Drosophila suzukii daily dispersal between distinctly different habitats

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an insect pest originating in South-East Asia that has invaded Europe (EU) and the Americas. This insect has caused extensive economic damage to the soft fruit industry in all countries to which it has spread. Drosophila suzukii population management relies primarily on chemical pesticides, an approach with serious drawbacks including the risk of residues on fruit and development of insecticide resistance. Drosophila suzukii dispersal from surrounding vegetation is believed to significantly increase the risk of crop damage. Despite increasing evidence that environmental configuration and composition strongly affect D. suzukii population levels and activity, the effects of landscape and abiotic factors including temperature and humidity on its movement is still poorly understood. For this reason, during the summer of 2017, we employed a mark-capture strategy using protein markers during middle July and early August. Within the experimental setup, flies were captured in food-baited traps, and later analyzed for the presence of the marker through an ELISA procedure. Our data suggest that more suitable temperature, humidity, and a diverse suite of alternative hosts found in the surrounding forest vegetation likely drove the recorded dispersion. Most of the captured D. suzukii marked within the crop were collected in surrounding forest vegetation within 24 hours of the marking event during each of the periods of collection. Results strongly indicated how humidity, temperature and alternative hosts are key drivers of D. suzukii populations in different habitats