Salmonfly

Pteronarcys californica

Pteronarcidae

StoneflyHook #4-830-50 mm body

Peak activity

JanFebMarAprMayJunJulAugSepOctNovDec

Nymph

Flattened body with two tail cerci; found under rocks in riffles.

Adult

Four wings folded flat over the back; long antennae.

Habitat & hatch

Found in rivers and tailwaters, most commonly in riffles and bank. Nymphs under rocks; adults crawl out on banks and boulders. Often associated with cobble and boulder. Nymphs crawl to rocks and banks to emerge; adults often found on riparian vegetation.

Timing

Individual emergence windows typically last 4 to 11 days. Strongest surface activity occurs around the morning, and the afternoon.

Sources

Townsend & Pritchard 1998 — Crowsnest River, Alberta.