How do Water Striders Walk On Water?
Their main body, known as the thorax, is thin and oblong, averaging between 1.6 and 3.6 mm in length. Each leg is covered in thousands of microscopic hairs that are in turn covered by even tinier grooves. These hairs and grooves enable water striders to glide atop water effortlessly, as they essentially trap air and hydrophobic molecules that enable these insects to resist the water’s surface tension. These cool, uniquely adapted hydrophobic legs allow the water strider to move at a pace of over a meter per second. To put this in perspective, a human would have to swim over 400 miles per hour, or 9 miles per second.
What do Water Striders Eat?
Water striders are beneficial predatory insects, feeding on both live and dead aquatic insects that they come across, and occasionally small, freshly hatched tadpoles. Most notably, prey species include mosquito larvae and adults, dragonfly larvae, and midges, though they’ll eat just about any insect or larva that they are able to find, be it live or something dead that’s dropped into the water.
Their four longer legs quite adeptly sense vibrations in the water, which they will either head toward if the ripples are small enough to be prey, or dart away from if they’re large enough to be from a threat. Their two short, strong front legs grab onto prey, while a hollow straw-like mouthpart pierces the prey and essentially sucks them dry. Luckily, this mouthpart is too weak to penetrate humans, fish, or anything other than soft-bodied insects, nor do they show any interest in attacking non-insect organisms.
Water striders can be viewed as a relatively important species, as they not only feed on pest species like mosquitos, but also provide food for other organisms. Fish, birds, frogs, turtles, and some other aquatic insects all feed on water striders.