Distribution and seasonality of Aedeomyia (Aedeomyia) squamipennis Theobald, 1901 in the Coastal Plain of Rio Grande do Sul, Brazil: Ecological and epidemiological implications

Aedeomyia squamipennis is the only Neotropical representative of a genus recognized ornithophilic behavior and potential involvement in the transmission of avian malaria and arboviruses. Despite its broad distribution in South America, ecological information on its habitat preferences and seasonal patterns remains scarce. This study investigated the spatial distribution and climatic factors associated with Ad. squamipennis in three habitat types within the Coastal Plain of southern, Brazil, an ecologically relevant region for migratory and overwintering birds. Mosquitoes were sampled monthly from August 2014 to May 2015 in urban, rural, and forested environments across multiple municipalities. Abundance patterns were compared using nonparametric tests, and correlations with mean temperature, precipitation, and relative humidity were assessed. A total of 1,156 specimens were collected, with higher abundances in rural (79.1%) and forested areas (20.7%), whereas urban environments contributed only 0.2% of captures. Ad. squamipennis abundance was significantly higher in rural habitats compared with other areas (p < 0.05). Population peaks showed a strong positive correlation with temperature (r = 0.84; p = 0.0026) and a negative correlation with relative humidity (r = − 0.86; p = 0.0020), indicating that warmer and less humid conditions favored adult activity. The species was primarily associated with rural flooded areas and adjacent forested habitats. Temperature and humidity were the main drivers of its population dynamics, highlighting seasonal fluctuations in abundance and implications for parasite transmission. These findings support integrated monitoring of ornithophilic mosquitoes and advance understanding of ecological interfaces relevant to avian parasite circulation within a One Health framework.