Hot spot (optional) Fluorescent orange thread collar (trace)
How to tie it
Start the thread (slide on a tungsten bead first for the jig version) and tie in the silver rib at the bend.
Dub a fat, buggy rainbow sow-scud body forward, leaving room at the front.
Counter-wrap the wire rib forward for segmentation and durability, and pick out the dubbing to suggest legs and a fuzzy sowbug outline.
Tie in a CDC feather by the tip and take one or two turns as a soft-hackle collar, then sweep the fibers back. Why: CDC out-fishes partridge or hen here because the finer fibers pulse with even the slightest current.
Build a small (optionally hot-orange) thread collar and whip finish.