Adaptation of the Polyphagous Pest Drosophila suzukii: Role of the Interactions between Fly Genotype, Microbiota and Host Fruit – ADAGIO

Adaptive phenotypic plasticity and local adaptation are two evolutionary processes that can help polyphagous insects to track changes in their host plants. Both processes can result in a higher oviposition preference or a higher offspring performance on host plants from which insect populations originated, than on alternative host plants. Evolutionary ecologists have traditionally viewed the genetic and plastic responses of phytophagous insects to their host plants as directly induced by the host plant itself (e.g. the acclimation to a novel host plant can modify insect oviposition preference or performance). In contrast, the role of plant-specific microbiota in driving genetic and plastic responses of insects to their host plant remains poorly understood. ADAGIO aims to test whether fruit-specific microbiota play a role in the genetic and plastic responses of the invasive pest Drosophila suzukii to its host fruits. To achieve this aim, we will sample natural populations of D. suzukii and their microbial communities across different fruits and combine experimental with genomic approaches. More specifically, we will: (i) compare the microbial communities of fruits, larvae and adult flies, (ii) test for the adaptive phenotypic plasticity of fly populations through fruit-specific microbiota, (iii) test for an interaction between this adaptive phenotypic plasticity and the process of local adaptation, and (iv) identify fly genetic variants associated with the host fruit or the microbiota of fly populations. This project represents a unique opportunity to increase our understanding of how the microbiota mediate the interaction between insect pests and their host plants. In addition to improving our knowledge of this interaction in D. suzukii, ADAGIO will have important applied impacts and will help in the development of innovative strategies for the management of this invasive pest.