Trichoptera

The caddisflies, or Trichoptera, are a group of s with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders  and  on the basis of the adult mouthparts. Integripalpian larvae construct a portable casing to protect themselves as they move around looking for food, while Annulipalpian larvae make themselves a fixed retreat in which they remain, waiting for food to come to them. The affinities of the small third suborder are unclear, and  suggests it may not be. Also called sedge-flies or rail-flies, the adults are small -like insects with two pairs of hairy membranous. They are closely related to the (moths and butterflies) which have scales on their wings; the two orders together form the superorder.

The aquatic e are found in a wide variety of habitats such as streams, rivers, lakes, ponds, spring seeps and temporary waters (s). The larvae of many species use to make protective cases, which are often strengthened with gravel, sand, twigs, bitten-off pieces of plants, or other debris. The larvae exhibit various feeding strategies, with different species being predators, leaf shredders, algal grazers, or collectors of particles from the water column and. Most adults have short lives during which they do not feed.

In, artificial flies are tied to imitate adults, while larvae and pupae are used as bait. Common and widespread genera such as ' and ' are important in the sport, where caddisflies are known as "sedges". Caddisflies are useful as s, as they are sensitive to and are large enough to be assessed in the field. In art, the French artist has created works by providing caddis larvae with small grains of gold and precious stones for them to build into decorative cases.