orius laevigatus. In the proposed research project, we first focus on evaluating several Orius predators, regarding their ability to control leaf-dwelling thrips and successfully establish in different horticultural crops. We then aim to study the food web predator-mediated interactions on a pest assemblage comprised of both invasive (leaf-dwelling) and established (flower) thrips. Finally, we aim to evaluate the multiple predator effects of spatially complementary biological control agents on overall pest suppression. Throughout the research project, we maintain a spatial approach, which we believe will contribute to both the fundamentals of spatial ecology and provide tools to enhance pest suppression in horticultural ecosystems.