The Bead Head Green Caddis Larva is a killer Deschutes fly during late winter and early spring. During this time period dozens of these flies are shipped from our store.
In rivers, Caddis larvae can be divided into three basic types; case builders, net spinners and free-living roamers. All caddis larvae are subject to periodic behavioral drift cycles. This is how populations disperse themselves. Both free-living and net spinning caddis larvae can produce a silken strand very much like spider web. To move down stream they will hook their line to a rock and then rappel themselves down stream. They are often dangling in the current for long periods. During these periods entire populations can be exposed to trout which will key on them exclusively. Caddis larva can be extremely vulnerable to catastrophic drift caused by high water, which can sweep them from the bottom.
Case builders construct tubular homes from small stones or vegetable matter. Each specie has a defining way that it constructs its cases. Some will be smooth, other are rough. Some are square in cross section, others are round. When cased caddis larva of most species migrate, they simply turn loose of the river bottom and let the current sweep them down stream. The case tumbles and rolls. The larva is often extended from the case waiting to grab onto the riverbed. Usually the dark head, legs and the light thorax are highly visible to the trout. They "key" on these dark and light bands.