Cicadas True Bugs and Relatives: Hemiptera

Physical characteristics: The giant water bug is the largest true bug in the world, with adults reaching 4.5 inches (115 millimeters) in length. The body is uniformly pale to dark grayish brown. The forelegs are large, powerful, and adapted for grasping prey. The middle and hind legs are flattened for swimming. Males and females are similar in both size and appearance. The larvae resemble the adults but are smaller and lack fully developed wings.

Giant water bugs kill their prey with digestive saliva that turns the victim's tissues into liquid. The fluid is then sucked up with short, beaklike mouthparts. They will successfully capture and kill prey that is larger than they are. (Illustration by Katie Nealis. Reproduced by permission.)

Geographic range: Giant water bugs are found from the West Indies south to northern Argentina.

Habitat: This species lives on submerged plants growing along the margins of pools and lakes.

Diet: They eat aquatic insects, fish, frogs, and tadpoles.

Behavior and reproduction: Giant water bugs kill their prey with digestive saliva that turns the victim's tissues into liquid. The fluid is then sucked up with short, beaklike mouthparts. They will successfully capture and kill prey that is larger than they are. Adults breathe by capturing air under their wings. Larvae rely on patches of short hairs underneath their bodies to trap a layer of air. Adults fly to different bodies of water at night and are often attracted to lights.

Clusters of dozens of eggs are laid on twigs above the water surface and are guarded by the male until they hatch. The larvae disperse at hatching.

Giant water bugs and people: Giant water bugs prey on young fish and may seriously reduce production at fish farms. Bites are very painful but infrequent.

Conservation status: This species is not endangered or threatened. ∎