Tails and legs Silicone rubber legs (Life Flex style), black (two pairs)
Body and wing case Scud Back, black (one strip, as it comes)
Thorax UV Ice Dub, 50/50 purple and black (a pinch)
How to tie it
Mount a Saber 7230 in size 8 with a 3.5mm silver tungsten bead and exactly fifteen wraps of.015 lead pre-wound on the shank. Fifteen is not arbitrary. It is the length that leaves the abdomen and thorax in proportion with room for the wing case.
Start black UNI 6/0 and tie in the first tail on the far side of the hook, running the tie-in all the way forward to the lead so the body shape is maintained, then the second on the near side.
Hold the tails open with your fingers as you come back over them. That is what makes them splay out cleanly rather than collapsing along the shank.
Trim the tails to about the length of the body.
Tie in the black Scud Back right behind the lead. Josh uses it in the width and length it comes off the card, no trimming.
Palmer the Scud Back forward the same direction as your thread wraps. Overlapping it that way gives the segmentation, and the profile stays genuinely thin, which is the point of the fly and how it sinks fast on less weight.
Mix ice dub roughly fifty-fifty, UV purple with UV black.
Tie in the front legs before dubbing: one on the far side of the hook first, then take the long tag round to the near side so all four legs go in with one swoop. Efficiency is the theme of Josh's patterns. As little material as possible, tied fast.
Dub the mixed ice dub thorax up to behind the bead.
Pull the same Scud Back strip forward over the thorax as the wing case, stretch it tight, and smash it down with a few firm wraps.
Whip finish behind the bead.
Trim the front legs to about the same length as the tails - Josh likes them long, because that length is what gives them movement in the water. And pick the thorax out with a scrap of velcro.