Water bug is the common name for true bugs (a specific type of insect) that spend most of their lives in the water. Most kinds of water bugs live in freshwater ponds, slow-moving streams, or pools of standing water. A few kinds of water bugs live in salt water.
Water bugs may be divided into five groups. The five groups are: (1) water boatmen, (2) backswimmers, (3) water scorpions, (4) giant water bugs, and (5) water striders (also called pond skaters). Most water bugs measure 1/8 to 13/4 inches (0.3 to 4.4 centimeters) long. Giant water bugs grow to 21/3 inches (6 centimeters) long.
Water boatmen have weakly developed mouthparts. They use their short forelegs to collect algae and other submerged food particles. All other water bugs have piercing and sucking mouthparts that enable them to feed on other insects, tadpoles, small fish, and salamanders. All water bugs except water boatmen can cause painful bites.
Water boatmen and backswimmers have long, flat, hair-fringed back legs that they use like oars when they swim. Backswimmers swim on their backs. They are able to swim up beneath their prey. They can stay underwater for several hours at a time by breathing from a bubble of air that envelops the abdomen. Water scorpions generally live on the bottom of ponds. A water scorpion has oval disks on its abdomen. The disks probably help the insect adjust to changes in water pressure and depth. Water striders have long, stiltlike back legs that enable them to dart across the water’s surface. They do not actually swim.
