Caddisflies

Caddisflies are insects in the order Trichoptera. The moth-like adults and the mostly aquatic larvae are different stages of the same life cycle.

Most have long, threadlike antennae and hairy wings held like a tent over the body at rest. They often look like small, brown or grey moths.

Most live in freshwater, including streams, rivers, ponds and lakes. Different species occupy flowing water, still water or temporary pools.

No. Many build cases from silk, sand, stones or plant fragments. Others spin fixed nets or retreats, and some live without a portable case.

Diets vary. Some graze on algae or eat decaying leaves and other organic material; others filter particles from the current or prey on small aquatic animals.

Many feed little or not at all during their brief adult lives. Some can drink water or nectar through their reduced mouthparts.

They pass through egg, larva, pupa and adult stages. After growing as larvae, they pupate, usually in water, before the winged adults emerge.

Their community helps scientists assess stream conditions, but sensitivity varies among groups. Finding a caddisfly alone does not prove that the water is unpolluted.