The Mercury Flashback Pheasant Tail is a variation of Frank Sawyer’s original. The Mercury Flashback Pheasant Tail imitates a wide array of mayfly nymphs including blue-winged olives, pale morning duns, Tricos, and red quills. The extra flash not only helps the fly stand out, but it also simulates the flash created by all the tiny bubbles of air on the outer layer of the mayfly nymph’s exoskeleton when it hatches. Adding a glass bead also helps impart this illusion. The key to a good Mercury Flashback Pheasant Tail is tying it thin and sparse. I recommend using four-five pheasant fibers to create the entire fly (tail, abdomen, wing case, and legs).