Meeting Abstract
Bumblebees fly through cluttered environments while foraging for resources, and collisions with vegetation cause irreversible wing damage that accumulates with age. Wing damage has been linked to increased mortality in bees, but the mechanism behind this finding remains unclear. We examined the effects of wing damage on two major aspects of flight performance, stability and maneuverability. We filmed 25 Bombus impatiens flying with a 2.5 m/s headwind in three conditions: in unsteady, structured flow generated by an upstream cylinder, while maneuvering to track a laterally oscillating flower, and while maneuvering to track a flower in the presence of unsteady flow. Bees flew in all three conditions with intact wings, with asymmetric damage (~20% area clipped from one wing), and with symmetric damage (~20% area clipped from both wings). To quantify stability and maneuverability, we calculated translational and rotational body orientation, and evaluated flower tracking performance. Neither type of damage led to significant changes in stability during flight in unsteady flow, but maneuverability during tracking was reduced by asymmetric (but not symmetric) wing damage. When unsteady flow was combined with the challenge of tracking a flower, we did find an effect of wing damage on stability; however, in this case symmetric wing damage actually improved stability over intact wings, whereas asymmetric damage had no effect. These results suggest that reduced maneuverability caused by natural wing damage, which is typically asymmetric, could underlie the increased mortality found in previous studies. However, bees’ overall flight performance is impressively robust to wing damage, and symmetric damage can even provide stability benefits that may help compensate for the loss of force-producing wing area.
