Mosquitoes escape looming threats by actively steering into the bow-wave induced by the attacker

Summary

To detect and escape a threat, night flying insects must rely on other senses than vision alone. Here we study how anthropophilic malaria mosquitoes can escape a swatting hand in the dark using high-speed videography and numerical simulations. We show that these night flying mosquitoes escape looming objects by using the object-induced airflow in two ways. They first actively steer into the bow-wave produced by the attacker, and then passively travel with this bow-wave away from the attacker; these two aspects explain two-thirds and one-third of their escape accelerations, respectively. Thus, flying mosquitoes being attacked in the dark rely both on airflow-sensing to trigger their escape, and on attacker-induced airflow to maximize their escape performance. Similar escape strategies are probably common among small lightweight insects