Potential climate warming effects on the distribution of an invasive alien pest species

Abstract Climate warming can be a powerful driver for the establishment and further spread of alien species by lowering the abiotic resistance of native ecosystems and supporting invaders. One pivotal outcome of climate warming is more frequent heat waves in summer in temperate regions. Here, we combined heat‐stress experiments (development, fecundity) and incidence data of the spotted wing drosophila (SWD), Drosophila suzukii , from two Austrian vine‐growing areas differing in their regional climate (Illyrian vs. Pannonian climate). We used corresponding climatic data (ice and hot days) and landscape elements (forests) to evaluate whether regional‐specific climate warming effects influence the distribution of SWD. Laboratory results showed that SWD is a heat‐sensitive species, with negligible survival under moderate and extreme heat waves. Under field conditions, the incidence of SWD in Austrian vineyards and the availability of surrounding forests were higher in the Illyrian than in the Pannonian climate zone. Climate warming resulted in fewer ice days in both climate zones, but the frequency of hot days has increased more strongly in the Pannonian zone over the last few decades. We conclude that forested areas near vineyards can serve as refugia both in winter and during hot summer periods. Consequently, the lower incidence of SWD in the Pannonian zone correlates with hotter summers due to climate warming and limited access to nearby forested areas. These findings highlight the urgent need for regionally tailored pest management strategies that account for the complex interplay among climate extremes, landscape features and invasive species dynamics.