Habitat Type and Seasonal Variation as Drivers of Mosquito Proliferation in Urban Aquatic Microhabitats

Abstract

Aedes aegypti is the primary vector species for dengue, Zika, and chikungunya viruses, and is adapted to thrive in urban environments. Their proximity to human populations and the adverse health outcomes associated with arboviral infections make mosquito control essential for reducing the risk of outbreaks and disease spread. Source reduction and larvicide applications are central components of mosquito control because they reduce adult mosquito emergence by targeting immature life stages. Therefore, our objective was to identify urban aquatic habitats used by Ae. aegypti and assess temporal variation in their contribution to immature mosquito production. To distinguish habitat use from habitat productivity, we considered larval presence as an indicator of oviposition or early-stage survival and pupal presence as evidence that a habitat supported development through most of the immature life cycle. Between July 2018 and October 2019, 2,482 inspections in Miami-Dade County, Florida, identified 2,756 aquatic habitats from which 19,466 Ae. aegypti larvae and 3,648 pupae were collected. Unique temporal trends were observed for both larval and pupal presence and abundance at county and habitat resolutions. County-level trends showed the highest larval and pupal production during Summer and the lowest pupal production during Winter. However, temporal patterns differed across habitats, supporting a context-dependent interpretation of habitat conduciveness, in which the same habitat type may support different levels of immature mosquito production depending on local environmental conditions. Our results show that habitats with frequent larval occurrence did not consistently have high pupal presence, indicating that larval presence does not necessarily reflect habitat productivity. Control strategies that prioritize habitats repeatedly associated with pupal production by season may improve year-round mosquito control, outbreak preparedness, and resource allocation.