Understanding key population drivers of the spotted wing Drosophila in cultivated and natural areas in the Andes.

The spotted-wing drosophila (SWD), Drosophila suzukii (Matsumara) (Diptera: Drosophilidae), is a serious global pest. Understanding the drivers for its success is fundamental to develop sustainable management tools. Here we aim to gain further understanding of environmental influences, seasonal patterns, and landscape complexity that could promote population growth and dynamics of SWD in the Andean region. To achieve this, traps baited with apple cider vinegar were placed in the Andean region of Patagonia, where soft-skinned fruit farming is a key activity and SWD is well established. Traps were deployed in four transects, covering cultivated areas and non-crop habitats. Trap inspections were conducted twice per month during two years, with all SWD counted and sexed. Bycatch was also recorded. We observed SWD high abundances in summer and autumn across most environments, and sustained populations in the peripheral forest and wild blackberries year-round. Farms near forests experienced higher SWD populations in summer compared to those farther away. Successful management of this global pest should consider neighboring areas to farms as part of the deployed tactics. Incorporating this knowledge to future management strategies and predictive models for SWD could help reduce this pest´s damage, while minimizing the use of pesticides.