Flow underneath the wing of a honey bee locomoting on a water surface

In our previous studies, we observed honey bee’s locomotion at the air-water interface. Their ventrally wetted wings beat at high frequency (30-220 Hz), which propel them forward. Using the kinematics of body we measured average thrust generated by the wing to be O(100 μN). To understand the thrust generation by the beating wing, we constructed a mechanical model that can mimic the bee’s wing kinematics. The flow under the wing was quantitatively measured using digital particle image velocimetry. The flow field shows that the wing is pumping the fluid underneath the wing backwards, consistent with the forward thrusting by the bee.