Post-biting behavioral reprogramming underlies reproductive efficiency in Aedes aegypti mosquitoes

The global spread and increasing populations of disease vector mosquitoes expose hundreds of millions of people to mosquito-borne illnesses each year. Female Aedes aegypti mosquitoes, global vectors of dengue and Zika, bite humans to obtain blood nutrients that support egg development. We report that, after a blood meal, female mosquitoes transition from a period of inactivity into active searching for egg-laying sites. Females with mature eggs show increased locomotor activity and a shift in circadian behavioral timing, leading to nocturnal humidity seeking and egg laying in an otherwise diurnal species. We show that the circadian clock gene cycle is critical for regulating this transition; its absence disrupts the timing of oviposition-related behaviors, causing reduced reproductive capacity when active site search is required. These findings suggest that, during egg development, circadian-clock-dependent behavioral reprogramming triggers nocturnal hyperactivity and oviposition site search, an essential process for mosquito reproduction and population viability.