Learn/Fly Box/Nymph/Green Rock Worm
GR
Nymph

Green Rock Worm

Apple-green fast-water predator
Trout · GraylingDeep

The bright apple-green free-living (caseless) Rhyacophila larva of fast water — actively predatory, highly available, a superb dead-drift nymph.

Fish this when

In fast, well-oxygenated freestone water at any time of year, dead-drifted tight to the bottom as a confidence searcher when nothing's rising.

Why it works

Rhyacophila larvae hunt and drift more than most caddis, so the vivid apple-green colour combined with genuinely high natural availability makes this a fly trout already expect to see.

Naturals it imitates
free-living Rhyacophila larva (bright green)
Typical zone & fishable range
usually
Surface
Film
Subsurface
Deep
Setup sensitivity: medium
Hook range#12–14
Quick facts
Tying difficulty
Beginner-friendly