The original RS 2 was invented by Rim Chung in the early 1970's. His objective for designing the RS 2 was to come up with a simple, yet realistic nymph that imitated an emerging mayfly. Chung’s recipe included a straight-eye hook (Tiemco 101), split dark dun micro fibets, natural beaver fur, and the webbing off a gray saddle hackle feather (the fluffy material near the stem) for the emerging wing.
Many variations have spun-off the original pattern including: the Sparkle Wing RS 2, Mercury RS 2, Flashback RS 2, Foam Wing Emerger RS 2, and the Mercury Flashback RS 2. With no lack of respect toward Chung’s original pattern, these variations have improved the fly dramatically. Like their predecessor, they are effective under a wide range of conditions, especially, during the initial phases of a mayfly hatch.
The flashback RS 2 was invented by Roaring Fork and South Platte River guide Tom Whitley. His design incorporated a split, micro fibet tail (clipped), Adams Gray Super Fine dubbing for the abdomen, pearl Mylar tinsel for the back strap, and white ostrich herl for the wing. I tweaked his pattern and came up with my own variation—the Mercury Flashback RS 2. My pattern uses dark dun hackle fibers for the tail (for the ease of tying), gray Super Fine Dubbing for a thin and sparse abdomen, Glamour Madeira for the wing, and a small silver-lined glass bead to enhance the gas bubble-effect that occurs during the emerging process.