Climate-Driven Range Dynamics and Spatial Reorganization of the Oriental Hornet (Vespa orientalis) in the Western Palearctic Under Current and Future Scenarios

Understanding the climate-driven range dynamics of the oriental hornet (Vespa orientalis) is essential for ecological risk assessment and biodiversity management. This study utilized Maximum Entropy (MaxEnt) modeling to estimate current and future (2050) habitat suitability across the Western Palearctic. The model demonstrated strong predictive performance, yielding a mean cross-validation AUC of 0.95 ± 0.01 and a TSS of 0.78 ± 0.02, indicating high stability and discriminatory capacity. Jackknife analysis and response curves identified temperature annual range (bio7) and annual precipitation (bio12) as the primary environmental drivers. The species exhibits a distinct preference for moderate thermal variability and balanced moisture regimes, while extreme summer heat (bio5) and warm winter conditions (bio11) impose significant constraints. Current projections identify a high-suitability core concentrated within the Mediterranean basin. By mid-century, projections indicate a spatial reorganization marked by localized gains mainly in the eastern part of the study region alongside suitability losses across North Africa and parts of southern Europe. Multivariate Environmental Similarity Surface (MESS) analysis confirmed high model transferability across most expansion zones, despite increased uncertainty in hyper-arid and high-altitude regions. These findings underscore the dynamic nature of the V. orientalis climatic niche and provide a critical baseline for proactive biosecurity and monitoring in emerging high-risk regions. Given the global decline in Hymenoptera diversity, this study provides timely insights into species-specific responses to climate change, supporting broader efforts in biodiversity conservation and ecological risk assessment.