Caddisflies are an ecologically diverse and important group of freshwater insects. Their larvae are sensitive to pollution and for this reason are used as indicators of water quality. Oxygen concentration and water velocity are important to larvae, as is the chemical content of the water. Caddisflies live most of their lives in the larval state, depending on aquatic habitats to mature to adulthood.
Caddisflies gets creative in the ways they shield themselves from predators. Larvae construct cases, or homes, out of silk woven with sand grains, fragments of wood or twigs, stones, and other materials from their surroundings.
Check out some images below from freshwater insect photographer, Jan Hamrsky:
Caddisfly larvae spend up to two years in their cases before becoming adults. The cases are so pretty that some artists encourage caddisflies to spin their silk around semiprecious stones so their cases can be used as jewelry.
CWEP loves to use activities about macroinvertebrates to teach about clean water! We sometimes find caddisflies in streams, and at tabling events we let participants craft their own caddisflies.
Check out some images from CWEP @ Carrboro Day: “Make your own Caddisfly” craft!