The BWO dry fly - or, unabridged - Blue Winged Olive is a rather old pattern, and the corresponding flies can be found in many fisheries. It is not surprising that the corresponding imitation can be found in many fly boxes. Moreover, there are many different ways to tie this pattern. I´d like to present a rather simple way to tie a BWO with a CDC wing. To stabilize the way this pattern floats, the tails should be slightly longer than usual. Further information is to follow step by step.
As hook for fly tying this pattern I have chosen a Kamasan B405 in sizes 10 - 18. The size 18 flies are fished in late fall for grayling.
1. You start out by wrapping your flytying thread from the eye just a bit farther than halfway down the hook shank and then wrap it back towards the eye about halfways.
2. That is where you tie in your wing material, in this case a little bunch of CDC-fibers from suitable CDC-hackle feathers. The fibers should have a slightly blueish hue (blue winged!). Handling the CDC-fibers and feathers is easy; other than cock hackles, they can be clipped to the desired length without any problem.
3. Next you finish your basic wrap towards the bend of the hook. The protruding rear ends of the CDC-fibers are clipped at an angle and neatly covered by your basic wrap which you continue all the way down to the beginning of the bend.
4. Here´s where you tie in your tails. You may use a lot of different fibers, natural or synthetic. I use fibers from a cosmetic brush sold by ALDI, which yields over 100 tails for a few € ($). N.B.: whichever material you chose for a dry fly, it better be water repellent!
5. After clipping the butts of your tail fibers pointing towards the wing, you tie in both your ribbing material and your body thread at the hook´s bend.
6. Your main fly tying thread - here Dyneemathread 12/0 - is wrapped all the way to the wing (if you use a rotary vise like e.g. Norvise: all the way to the hook eye). If your body looks uneven, this is the time to fix that.
7.Now you form a nice even body with your body thread ( or dubbing ) and tie it down with your fly tying thread at the wing.
8. Next, make a nice rib with your ribbing thread, starting with relatively narrow ribs and getting wider towards the thorax. Take care to keep good tension on your thread. On nymph bodies, head cement or superglue may be used to stabilize your rib, never on dry fly bodies, though!
9. To imitate a few legs in the thorax area, tie in a cock hackle immediately behind the wing. For this hackle, color is much less important than size! in the photograph I have used a brown hackle.
10. Now make one to three wraps with your hackle (depending on available space)...
11. ...and wrap some more turns of the same hackle in front of your wing. Take care not to catch any of your wing fibers! The wing fibers should be long enough so you can hold them slightly back and upward with two fingers while making about three wraps with your hackle. As CDC fibers are very soft, the wraps of the brown hackle suffice to support the wing and hold it in place.
12. Finally, apply a whip finish and clip the CDC-wing to proper size. Your fly is finished.