Rather than building a case to live in, Hydropsyche Caddis build a shelter out of gravel and plant debris that they attach to the sides of rocks. These "net spinners" need a steady current to bring them food. They prefer moderate to large sized streams with warmer temperatures, somewhat slower currents, and smaller substrate - The Missouri River Below Holter Dam.
Like all caddis, Hydropsyche's pass through four stages of development: egg, larva, pupa, and adult. The exact timing of the emergence can be difficult to predict because of the variety of species and habitats. Hatches are sparse in early spring. The first large emergences on the Missouri River occur from late May through June and most of July.