Walk on water: Fluid dynamics of microvelia locomotion

Microvelia water striders are semiaquatic insects that live in low flow streams. They walk on the water surface through an alternating tripod gait. In nature, these insects can be found on land and water, yet we discovered adult microvelia are faster on the surface of water than on land. In this talk, we will discuss how the microvelia are able to use the alternating tripod gait to locomote better on water than on styrofoam. When calculating the Reynolds, Bond, and Baudoin numbers, we show the forces responsible for locomotion. We hypothesize that they can achieve these faster speeds due to the surface properties that reduce the shear stress and allow them to deform the surface of the water. Through particle image velocimetry and schlieren imaging we will obtain the forces used for propulsion and determine the shear stress observed on the legs of the microvelia. We will then compare how these forces change with body size to scale performance among age classes.