Insects living at the air/water interface are subject to capillary phenomena due to surface tension. They use these phenomena to detect preys and conspecific individuals, in particular with capillary waves. Gyrinidae (Coleoptera) which I choose as a model, are supposed to use echolocation on surface water using the waves they generate.

My purpose is to study wave propagation and the echolocation system used by whirligig beetles. I characterized capillary waves produced by Gyrinus substriatus, a primordial step for the study of echolocation. I fond that whirligig beetles have three different types of leg kinematics for swimming, two at low speed and one at high speed. Each type produces a particular pattern of speed and waves. I could also highlight that low and high speeds correspond to speed ranges minimizing resistance forces (fluid resistance and wave resistance). I am currently testing experimentally if whirligig beetles use echolocation for detecting non-moving objects on water surface. I study also another kind of perception, the detection of static deformation of the water surface around objects (meniscus) which could be complementary to echolocation.

I am deeply interested in physical ecology of aquatic insects and particularly in the importance of

Gyrinus substriatus producing waves in an aquarium.