Biot Body Parachute Mayfly

I chose the biot body parachute mayfly as this month’s fly of the month for several reasons. First, by varying the colors used you can create a whole series of mayflies to cover the entire season of hatches. Second, I really like the biot body. It produces a smooth, waxy looking body that very closely represents the natural. And I prefer the parachute style – the body of the fly will sit right in the surface film, which I feel entices more strikes.  I would suggest tying this pattern in four or five basic colors – olive (as presented here), yellow, brown, cream and grey. Then tie some CDC biot body emergers (a pattern that is presented in another article on the site) to match the mayfly patterns. With these in your fly box, you’ll be ready for any hatch at any time of year, and the trout won’t stand a chance! So let’s get tying the


BIOT BODY PARACHUTE MAYFLY (blue winged olive version)


Hook: Dry Fly, size 12 - 18

Thread: Olive, 6/0

Tail: Dun Hackle Fibers

Wing Post: Poly Yarn

Body: Olive Biot

Thorax: Olive Dubbing

Hackle: Dun


  1. Start the thread on the hook behind the eye and create a thread base to the bend. Make 2 or 3 overlapping thread wraps at the bend to create a small ball of thread to help splay the tail. Tie in a tail of dun hackle fibers at the bend.
  2. Bring the thread about ¾ of the way back up the shank of the hook toward the eye. Tie in a wing post of poly yarn or similar posting material as follows:
    1. Place a length of poly yarn on top of the hook and tie it in place with several pinch wraps. The length of the bunch projecting out over the eye of the hook should be roughly equal to the length of the shank of the hook (to create a post that is roughly equal to the length of the shank.) Make sure the bunch stays on top of the hook by gently stroking the post up above the hook shank while tying in. Then trim and secure the butt ends (the butt ends in this case are the fibers that extend toward the bend of the hook.)
    2. Now establish and reinforce the post. Do this by pulling the fibers up so they extend above the shank at a 90 degree angle. Make some thread wraps directly in front of the post until it stays in this 90 degree orientation. Now bring your thread just in front of the post and make 4 or 5 horizontal wraps around the base of the post. You should make 4 or 5 wraps in touching turns up the post and then 4 or 5 wraps back down the post. Your wraps should go in a counter-clockwise direction.
    3. Wrap to the bend and select a turkey biot. If you examine the biot, you’ll notice it has 2 distinct sides. One is ridged, one looks like translucent cellophane. Tie the biot in by the tip on the near side of the hook with the cellophane side facing the rear of the hook. Now wrap the biot to create the body. Your turns should slightly overlap, with the cellophane edge overlapping and flattening the ridged edge. This will create a waxy smooth body that has a nicely segmented appearance. Tie off the biot just behind the post. Using hackle pliers to wrap the biot will be helpful.
    4. Prepare 2 hackle feathers by stripping off the fibers at the butt ends to expose some bare quill. Tie them in and wrap them as follows:
      1. Place the feathers together and hold them underneath the hook shank at a 45 degree angle to the hook, butts projecting toward the eye of the hook on the near side of the hook, tips projecting toward the bend on the far side of the hook, pretty sides up. Trap the quills with a few loose thread wraps to the bottom of the shank of the hook in front of the post. Now gently pull the feathers up along the post until the bare quill extends about 1/8 inch above the thread wraps you made to reinforce the post. Once positioned, secure the quills to the shank by wrapping toward the eye and back once or twice. Your thread should be hanging just in front of the post. Trim the butt ends.
      2. Now make 4 or 5 horizontal wraps up and down the post as you did when creating the post, securing the quill directly to the post and further reinforcing it.
      3. Dub a thorax. Apply dubbing to the thread and make a few wraps behind and a few wraps in front of the post to create a small ball of dubbing for the thorax.
      4. Now wrap the hackle. Wrap one feather in a counter clockwise direction in touching turns down the post. If you tied in the feathers correctly, you should have a small piece of exposed quill above the thread wraps. This exposed quill helps to maintain the horizontal alignment of the hackle when wrapping the hackle, helping the feather orient itself with respect to the post before the barbs begin to deploy. Use hackle pliers for this. Once you reach the dubbing (which will occur after 3 or 4 wraps of hackle), allow the feather to hang down below the shank on the far side of the hook. The weight of the hackle pliers will maintain the feather in the proper orientation. You can let go of the hackle pliers and then use your left hand to gently lift the hackle barbs out of the way while you tie the feather off. Tie it off in front of the dubbing ball. Wrap the second feather in the same fashion, wrapping through the fibers of the first feather. Tie it off in the same way.
      5. Using a whip finisher to apply the whip finish knot will help you slide your thread wraps under the parachute hackle. Carefully make your whip finish, trying not to trap the hackle barbs. Add a touch of cement and you’re ready to go!


This is a challenging fly to tie, definitely an intermediate level fly, but it is well worth the effort. Don’t hesitate to contact me with any questions you might have (, 610-730-7928.)