Seasonal and environmental patterns of naturally occurring parasitoids with potential to attack the invasive pest Drosophila suzukii in the Andes

Landscape complexity shapes insect spatiotemporal population dynamics and trophic interactions. In this context, understanding seasonal and environmental patterns of potential resident natural enemies of novel polyphagous herbivores, such as the globally invasive fruit fly pest Drosophila suzukii, is fundamental for developing effective landscape-scale pest management strategies. Here, we investigated for the first time in the Andean Patagonian region of Argentina the spatiotemporal dynamics and parasitism of three resident parasitoids-Leptopilina heterotoma, Pachycrepoideus vindemiae, and Spalangia endius-with the potential to attack D. suzukii across heterogeneous landscape including fruit crops and surrounding natural habitats. All three parasitoid species were recorded across all environments, although their seasonal dynamics differed. L. heterotoma peaked in spring, P. vindemiae in summer, while S. endius showed a non-significant tendency toward higher activity in autumn. We further provide the first field-based evidence in the region that S. endius successfully attacks and completes development in D. suzukii, and that D. suzukii exploits wild fruit species as alternative hosts. These findings highlight the need for further research on the pupal parasitoid S. endius to assess its potential as a suitable candidate for the development of biological control strategies.