The Rock Worm is a realistic caddis larva imitation that excels in fast-moving streams and freestone rivers where caddisflies thrive. With its slender profile and natural olive-to-green coloration, this pattern mimics the free-living caddis larvae often found clinging to rocks near the riverbed. It’s a go-to fly when trout are feeding subsurface, particularly in spring and early summer when caddis activity peaks.

Tied with a segmented body and often finished with a beadhead for quicker sink, the Rock Worm is designed to ride low in the water column. Its natural movement and color make it a deadly pattern when dead-drifted near the bottom where trout expect to find protein-rich aquatic insects.

To fish the Rock Worm effectively, present it with a tight-line euro nymphing setup or under an indicator in a two-fly rig. Drift it through deep runs, riffles, and pocket wateranywhere trout are rooting for food along the streambed. Pair it with an attractor nymph above or fish it solo when you want to match the hatch with precision.