CDC Emerger
Nature's floatant meets the most critical feeding window.
The CDC Emerger exploits the natural oil in CDC (cul de canard) feathers to hang a sparse mayfly emerger perfectly in the surface film. The loop wing and trailing shuck create an exact imitation of a mayfly struggling to emerge from its nymphal shuck — the moment when trout feed with the least caution.
History & Lore
CDC patterns originated in the Jura Mountains of Switzerland and France, where anglers discovered that the preen gland feathers of ducks naturally repelled water. CDC emerger designs became widespread in European fly fishing by the 1980s and reached American tyers by the 1990s.
Variations
Klinkhammer-style CDC
Curved shank for a deeper body hang in the film.
CDC Loop Wing Emerger
Exaggerated loop wing for more visible profile.
Snowshoe Hare Emerger
Snowshoe rabbit foot replaces CDC for durability.
How to Fish It
Fish the CDC Emerger dead drift in the surface film during mayfly hatches. It is particularly effective when trout are refusing conventional dries — they're likely feeding on emergers stuck in the shuck. Dry the CDC between fish by false casting, never by squeezing.
When to Use
During any mayfly emergence, especially when trout are bulging or sipping rather than splashing. Critical pattern for BWO, PMD, and Callibaetis hatches.
Materials
- Hook
- TMC 2488, #16-22
- Thread
- Uni 8/0, olive or tan
- Shuck
- Z-lon or Antron yarn
- Body
- Fine dubbing, olive or tan
- Wing
- CDC feather, looped
Tying Video
Tying Steps
Tie in a few strands of Z-lon or Antron yarn at the bend for a trailing shuck.
💡 The shuck represents the nymphal exoskeleton the emerging mayfly is shedding.
Dub a slim body of fine dubbing from bend to 70% of the shank.
💡 Match body color to the natural — olive for BWOs, tan for PMDs.
Select a CDC feather and tie it in by the tip at the thorax position.
💡 One quality CDC feather is better than multiple poor ones.
Loop the CDC feather forward to form a bubble wing over the thorax area.
💡 The CDC loop should suggest a crumpled, emerging wing.
Dub a slightly fuller thorax, whip finish, and trim any stray CDC fibers.
💡 Never apply floatant to CDC — it destroys the natural oils.
Frequently Asked Questions
What size CDC Emerger should I use?
The CDC Emerger is most commonly tied in sizes 16–22. During any mayfly emergence, especially when trout are bulging or sipping rather than splashing. Critical pattern for BWO, PMD, and Callibaetis hatches.
What does a CDC Emerger imitate?
The CDC Emerger primarily imitates mayfly emergers, BWO emergers, PMD emergers, Callibaetis emergers. Fish the CDC Emerger dead drift in the surface film during mayfly hatches. It is particularly effective when trout are refusing conventional dries — t
What materials do I need to tie a CDC Emerger?
Key materials include: Hook, Thread, Shuck, Body, Wing. Tie a Z-lon trailing shuck, dub a sparse body, and loop a CDC feather over the thorax as a wing that
How do you fish a CDC Emerger?
Fish the CDC Emerger dead drift in the surface film during mayfly hatches. It is particularly effective when trout are refusing conventional dries — they're likely feeding on emergers stuck in the shuck. Dry the CDC between fish by false casting, never by squeezing.
Pattern Details
- Category
- Emergers
- Sizes
- 16–22
- Colors
- Olive, Gray, Tan
- Hook Styles
- Scud/emerger hook, Standard dry fly
- Imitates
- mayfly emergers, BWO emergers, PMD emergers, Callibaetis emergers
- Water Types
- tailwater, spring creek, lake
- Origin
- European tradition, Jura Mountains, Switzerland/France
Target Species
Pattern Details
- Category
- Emergers
- Sizes
- 16–22
- Colors
- Olive, Gray, Tan
- Hook Styles
- Scud/emerger hook, Standard dry fly
- Imitates
- mayfly emergers, BWO emergers, PMD emergers, Callibaetis emergers
- Water Types
- tailwater, spring creek, lake
- Origin
- European tradition, Jura Mountains, Switzerland/France