Green Caddis Larva (Green Rock Worm)

The Green Caddis sometimes known as the Green Sedge is the Rhyacophila species of caddis flies and is one of the free-living types of caddis flies. What we mean by that is that they do not build cases that they carry with them. This characteristic makes them more available for the trout to eat. Although they can live in just about any habitat, they usually prefer faster moving water like the rifles and runs of the freestone mountain streams.

The larvae measure 11 to 18 mm long, and is most commonly referred to as the "rock worm" and this is the stage that the trout prefer to eat although they will also eat the pupa stage as well as the egg laying female adults. The larva stage can be fished throughout the entire season while the pupa stage is effective during the hatch and the adult stage is effective just after the hatch has occurred.

When these larvae are moving on the bottom of the freestone streams, they resemble the movements of an inchworm on the ground as they try to get down in between the rocks and gravel. Also, like the net spinners, they will sometimes suspend themselves from the rocks with a silk line. They are known as poor swimmers but none the less, they spend a good deal of time searching the bottom of streams for food. This is when they are vulnerable for the trout. 

While they tend to look like some of the net spinning larvae, they can be distinguished by having just one hard plate behind its head.