Unravelling the activity rhythms of urban vector mosquitoes with smart-trap technology

Understanding mosquito activity in dense urban areas is essential to assess human exposure to nuisance and health risks. We analyzed real-time mosquito data from four smart traps operating between 2021 and 2024 in Barcelona (NE Spain), focusing on the fine-scale temporal dynamics of two major urban vector species, Aedes albopictus and Culex pipiens. Both species exhibited consistent bimodal diel activity patterns aligned with sunrise and sunset, with species-specific differences in peak intensity and timing as well as seasonal fluctuations. Using a random forest framework, we identified light-related cues as primary activators of mosquito host-seeking activity; and light cues, temperature and rainfall also acting as modulators of activity, roles varying by species and temporal scale. This activator-modulator perspective illustrates how intrinsic circadian rhythms interact with extrinsic environmental drivers to determine mosquito activity across temporal scales. Our findings highlight the ecological value of high-resolution monitoring and the potential of next-generation surveillance tools to support early warning systems and evidence-based vector control in the context of smart cities.