Abstract Mosquitoes mostly mate in the context of swarms: to facilitate encounters with females, males form disordered aggregations over a visual marker, which serves as a positional reference. While the relevance of this visual marker for swarming activity has been largely addressed, it is still poorly understood whether, in addition to an individual’s response to environmental stimuli, insects in a swarm interact with each other, giving rise to a collective behavior. Here, with a dataset comprising three-dimensional trajectories of 30 laboratory swarms of different sizes (ranging from 80 to 400 mosquitoes), we investigate swarming behavior of Anopheles gambiae mosquitoes. We find that individual speed fluctuations are strongly correlated in space, meaning that mosquitoes in close proximity tend to display similar deviations from the group average, effectively flying at a similar speed, although no such correlation is observed in the flight direction. With a series of targeted tests, we prove that this correlation is not compatible with a random arrangement of individuals, nor with random fluctuations of individual speeds, thereby providing empirical evidence of an effective male-male interaction at play in our swarms.
Iacomelli et al. (Thu,) studied this question.