McKenzie Caddis

Larvae

(body length approx. 2.7 cm)

The above caddis larva was found in a riffle in early March. These can be found in the McKenzie, usually in riffles and faster water. They live in their larval form for two years, and the one pictured above is definitely in its second year. They are voracious predators, and generally don't enjoy being photographed. This particular bug would bite a toothpick, and hold on well enough to be picked up out of the water... Unlike many caddis, they are essentially free living, and do not make a case to live in. They do have the ability to spin silk, however, and make crude nets to capture unlucky bits of food passing by in the current. Because they are free living, they are frequently available to trout when dislodged, or drifting to new territory.

Pupae

(body length approx. 0.9 cm)

The McKenzie Caddis pupate by spinning a silk cocoon in the gravel on the bottom of the stream, usually starting in late May. They will then, like most caddis, start building up carbon dioxide (?) bubbles under their skin, and eventually float up to the surface to hatch as adults. This is one of the best times to fish an imitation of them, as trout will enthusiastically chase them up to, and even past, the surface of the water.

Space Reserved for Photo of Adult

dmason@zebu.uoregon.edu