You can make these things waaaaayyyy simpler than the stock pattern. Just a tail of whatever game bird feather (partridge, etc.), body of spandex wrapped under tension, slender wing case of either yellow holo tinsel or yellow poly, and buggy thorax of dark dubbing that will "pooch" up some when you pull the wingcase tight. So really a "skinny case" instead of a split case, with the thorax bulk taking some of the place of the biots. Also effective in purple...
Owner, Yellowstone Country Fly Fishing
Head Guide, Parks' Fly Shop
Fly Designer, Montana Fly Company
Author, Yellowstone Country Flies and River Characters