Stonefly nymph (Genus: Stenoperla) Stenoperla prasina
Species: S. prasina
Binominal name: Stenoperla prasina
Common name: Green stonefly
Stenoperla prasina is a member of Large Green Stoneflies (Genus Stenoperla). The nymph life span is about 1 year.
“Early instar nymphs of S. prasina feed on diatoms and algae but later become carnivorous feeding mainly on the nymphs of mayflies, Deleatidium, Coloburiscus, Ameletopsis, and Oniscigaster, but also prey upon blepharicerids, chironomids, other small stoneflies, fish eggs and even upon their own species. Nymphs come out at night and actively hunt the substratum. They will not eat dead food, but must have living prey, which is killed and devoured on the spot” (Helson 1934, Winterbourn 1974).