Climate Filtering Governs the Distribution of Invasive Insect Assemblages Within Biodiversity Conservation Priority Areas in Guangxi, China

Biological invasions are a primary driver of biodiversity loss, with significant socio-economic repercussions. Therefore, understanding the factors influencing the assembly of invasive insect assemblages in Biodiversity Conservation Priority Areas is essential for formulating effective management strategies. This study examined the invasive alien insect fauna across three such regions in Guangxi, China, from April to November 2022, employing a systematic grid-based sampling design that encompassed 84 grids. A total of nineteen invasive alien insects from seven orders were identified, with Coleoptera (26.3%), Hymenoptera (21.1%), and Diptera (15.8%) being the most prevalent. Bactrocera cucurbitae Bezzi, 1913 (57.1% occurrence frequency) and Blattella germanica Linnaeus, 1767 (53.6%) were the most frequently observed species. Species richness exhibited significant variation among the three areas, peaking in the Western Guangxi and Southern Guizhou Limestone Area. The assemblages’ composition displayed high beta diversity, as indicated by a total Sørensen dissimilarity of 0.645, primarily driven by species turnover (0.474) rather than nestedness (0.171), which suggests the presence of distinct species assemblages across the areas. Generalized linear mixed models and Canonical Correspondence Analysis identified precipitation and temperature as the primary factors influencing species richness and assemblages’ composition, respectively. Hierarchical partitioning indicated that climatic variables, specifically precipitation (48.0%) and temperature (32.0%), collectively accounted for the majority of the variation in species richness, significantly surpassing the impact of local land cover (20.0%). In contrast, contemporary anthropogenic land use factors exhibited no significant effect. Our findings illustrate that while human activities serve as the ultimate drivers of species introductions, the subsequent assembly of invasive insect assemblages within these Biodiversity Conservation Priority Areas are predominantly shaped by climatic conditions. This highlights the essential role of climate suitability in determining the success of post-introduction establishment. Therefore, we recommend the incorporation of high-resolution climate-matching models into biosecurity screening and monitoring frameworks for Biodiversity Conservation Priority Areas, with targeted surveillance efforts directed toward regions exhibiting the highest climatic suitability.