Environmental and biotic drivers of Aedes albopictus spatiotemporal distribution in a subtropical city: A major transit hub on Argentina’s triple border

Biophysical and ecological factors are known to shape the distribution of mosquito vectors, yet their interaction across heterogeneous and rapidly transforming landscapes remains insufficiently understood. We assessed the occurrence of Aedes albopictus in relation to environmental and biotic drivers in the Iguazú Department, Misiones Province, Argentina, within the tri-border region shared with Brazil and Paraguay, a key epidemiological corridor for arboviral transmission. Mosquitoes were monitored using adult activity sensors (ovitraps) across 81 sites representing urban, periurban, and wild environments (later divided in pristine and disturbed wild) in eleven sampling sessions between April 2019 and February 2020. Environmental characterization integrated field data and remotely sensed biophysical variables at different spatial scales relevant to vector ecology, which were included in generalized linear mixed models together with the presence of Ae. aegypti as covariate to account for potential interspecific effects, and co-occurrence of both Aedes species was further evaluated using Bayesian analyses. Aedes albopictus showed a strongly stratified spatial pattern, with 30.4-30.6% positive ovitraps in periurban and disturbed wild, in comparison with 14.2% for urban and only 3.9% for pristine wild. Occurrence probability increased with intermediate levels of monthly precipitation and minimum temperature, showed nonlinear responses to vegetation cover, and decreased with impervious surfaces, explaining 67% of the variability. Co-occurrence analyses indicated positive associations in urban and periurban environments, suggesting partial niche overlap under anthropogenic conditions. Our results identify periurban and disturbed wild environments as critical ecological interfaces structuring Ae. albopictus distribution. These findings provide a robust basis for targeted surveillance and highlight the need for coordinated, cross-border vector management strategies in rapidly transforming subtropical regions.Author summary: Mosquitoes that transmit diseases are highly sensitive to their surroundings, yet we know little about how they respond to landscapes being rapidly transformed by human activities, especially in border regions where people and pathogens move frequently. In this study, we focused on Aedes albopictus, a mosquito capable of transmitting dengue and other arboviruses, in Puerto Iguazú, a subtropical city in Argentina located near the borders with Brazil and Paraguay. We monitored its presence monthly across urban, periurban, and natural environments for nearly one year. Ae. albopictus was most common in periurban areas where the city meets the countryside and in disturbed zones within protected areas such as trails and visitor facilities. In contrast, it was rare in highly urbanized centers with many paved surfaces and almost absent from pristine, undisturbed forests. Its occurrence was linked to rainfall, temperature, and vegetation, and it often co-occurred with Ae. aegypti, another important disease vector, especially in human modified settings. These findings reveal that transitional landscapes, neither fully urban nor completely wild, act as critical hotspots for this mosquito. For public health, this means that surveillance and control efforts should focus on these interface zones, and that environmental land use planning could become a key tool for preventing vector borne diseases in rapidly changing subtropical regions.