Order Trichoptera

Trichoptera, or caddisflies, are an order of aquatic insects occurring around the world in rivers, streams, and lakes. About 15,000 species are known. The aquatic larvae use silk to construct cases in which they reside or to spin silken nets to capture food suspended in the water column. The adults, with the body and wings covered with fine hairs, are crepuscular and resemble small moths. Larvae are important components of aquatic food webs. Most are intolerant of pollution and serve as biological indicators of water quality. This chapter provides an overview of the geographical, morphological, and ecological diversity of caddisflies. Aquatic respiration, osmoregulation, diapause, and other physiological adaptations are reviewed. The literature on general aspects of life history, ecology and behavior, such as adult emergence, mating behavior, egg laying, predation, construction behavior, food and feeding, drift, and production is reviewed. The effect of climate change and other human impacts on the diversity and distribution of caddisflies is discussed. Finally, methods for collecting, preparing, and observing immature stages and adults for scientific study are presented.