Rock Worm Fly

Rock Worm

A subsurface pattern that mimics caddis larvae, a prevalent food source for trout and other bottom feeding fish species.

How it's tied

The Rock Worm is tied on a curved or straight nymph hook, with materials selected to replicate the characteristics of natural caddis larvae. The body is typically formed using a fine dubbing, often in colors that match local caddis populations, such as green, tan, or brown.

A rib of fine wire or contrasting thread is wound up the body, giving the impression of the segmented structure of a caddis larva. The thorax area can be built up slightly with extra dubbing, and some tiers may include a bead at the head for additional weight and flash.

One of the defining features of the Rock Worm is the soft hackle collar, typically made from a partridge or hen feather. This provides lifelike movement underwater and simulates the tiny legs of a caddis larva. Some of the patterns don't have this, but instead use other materials to simulate the legs, like the one you see in the picture above.

What it mimics

The Rock Worm is specifically designed to mimic caddis larvae, a crucial part of the diet for trout and other freshwater fish. The segmented body, soft hackle collar, and realistic colors help the fly mimic the size, shape, and behavior of natural caddis larvae.

Where it's used

The Rock Worm can be effectively fished any freshwater, particularly in areas where caddis populations are high. It can be fished alone or as part of a multi-fly setup, under an indicator or euro nymphing rig.

Fly tying video for the Rock Worm

Fish you can can fly fish for with the Rock Worm

Brown Trout


Rainbow Trout

Caddisflies (Latin: Trichoptera)

The Rock Worm mimics one or more species from the insect order Caddisflies

Latin: Trichoptera

Caddisflies are aquatic insects, closely related to moths, with larvae that construct protective cases from various materials found in their environment.

Read more about Caddisflies

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