Unexpected latitudinal patterns in mosquito (Diptera: Culicidae) diversity along the Brazilian Atlantic Rainforest

The Atlantic Rainforest harbors nearly half of Brazil’s biodiversity, including a remarkable variety of mosquitoes (Diptera: Culicidae). While species richness in tropical biomes is typically expected to decline with increasing latitude, our study revealed the opposite: mosquito diversity increased toward higher latitudes along the Brazilian coastal Atlantic Rainforest. Through dissimilarity partitioning, we found that this unexpected pattern is primarily driven by species turnover, with marked changes in species composition along latitudinal gradients. Cluster analysis revealed two distinct biogeographic regions (South-Southeast and Southeast-Northeast) mirroring endemism centers already reported for other animal groups. These patterns likely reflect the biome’s dynamic climatic history, particularly forest contractions and expansions during the Pleistocene. This is the first study in Brazil to explore latitudinal variation in Culicidae diversity and distribution, offering new insights into the biogeographic processes shaping mosquito communities across one of the world’s most threatened biodiversity hotspots.