Video: Beetle water skis on the surface of ponds

Many insects fly through the air or dive in the water. But when a water lily beetle (Galerucella nymphaeae) sees a tasty plant on a pond’s surface, it doesn’t soar or swim. It water skis. It’s not the only insect that makes its living along the surfaces of ponds, but unlike many other surface-dwellers, the waterlily beetle has fully developed wings and can fly through the air when it wants to. It also has special adaptations that keep it from lifting off into the air as it zips across the water, researchers report today in the Journal of Experimental Biology. The beetle’s legs are covered in tiny hairs that repel water -- but its claws are smooth, allowing the insect to anchor itself to the pond surface as it beats its wings. This unique way of flying requires the beetles to drag their claws through the water and creates chaotic ripples that make flight even less efficient than flying through the air. So why do it? Researchers say that finding a floating food plant is easier for the beetle when it only has to search in two dimensions—which might outweigh the extra work required to skim the surface.