Yarn Wing Dun-Hendrickson
Of all the medium-sized mayfly designs that I’ve fished over the years, this one is the best. Its single wing causes the fly to slide aerodynamically through the air when cast. The poly yarn of the wing sparkles and twinkles like the wing of the natural while still allowing some light to pass through. The fan tail holds the imitation’s butt up, and the “X” style hackle–wound over the thorax and clipped on the bottom—suggests the positioning of the natural’s legs better than any other hackling style. Bending the front third of the hook up a bit causes the fly to plop down on its thorax, wing up every time.
First, the illustrations that Jason did for my book, Designing Trout Flies (1991). Anout 10 years after the publication of that book, I began bending the shank to position the fly more precisely in the film. I’ve shown the new look in the four photos that follow the illustrations.
I start the thread about in the mid point of the shank, wrap to the rear and form a lump of thread just onto the bend of the hook.
The tail fibers are tied in just ahead of the thread lump. The thread is wrapped back tight to the lump to fan the tail.
Dub on the abdomen, tie in a hackle feather, dub on the thorax.
Wind the hackle "X"-style.
"X" forward and rearward and use up the entire hackle feather. Only one feather is needed.
Comb the poly yarn before tying it in so that the fibers flare nicely. Finish the head in front of the wing butt.
Trim the wing butt the same length as the hook eye and trim the wing with one snip of the scissors.
Cut the hackle off the bottom of the fly.
Tail, abdomen, thorax in placed, hackle feather tied in. Note the bent hook shape.
"X" hackle in place.
Wing tied in.
The finished fly. It plops in with the thorax right down in the surface film, wing upright every time. Put a healthy drop of thin flexible head cement right where the wing is tied in. It will soak into the wing, the thread, and the wing butts and keep everything nicely in shape.