My PTA has become a proven killer over the past several years. I believe a good portion of this flies’ success is attributable to its differentiation from other patterns. We all know that fish like contrast in a pattern, thus the success of two-tone flies like Copper Johns and many of Mike Mercer’s patterns. The PTA has a strikingly contrasted abdomen and thorax that provide the “hatching insect” trigger to the trout.
The twisted thread abdomen creates a durable ribbed effect while retaining the slimness of the natural. The wire thorax is also incredibly durable but also provides weight to the fly. I find this pattern often fishes like a bead head pattern but out produces beaded flies on waters where the fish have become bead shy. The two-tone effect matches that of a variety of mayflies, from PMDs to Baetis and even Callibaetis! This is a go-to fly for many and is sure to become a hot fly for you as well.
Hook: TMC 100SP-BL #14-20
Thread: UNI 8/0 Rusty Brown
Tail: Moose Hock
Abdomen: Gudebrod 00 Rod Winding Thread, Chestnut Brown
Wingcase: Lagartun Mini Flat Braid, Olive
Thorax: Black Ultra-Wire, small
Legs: Hungarian Partridge Body Feather
Coating: Sally Hansen’s Hard As Nails Clear Nail Polish
Attach the thread and build a smooth base back to the bend. Even the tips of three moose body hairs in your fingertips and tie them in at the bend. The tails should be one shank length long. Return the thread to the seventy percent point on the shank and clip the remaining butt ends off flush. Press your thumb nail up against the base of the tails to flare them out slightly as shown.
Put the Gudebrod rod thread in a bobbin with a non-flared tip. Leave a short tag of thread hanging from the tip of the bobbin. Lay the bobbin tube next to the shank and make a single turn of thread over the tube, tying it to the shank as shown.
Pull down on the tying thread and at the same time, withdraw the Gudebrod bobbin by pulling it to the rear of the hook. The tying thread will jump off the end of the bobbin tube and catch the tag end of the rod thread against the hook.
Wrap the tying thread back over the rod thread to the bend of the hook/base of the tail. Build a smooth, slightly tapered underbody with the tying thread as shown. The underbody should extend to the seventy percent point.
Let the Gudebrod bobbin hang below the hook and spin it to twist the rod thread into a cord. Be sure to spin the bobbin in the same direction as the thread twists to assure that you don’t unwind it first. Wrap the rod thread forward from the bend to the seventy percent point in tight, concentric turns. Tie off the rod thread at the end of the underbody (70% point) and clip the excess.
Tie in a piece of Mini Flat Braid at the front of the abdomen and wrap back over it to the fifty percent point. Be sure to keep the wraps smooth as you do this.
Continue building a slightly tapered under-thorax with the tying thread as shown. Be sure to leave an eye length worth of bare space between the front edge of the abdomen and the hook eye. End with the thread hanging at the front of the thread thorax.
Tie in a six-inch length of small black wire at the front of the abdomen. Wrap back over the wire, keeping it along the side of the thorax, back to the base of the wingcase. Return the thread to the front of the thorax.
Wrap the wire forward over the thread forming the thorax. Be sure to keep these wraps butted up against one another. Tie the wire off at the front of the thorax and helicopter the end of the wire until it breaks off.
Select a Hungarian partridge feather that has a relatively square tip. Clip the center quill (only) from the feather at a point that leaves the remaining fibers equal to the length of the hook shank. It helps to have a very fine tipped pair of scissors when clipping the stem. You want to only clip the stem and leave all the other fibers attached as shown. The cut should form a prominent “V” as shown.
Place the partridge feather on top of the hook at the front of the thorax with the outside of the feather facing up. The legs of the “V” should be on either side of the hook shank and the tips should extend just past the back end of the thorax. Get the feather in place and pinch it along the top of the hook to hold it there.
While holding the partridge feather in place, make a couple turns of thread (pinch wraps) over the base of the feather and tighten them slowly. This should splay the fibers along the sides of the fly and, if you’re lucky, slightly around the bottom of the fly as well.
Clip the butt end of the partridge feather flush against the hook shank and make a few more turns of thread to cover the butt ends.
Pull the Mini Flat Braid over the top of the thorax forming the wingcase. Tie the braid down at the rear edge of the index point.
Clip the remaining braid off at the index point and build a smooth clean thread head to cover the butts. Whip finish the thread.
Apply a thin coat of Sally Hansen’s Hard As Nails to the wingcase and thread head. I usually apply one thin coat to start and let it dry for about five minutes, then come back and apply another slightly heavier coat on top of that. The Hard As Nails shrinks down when it dries so it takes a couple coats to really build anything up.
Top View, finished fly. Note the length and splay of the tails, the length and proportion of the abdomen and thorax and the length of the legs.