An ecological study of Banksiola crotchi Banks (Trichoptera, Phryganeidae) in Marion Lake, British Columbia

The life history and feeding relationships of larvae of the phryganeid caddisfly Banksiola crotchi Banks were investigated in Marion Lake, British Columbia. Eggs were laid on submerged vegetation in fall, larval growth was rapid in fall and spring, and adults were present from July to September. Larvae in instars two to four fed primarily on filamentous algae but in the final (fifth) instar, and to a lesser extent in the fourth, larvae were predaceous. Feeding rates of larvae were examined in the laboratory and the efficiency with which algae were used as food was investigated. A larval energy budget was constructed from field and laboratory data.