Meeting Abstract
Flying insects regularly forage in complex, three dimensional environments in a wide range of wind conditions. This behavior necessitates a robust strategy for successfully tracking and landing on targets such as flowers in variable wind conditions. While general strategies for visually guided landing have been described in honeybees, the mechanical sequence of landing in bees and particularly the effects of wind speed on landing performance have received relatively little attention. Here, we study mechanical strategies for landing in 0, 1.5, and 3.0 m/s laminar and turbulent flow conditions. Using high-speed videography, we tracked landing behavior of Bumblebees (Bombus impatiens) using four calibrated high-speed cameras filming at 5000 frames per second. We quantified translational and rotational kinematics of the body as well as wing and leg motions from the time of approach until wings stopped beating. In agreement with work on landing behavior in flies, we found that all bees extended legs roughly 60-70 ms before touchdown. Surprisingly, we found that in low-speed trials, all bees contacted the flower first with either their head or antennae before the legs made contact with the flower. However, in high-speed flow trials it was more common for bees to first contact the flower with their legs rather their head or antennae. This suggests that in addition to preparing for landing, leg extension in bumblebees could serve a “bet-hedging” role, allowing bees to increase the potential contact area for landing. Overall, these results show that bumblebees use a landing strategy that is robust to variable flow conditions, which has important implications for understanding how flying insects navigate and land in challenging, variable flow.
