Body Red thread or Flexi Floss (slim, deep in bend)
Rib Silver wire (spiral)
Coat UV resin (thin)
How to tie it
Mount the curved pupa hook and start red thread behind the eye.
Wrap the thread back well around the bend, further than feels right — the body needs to follow the curve of the hook to read as a worm.
Build a slim body forward with touching turns of red thread, or tie in a strand of Flexi Floss at the rear and wrap that forward. Two thin layers, no lumps: this fly is thin on purpose.
Catch in fine silver wire at the rear and spiral it forward in 5-6 evenly spaced turns for segmentation, then helicopter off the excess.
Stop one eye-length behind the eye and whip finish.
Coat the body with a thin layer of UV resin and cure. Keep it thin — a heavy coat rounds out the segmentation you just built.