Diversity and seasonal dynamics of mosquitoes in urban water drainage systems: Insights into sanitary relevant species in Salta, Argentina

Abstract

Urban environments offer favourable conditions for mosquito proliferation, supporting the transmission of diseases such as dengue and West Nile virus. Although fewer than 10% of the more than 3700 known mosquito species act as vectors, many thrive in cities due to climate, habitat availability and proximity to humans. Salta, northern Argentina, an understudied yet highly diverse region regarding mosquito fauna, is undergoing rapid urban growth. This study addresses a key gap by examining mosquito species developing in Salta's urban drainage channels. Understanding species composition in these settings is essential for guiding sustainable, targeted vector control, especially as urbanization and insecticide resistance alter transmission dynamics. Salta, the provincial capital, has experienced notable demographic expansion in recent decades. The city is intersected by drainage channels designed to manage rainwater and mitigate flooding. Fourteen sampling sites were selected across varied urban sectors, covering most of the channels and representing different channel conditions. Larvae and/or pupae were consistently found at over 80% of sites, and at least 10 mosquito species were identified across the genera Culex, Anopheles, Aedes and Lutzia , demonstrating the ecological significance of these habitats. Medically important species, including Culex quinquefasciatus and Aedes aegypti , were detected. The former was dominant across all seasons, with its abundance negatively correlated with pH and positively with water depth. These findings provide the first documentation of drainage channels as mosquito larval habitats in the region and show that urban drainage infrastructure can support diverse mosquito assemblages, including species with contrasting ecological requirements. By highlighting the role of habitat heterogeneity and environmental conditions in shaping mosquito communities, this study contributes to a broader understanding of mosquito ecology and vector persistence in rapidly urbanizing environments.