Wingcase Mottled Medallion sheeting or turkey (1 slip)
How to tie it
Optionally slide a small gold bead to the eye, then start the thread and tie in a short speckled tail at the bend to suggest the swimming mayfly's tails.
Tie in the rib, then build a slim tapered olive-brown abdomen (D-Rib or dubbing) to the 60% mark and counter-rib it for segmentation.
Tie in the wingcase slip pointing back over the abdomen.
Dub a fuller thorax mixing CDC fibers and UV Ice Dub so the loose CDC breathes like gills. Why: Callibaetis nymphs are active swimmers, and the mobile CDC fibers add lifelike gill movement.
Pull the wingcase forward over the thorax, tie down behind the eye, and whip finish.