SM Link


  • Order Trichoptera
  • Most diverse groups of aquatic insects in North America
  • Over 1,350 species and 22 families recognized
  • Many stream and water quality specialists recognize caddisflies as valuable indicators of stream health
  • EPT OR Ephemeroptera, Plecoptera, Trichoptera, three orders of insect groups known for a strong indication of stream (and watershed) health

Back to Learn More About Critters


  • Caterpillar-like larvae with feathery gills
  • Pair of prolegs on the end of the abdomen with a hook on each proleg
  • Caddis means house or home
  • Many make elaborate cases out of small stones, sand, twigs and/or plant material


  • Resemble moths
  • Two pair of hairy, membranous wings that form triangular “roof” over their body at rest


Caddisfly feeding groups is determined by the type of case they make. Given their high diversity it is not surprising that caddisflies have representatives in most feeding groups.

  • Cases constructed from sand or small pebbles are often grazers and collectors, feeding on diatoms and other fine organic material.
  • Caddisflies that use plant material to make their case are likely shredders, feeding on coarse organic material such as leaves and twigs.
  • Net-spinning caddisflies create silk nets to filter food from the stream.
  • Free-living caddisflies are predaceous and feed upon smaller invertebrates.


Species diversity is highest in rivers and streams, but can be found in lakes, ponds, and wetlands


This diverse order is found throughout South Dakota, however Black Hills streams have the highest diversity of caddisflies in South Dakota