Flight-tone mediated circadian control of audibility in mating swarms of Anopheles mosquitoes

Mating swarms of malaria mosquitoes form every day at sunset throughout the tropical world, they typically last less than 30 minutes. Activity patterns must thus be highly synchronized between the sexes. Moreover, males must be able to identify the few sporadically entering females by detecting the females faint flight tones. We here show that the Anopheles circadian clock ensures a tight synchrony of male and female activity and -importantly - also retunes the males acoustic detection system: by lifting their own flight tones at dusk, males actively enhance the audibility of females. The reported phenomenon of harmonic convergence is a random by-product of the mosquitoes flight tone variance. Intriguingly, flight tones of individual mosquitoes occupy narrow -partly non-overlapping-frequency ranges, suggesting that the audibility of individual females varies across males. One Sentence SummaryMale mosquitoes sharpen their hearing at sunset.