Caddisflies constitute the insect order Trichoptera in which some 10,000 species are now known in the world, including about 1400 in Canada and the United States. This book is a comprehensive reference about caddisflies for freshwater biologists, entomologists, and students in those fields of study. The underlying theme of the book is that the effective roles of caddisflies in the flow of energy and nutrients supporting freshwater ecosystems is due largely to extraordinary diversification in larval architecture. The book is concerned with behavioural ecology, evolutionary history, biogeography, and biological diversity of caddisflies.