Meeting Abstract
Insect wings bend and twist during flapping flight, and the aerodynamic consequences of these passive deformations have been the focus of intense research in recent years. Both computational and experimental studies have found that wing flexibility enhances aerodynamic force production in a range of insects, including locusts, moths, hoverflies, and bumblebees. However, all of these studies have focused on steady locomotion in smooth flow or still air, whereas in reality, insects flying in natural environments rarely encounter steady airflows. We have noted previously that the wings of bumblebees appear to undergo larger passive deformations during flight in turbulent air as compared to smooth flow, suggesting that wing flexibility may play a role in stability enhancement and/or gust mitigation. To test this hypothesis, we flew bumblebees (Bombus impatiens) in a wind tunnel modified to generate turbulent airflow, and examined the effects of wing flexibility on flight performance by artificially stiffening a single flexible vein-joint that contributes to chordwise wing flexibility, using an in vivo micro-splinting technique. We tracked three-dimensional flight trajectories and compared lateral and rotational body motions in bees with unstiffened and stiffened wings. Our results reinforce the challenge that turbulent airflow poses to insect flight stability, and suggest that wing flexibility may play an important role in enhancing flight performance beyond its effects on force production.
