Here is the fly pattern sheet for the Blue Wing Olive CDC & Biot.

BWO CDC & Biot |
BWO CDC & Biot Materials |



Daiichi 1140 (#18 – 22), Alec Jackson Chironomid (15 or 17), or TMC 206 (#16 – 20)


Olive dun 8/0


Zelon – mayfly brown


Goose or turkey biot – BWO color


CDC feathers or puffs – dark dun or natural


Superfine dubbing – olive dun or BWO


  1. Attach thread to hook behind hook eye and wind backwards about halfway.
  2. Tie in Zelon and pull upwards to keep materials on top of hook while continuing to wrap thread just past hook bend.
  3. Tie in turkey biot by tip. Use thread to create slight taper ending at thorax.
  4. Coat hook with head cement or a super glue product to strengthen biot.
  5. Wrap biot forward to 1/3 behind hook eye.
  6. Select 2 CDC feathers or 1 puff and tie in with 2 loose wraps. Holding the CDC butt and tip, slide butts forward until wing length is even with bend of hook.
  7. Dub thorax. Be sure to add wraps behind CDC which makes the wing stand upright.

This is a variation of a Sparkle Dun – BWO.

Personal tying notes:

  • I’ve started using Daiichi 1140 hooks for this fly. A size 18 1140 equals a size 20 Tiemco. Read more in my Comparable Fly Fishing Hooks post.

Here is a link to my RiverKeeper Flies YouTube channel where I demonstrate tying how to tie the fly. 

Biots: Turkey vs. Goose

What’s the difference between turkey biot and goose biot? Turkey biots are longer and narrower, whereas goose biots that are shorter and wider. Here are two Blue Wing Olive biots. The longer and lighter colored biot is turkey.

Biots |

When working with goose or turkey biots, the way the biot is tied on will determine whether the body is smooth or has a furled rib. Here’s how.

Furled body – tie in the biot with the concave toward the hook. If you pull the biot off the stem rather than cutting it, there is a remaining notch pointing toward you.

Tukey Biot - Furled |

 This is what the final body looks like. 

Tukey Biot - Furled |

Smooth body – reverse how the biot is tied in. The convex side or natural curve will face up and the notch will face away from you. Not only will the body be smooth, there is a natural light/dark ribbing. 

TurkeyBiot - Smooth |

What’s the bottom line? There isn’t a right or wrong way. It just depends how you’d like the body to turn out. 

If you’d like more information on CDC, check out my post – Use Fly Patterns with CDC Feathers.

For more information on Blue Wing Olives, read the post – Blue Wing Olive Mayfly and Blue Wing Olives.


    1. Richard (or Dick?)

      Thanks for your comment. Never thought about “making” my own. They are so cheap at the fly shops, I’ve always selected the colors I wanted from them. Having said that, biots are from the leading edge of bird flight feathers. If you get a wing, look closely at the leading edge.


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