Caddisflies
Last Review/Updated: May 31, 2002
Caddisflies
are one of the largest groups of aquatic insects. Their closest relatives
are butterflies and moths, and adult caddisflies look like moths. There
are about 275 species of caddisflies in Alberta. Caddisfly larvae live
in every kind of water habitat, from cold mountain streams to small
and temporary prairie puddles. A caddisfly may lay several hundred
eggs during the summer. After hatching, the larvae build and live in
cases covered with small sticks or stones. As they grow, the cases
are made longer and wider. When danger threatens, the larvae retreat
inside the cases. They feed on small animals and plants, and overwinter
as young larvae.
The
larvae turn into pupae the next summer. The pupae float to the surface,
and the adults emerge and fly away. Caddisfly larvae are an important
fish food. The best trout streams have many larvae on their bottoms.
