Wire is used to build the body of this caddis fly nymph larva imitation. These types of caddis live in fast cold water which allows them to absorb oxygen through their skin. Fish this Shaggy Wire Caddis fly nymph in the riffles and swim it to the surface. These larva are very strong swimmers and are not generally found in slower pools. Color, Green.Size: 14, 16, 18.