Meeting Abstract
Landing is a critical component of insect flight. In nectivorous insects such as bumblebees (Bombus impatiens), landing must be performed hundreds to thousands of times daily, and thus represents a key component of foraging behavior. Previous studies have shown that the visual system triggers preparatory landing behaviors, such as deceleration and leg extension, and recent work suggests that landing is regulated by a simple, yet robust, universal control strategy, whereby the rate of image expansion is held constant to regulate flight speed during the approach. However, to our knowledge there has been no research investigating whether insects use this same strategy in the presence of wind, a ubiquitous challenge for insects flying in natural environments. We investigated the landing behavior of bumblebees in the presence and absence of wind, when landing on flowers that were aligned with or perpendicular to the flow. We filmed bees approaching and landing on real flowers in a wind tunnel using high-speed videography, and tracked body kinematics using a modified version of BEEtag, an open-source image-based tracking system. Our results show that bees’ approach paths to flowers vary highly in still air, but become more restricted in the presence of wind, irrespective of flower orientation. In still air, flight speed declines gradually during the approach, as predicted by previous studies. However, in the presence of wind, flight speed remains constant throughout the approach and landing, peak acceleration is higher at touchdown, and body stability is reduced. These findings suggest that wind has a strong influence on landing strategies in insects, with important implications for both the design of flying micro aerial vehicles and the ecomechanics of insect flight in natural environments.
