Thread White (abdomen), Black (thorax) 14/0 and 8/0
Materials
Tag Silver holographic tinsel (small, short tag at the bend)
Abdomen Micro-tubing over white thread (tan, olive, or chartreuse)
Legs Hungarian partridge fibers (6-8 fibers)
Head Natural gray ostrich herl (2-3 wraps)
How to tie it
Start the white 14/0 thread behind the eye and wrap a smooth layer back to just past the bend, about a quarter shank length down the curve.
Tie in a short tag of small silver holographic tinsel at the rearmost point. This flash imitates the gas bubble a caddis pupa carries as it rises.
Tie in the micro-tubing at the tag and build a smooth, level underbody of white thread forward to the 75% mark; the white base keeps the translucent tubing bright.
Wrap the micro-tubing forward in touching turns to the 75% mark, keeping each turn snug against the last so the abdomen stays segmented and glossy, then tie off and switch to black 8/0 thread.
Select 6-8 Hungarian partridge fibers and tie them in as a beard under the hook, tips reaching back to about the hook point, to suggest the trailing legs of the swimming pupa.
Tie in 2-3 strands of gray ostrich herl, take 2-3 turns to form a fuzzy head, tie off, and whip finish behind the eye.