CDC Cripple, PMD
"Cripple" patterns represent mayflies that are either just emerging or that got stuck in the shuck while emerging. In either case, the insect isn't going anywhere soon. Trout recognize this vulnerable condition and feed eagerly on cripples when they see them. When you're confronted with a blizzard hatch, where your fly is one small speck among hundreds or thousands of natural insects, a cripple pattern is a great way to induce trout to take your fake.
CDC cripples are particularly useful on spring creeks and slow water.
This dressing imitates a pale morning dun mayfly. Different size and color choices will imitate other mayfly 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.
HOOK: TMC 100, sizes 16-18
TAIL: yellow woodduck flank and brown Z-lon. Keep it sparse.
BODY: Yellow rabbit
WING: White CDC on top, yellow Z-lon on sides
THORAX: Pale yellow rabbit