Global environmental niche dynamics of two invasive Aedes mosquitoes, Aedes japonicus and Aedes koreicus (Diptera: Culicidae), using comprehensive native and non-native occurrence data

Abstract Background Identifying areas at risk of invasion is essential for effective surveillance and management of invasive species. Two invasive mosquito species originating from East Asia, Aedes japonicus and Aedes koreicus , are of importance in Europe and America. Whether these invasive mosquitoes retain their environmental niches after introduction remains uncertain. Moreover, environmental niche dynamics of these species, particularly for Ae. koreicus , remain poorly understood. This study aimed to quantify niche dynamics of both species by comparing environmental niches between native and non-native populations. Methods We compiled occurrence records of Ae. japonicus and Ae. koreicus from published sources, databases, and field collections, and applied data cleaning and spatial filtering to reduce sampling bias. The final dataset included 2,623 for Ae. japonicus and 501 for Ae. koreicus . Environmental space was defined using selected bioclimatic variables and elevation. Within this space, we quantified environmental niche overlap and dynamics using Schoener’s D and metrics of stability, expansion, and unfilling across species, regions, and invasion status. Results The two species occupied distinct environmental niches in their native ranges but showed niche convergence in their non-native ranges. For both species, environmental niche comparisons between native and non-native populations revealed subtle but significant niche differentiation. Niche dynamic analyses indicate high environmental niche stability (0.821 in Ae. japonicus and 0.776 in Ae. koreicus ) with low environmental niche overlap values. Native subpopulation comparisons suggested potential invasion origins, with the Japanese population likely representing the source of Ae. japonicus and the Chinese population representing a potential additional source for Ae. koreicus in Europe alongside the previously suggested Korean population. Conclusions Our results show that these two invasive mosquito species exhibit convergent environmental niche shifts after introduction. Environmental niche comparisons between native and non-native populations show niche differentiation for both species and also provide insights into invasion origins. Incorporating comprehensive native occurrence data is critical for improving predictions of invasion risk and supporting surveillance and management of invasive mosquito species.