Mosquito sound communication: are male swarms loud enough to attract females?

Authors: FEUGERE, L - University Of Montpellier; GIBSON, G - University Of Greenwich; Manoukis, Nicholas; ROUX, O - Health Sciences Research Institute

Submitted to: Journal of the Royal Society Interface
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2021
Publication Date: 5/18/2021
Citation: Feugere, L., Gibson, G., Manoukis, N., Roux, O. 2021. Mosquito sound communication: are male swarms loud enough to attract females?. Journal of the Royal Society Interface. 18(177). Article 20210121. https://doi.org/10.1098/rsif.2021.0121.
DOI: https://doi.org/10.1098/rsif.2021.0121

Interpretive Summary: This study examines questions about mating swarms of disease-transmitting mosquitoes. The idea has been raised that females of different (but similar) species might be able to detect and distinguish between swarms of different types of males from many meters away based on sound. We tested whether that might be possible based on recordings of swarms in nature, female and male behavioral responses to swarm sounds in the lab, and calculations on the sizes of swarms in nature, and conclude that females can not detect swarms of males from any considerable distance.

Technical Abstract: Given the unsurpassed sound-sensitivity of mosquitoes among arthropods and the sound-source power required for long-range hearing, we investigated the distance over which female mosquitoes detect species-specific cues in the sound of station-keeping mating swarms. A common misunderstanding, that mosquitoes cannot hear at long-range because their hearing organs are ‘particle velocity’ receptors, has clouded the fact that particle-velocity is an intrinsic component of sound whatever the distance to the sound source. We exposed free-flying Anopheles coluzzii females to pre-recorded sounds of male An. coluzzii and An. gambiae s.s. swarms over a range of natural sound-levels. Sound-levels tested were related to equivalent distances between the female and the swarm for a given number of males, enabling us to infer distances over which females might hear large male-swarms. We show that females do not respond to swarm sound up to 48 dB SPL and that louder SPLs are not ecologically relevant for a swarm. Considering that swarms are the only mosquito sound-source that would be loud enough to be heard at long-range, we conclude that inter-mosquito acoustic communication is restricted to close-range pair interactions. We also showed that the sensitivity to sound in free flying males is much enhanced compared to that of tethered ones.