Evidence of a Net-spinning Caddisfly Larvae (order Trichoptera, family Hydropsychidae): Rather than build a protective case of small stones or other materials, these interesting caddisflies build a home of silken thread. It’s not only used to provide protection, but to catch dinner. The larvae feed on algae, diatoms, crustaceans, and immature aquatic insects that are swept into their net by the current. Photo by Christine Morris on 8/1/18 near Hole in the Wall campground.