Trichoptera (Caddisflies)

Caddisflies, or Trichoptera, are an order of aquatic insects known for the case and retreat-making behavior of the larval stage. They are found in lakes and rivers around the world. Larvae are important in nutrient cycling and energy flow in aquatic ecosystems. They are used as biological indicators of water quality. Larvae use silk to build cases from a wide variety of materials, including sand grains and plant material. Case morphology is very diverse. Cases afford protection and enhance larval respiration. Larvae in other groups use silk to spin fine-meshed nets to filter water of fine organic material and other food. Another group make no larval structure and are free-living predators. Adults are secretive, largely nocturnal, and short-lived. They resemble small moths, but fine hairs, instead of scales, cover their wings. There are 45 families, distributed in three suborders, Spicipalpia, Annulipalpia, and Integripalpia, and about 13. 000 described species. Tropical faunas are especially diverse with many new species being discovered.