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Simplified split-case pale morning dun: Wired-in PMD

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Tying the Wired-in Split Case PMD: a way to tie a slimmer-profile, yet weighted, split-case pale-morning-dun (PMD) nymph. The backstory and tying instructions for this fly are posted at: youtu.be/XpLL6fBvPrA

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Scale of Photographs: the fly is about 8 mm long from the tip of the hook eye to the start of the hook bend. the tip of the chuck of the fly tying vice is about 5 mm across.

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A fish eye effect of the camera/lens system I used for the pictures above seems to distort the proportions of the fly and in particular makes thorax seem thicker and wider than it is on the slimmer version of the Wired-in PMD I normally tie for stream use.  So shown here are four of the Wired-in PMD flies on a USA Dime. For scale, the width of a dime is 17.9 mm. 

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This post, rather than about yet another split-case PMD design based on a pheasant tail (PT) nymph, is about tying a new look wing case, a wired-in wing case, to make a PT a split case nymph. This method can be used to convert most popular mayfly nymph patterns into a split-case design simply by tying in a thin piece of wire over the wing case.

This pattern uses Semperfli brand 30 denier Nano-Silk as the tying thread that is strong enough to be split apart with a dubbing needle to make dubbing twists. Dubbing twists are used in the wired-in design to: (1) form the thorax of the fly, and (2) make tightly bound spun dubbing fibers that are picked out from the thorax to form the legs of the fly.

The wired-in PMD uses an atypical weighting method where thin lead wire is lashed to the top of the hook under the area where the thorax will lie. Lashing the weight there helps keep the hook gap open which is important on the small hooks used for PMD patterns. The top weighting also promotes inversion of the hook point so that it tends to ride up in the water-- a position that helps avoid hookups on the stream bottom. Adding weighting to the fly design also helps the fly dangle down on the dropper tippet so that there is less slack in the tight-line system I use – enhancing strike detection.

Recipe

Hook: a 1x short or wide-gap scud/pupa hook, size 16-20 shank size to fit size of nymph screened out of target stream. Hook model used is barbless or the barb pinched down. The tie in the video uses a Tiemco 2487 size 18.

Thread: Semperfli brand Nano-Silk 30 denier thread, Copper or brown color to fit with local natural coloration.

Weight: 0.010 inch diameter lead wire or use a less toxic, but still thin, weighting wire. To prepare for lash in, lead wire is folded to make it run side by side and the wire tips cut-off to make them even. The run of lead wire is lashed in and folded over itself on top of the hook and lashed in again. This process is repeated as needed to build up the weight under the thorax, usually about two or three folds of lead. Complete thorax weighting by covering the lead with thread.

Tie in Ribbing: After completing the thorax, wind the thread towards rear of hook and along the way tie in a piece of small amber wire that will become the ribbing. After winding over the ribbing wire, the thread ends up at the hook bend ready to tie in the tail.

Tail: pheasant-tail-like colored guard hairs from an animal fur patch. Depending on the desired look, I use dyed brown squirrel tails, or translucent brown muskrat or beaver guard hairs. I use guard hairs because I find PT fibers break off too easily.

Abdomen: Two or three copper-brown colored PT fibers, the number used decreasing with the hook size. Other colors of PT may be applied here to fit the local natural coloration. See discussion of typical abdomen and thorax coloration in tying notes #2

Ribbing: Small amber copper wire spiraled tightly over abdomen to help stabilize the PT fibers there but at the same time loosely spiraled enough that the PT barbules are not lashed down.

Split case wire: After tying in abdomen, add a thin wire at the rear of the thorax area weight. Put a kink in the wire at the point of tie-in to keep it from pulling out. Cut-off tag end. Then tie in wing case Many wire color options for the split case wire, so as always, suit your taste or the naturals. Single strand of UTC Ultra-wire brand in small to BR size (wire diameter decreases with hook size) in the fluorescent yellow or fluorescent orange color, or, hot orange and hot yellow color. Also consider using a single strand of Sybai brand pale orange flat wire in small to medium size scaled to suit size of fly.

Wing case: Dark brown to near black-colored PT fibers to give the impression of the dark wing pads on a near-emergence PMD nymph.

Thorax: Ice dub, pheasant tail color, fibers thinly spread out crosswise and along a waxed and divided segment of the Nano-Silk thread and the thread then spun to make a tightly wound spiky yarn. The spun yarn is tied in using a figure-8 pattern over the thorax weight area and then tied off at the hook eye.

Finish: Fold over wing case PT fibers and tie in at eve. Cutoff end of the fibers at thread winds. Fold over split case wire and tie it in. Bend wire up at thread winds and cut off the wire close as possible to thread. Complete fly with a double whip finish but no head cement added.

 

Tying Notes:

1) Tungsten Bead variant: because some flyfishers (For example, see John Barr’s book “Barr Flies”) conclude that tailwater trout have become resistant to taking beaded flies, this fly is tied sans bead. That said, outside of fishing over these sensitized trout, I like to use a like a beaded fly and so a slotted tungsten bead 1.5 to 2 mm diameter can be added behind the hook eye at the start of the fly, before the leaded underlay of the thorax area is tied in, if still wanted. Yes, I often double weight these small flies to get them down quickly for tight-line fishing.

2) The wing case wire overlay color used as noted above in the split wing case section is varied but also the color scheme of the underlying mayfly nymph is changed to match the local natural nymphs. Jason Neuswanger at http://troutnut.com notes that PMD nymphs come in shades of very dark brown, a range of cinnamon colors as well as shades of olive – all within the same species but varying over a geographic range.

3) Variants using classic mayfly nymphs. Again most any mayfly nymph patterns can be converted to the split case look using wired-in wind case concept. For example: (1) an olive to dark olive Baetis nymph with a Silver-gray or light blue wire over a wing case made of dark PT fibers; or (2), a hares ear with a yellow or orange wire tied in over a wing case made of dark PT fibers.

4) The wing case wire, as well as the abdomen ribbing and use of ice dub as thorax dubbing adds an element of subtle flash to the fly design that I find to be an advantage when fishing over tailwater fish. Just a bit of flash to bring the fly alive and to the fishes attention seemingly without putting them off. Subtle flash elements on a fly seems to increase catch rates perhaps by allowing the fish to notice as well as distinguish the fly from the non-edible particulate debris moving through in the stream with the food items.

5) Testing the Wired-in PMD in the Deckers area of the South Platte River has proven the flies usefulness with picky trout. Note that to make the fly more visible in the photograph shown here the fly was tied extra larger than desirable for the tailwater trout. In fishing tailwaters, it pays to reduce the profile of the fly by using thin-shank hooks, limiting the weighting to two folds or no folds (unweighted), using fewest possible PT tail fibers for the wing case, a small size wire for the split case and reducing the number of figure-8 lashes covering the weighted area.

 

 

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I see you and I will get along REALLY WELL!  You see I type directions out so that there is little chance for confusion - also I like to talk a lot as well!

Nice tie and thanks!

Kim

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Weight: 0.10 inch diameter lead wire or use a less toxic, but still thin, weighting wire.

 

Shouldnt that be 0.010 not 0.10?

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2 hours ago, flytire said:

Weight: 0.10 inch diameter lead wire or use a less toxic, but still thin, weighting wire.

 

Shouldnt that be 0.010 not 0.10?

Good catch. I corrected the recipe. Thanks. 

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I have posted a video on the back story of this fly and how to tie it on YouTube.com: I have posted a video on the back story of this fly and how to tie it on YouTube: youtu.be/XpLL6fBvPrAXpLL6fBvPrA

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