Unlike mayflies, adult caddis are not especially vulnerable to trout when they first hatch. However, they are long-lived (compared to mayflies), and often fall or are blown onto the river. So adult imitations work well any time caddis have been hatching.
Abdomen and wing colors are chosen to match the natural insect. See the caddis pages for colors/sizes of different caddis species.
How to Fish
Do NOT dress the fly with floatant! CDC flies should be fished au natural. When a fly no longer floats well, put it in a small container of powdered descicant, such as Dry Shake, and shake it up. This removes the moisture, and you're ready to cast again.
Use standard dry fly presentations. When fishing in rivers, the best places are usually near the bank, especially downstream or downwind from overhanging trees or other vegetation.
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