Hook Standard dry fly hook (TMC 2488 or 101), 18-24
Thread Black (male) or pale olive (female) 14/0
Materials
Tail White Mayfly Tails / Microfibbetts (2-3)
Body Tying thread or black Superfine dubbing (wrapped)
Wings White poly/Sparkle poly yarn, spent (1 clump)
Thorax Black Superfine dubbing (pinch)
Hackle (optional) Badger rooster saddle (1)
How to tie it
Start thread and tie in 2-3 white Microfibbetts as a widely split tail slightly longer than the shank.
Wrap a slim thread abdomen (or lightly dubbed black body) forward to the 65% mark, keeping the male body black and slim.
Tie in a clump of white poly yarn across the shank and figure-eight it into two spent wings lying flat to the sides; use poly (not Antron) because it floats, and do not tie the wings too short, since real spinner wings look oversized to the body.
Dub a small black thorax around the wing base to suggest the head and thorax.
Optionally wind a turn or two of badger hackle and clip the top and bottom flush so the fly lies flat in the film. Whip finish and cement.
Grease the wings and thorax with floatant so the tiny fly keeps riding in the surface.