Caddisflies: Trichoptera

Most caddisfly larvae and pupae (PYU-pee), the life stage between larva and adult, are found in freshwater, but there are a few species that live on land or in the sea. The larvae of freshwater species usually live in cold clean flowing waters, but some species prefer warmer slower waters. They are very particular about water temperature and speed, dissolved minerals and pollutants, as well as the amount of sunlight. Several species can live together in a stream or river because each occupies habitats within the water that do not overlap. Predatory species wander about freely in the environment hunting for food animals, but many plant-feeding species live in protective cases built from pebbles, sand, or bits of vegetation from the bottom and held together with silk. A marine species from Australia and New Zealand spends part of its larval life eating tissues inside the body cavity of a living sea star (starfish). Later it leaves its host to build a case from seaweed.

The adults are usually active at night. They spend their days hiding in moist, cool habitats and are often found on vegetation growing along river banks.