Historic Illinois - Insect Adaptations

Many animals have adaptations for survival in specific environments. Some insects are specially adapted for life in, or on, the water.

 

Some Insects Walk on Water
The legs and underbody of the water strider (Gerris nebularis) are covered with fine, waxy hairs that repel water. The legs and hairs spread the strider's weight so it bends, but doesn’t break, the water's thin elastic surface film. The water strider uses its front legs to grab prey. Its middle legs are used to move over the water, and the hind legs steer.

 

Some Insects Swim Underwater
The giant water bug (Lethocerus griseus), water boatman (Hesperocorixa kennicottii), and water scavenger beetle (Hydrophilus triangularis) have paddle-like legs for swimming. Leg hairs increase surface area and enhance their paddle-like function. Streamlined bodies help these insects move quickly through the water.

 

Some Insects Breathe Underwater
Hellgrammites (Corydaluss cornutus) and mayfly nymphs (Heptagenia flavescens) and ebony jewelwing nymph (Calopteryx maculata) have gills that help them get oxygen from the water.

The giant water bug has a different strategy. It carries a supply of fresh air by trapping an air bubble under its wings. The water boatman and water scavenger beetle have water-repellant hairs that trap a film of air against the body. The film of air acts like a gill, taking in oxygen and letting carbon dioxide escape into the water.