March, 2004

Water Strider

Our ponds attract a number of insects, including the delightful water strider (Aquarius remigis). Water striders have several common names as well, including pond skaters and Jesus bugs. They are one of the most recognizable insects, with their long legs and 3/4 inch bodies. Only a portion of the adults have wings, but I've noticed that most of the largest ones in our ponds do. They probably fly to this location in the first place.

Water striders are predators and catch insects on the water surface. They don't seem to be too cannibalistic as I've watched entire broods grow from newly hatched nymphs to mating adults on our small ponds. Like other true bugs, water striders use a tube-like mouth to suck the juices from their prey. When they are feeding, they sometimes push their bodies up higher to accommodate keeping the insect below them out of the water.

The most striking thing about these bugs is their ability to glide effortlessly over the water. Tiny hairs on their legs make it possible for their lightweight bodies to ride on top of the surface tension. If the hairs get wet, they will lose their repellent properties and the insect will sink. Water striders don't do well if they can't find shelter during heavy rains, and I've occasionally found them dead after storms.

Although there is no current in our ponds, water striders also live on rivers and streams. They seem to have an instinctive drive to swim upstream. During very heavy rains, our backyard floods, and the water striders move in the direction from which the water is flowing. One time, several of the insects ended up in our smaller pond (upstream from the large one), and other times they simply get lost in the grass far from the ponds.

Water striders require open water but avoid large expanses. They easily fall prey to fish and so usually hug the shore or remain near vegetation. However, they still need enough space to be able to zip around on the water without having to constantly climb over emergent plants. When our ponds get too grown in, the water striders vacate the premises.