Togens tungsten bead, matte black Black bead (3/32")
Lead wire (0.010", most of shank)
Hackle fibres (spade hackle) Black mayfly tail fibers (small pinch)
Semperfli brassie wire, 0.2mm Black wire (1 length)
Krystal Dub Black dubbing (body and thorax)
Stonefly scud back, 1/8" Black floss (1 strip)
How to tie it
Slide the 3/32" matte black bead onto the hook and seat it at the eye. Wrap 0.010 lead wire down nearly the full shank, then back over itself at the front to build a taper, and level it off with thread - Brent wants this fly as heavy as possible.
Tie in a short, sparse pinch of black hackle fibres at the bend. Early black stones have very short tails. Flatten the butts in behind the lead with smooth pliers.
Tie in the 0.2mm black wire at the rear.
Dub a thin body of black Krystal Dub over the rear half of the shank, keeping it slender. This is really an underbody, so trim any wild fibres.
Rib the body forward with nearly touching turns of the black wire and tie off, cutting the wire in the back corner of your scissors.
Tie in the 1/8" black stonefly scud back at the front of the body for the wing case, handle it gently. It stretches a long way.
Dub the thorax with more black Krystal Dub, slightly fuller than the body.
Pull the scud back over the thorax to the eye with light, even tension, tie it down, then fold it back over itself and secure. Do not overstretch or it will pull out.
Whip finish behind the bead. Pick out the thorax fibres to the sides with a fine dubbing picker for legs, trimming underneath so the legs come off the sides only.