The RS2 Emerger is a Mayfly imitation that is considered by many anglers to be one of the most effective emerger patterns. The RS2 can be tied in any color to match any species of emerging Mayfly. During a hatch, the emerger stage is the most vulnerable stage of an emerging Mayfly making them easy prey for hungry trout. The RS2 was first created more than 40 years ago by Rim Chung and for you trivia buffs the RS2 stands for Rim’s Semblance #2. Rim Chung is a Colorado fly tier and entomologist extraordinaire who developed the RS2 to fool some of Colorado’s picky tailwater trout that dine on tiny Blue Winged Olive Mayflies. It has since evolved into every serious dry fly anglers fly boxes.
Probably the best attribute the RS2 has is its ability to imitate all Mayflies when tied to the right size and color. There is no other emerger fly pattern that has caught more trout, during a hatch, year in and year out than Rim’s RS2. If you don’t have RS2 in your fly box you have just made a big mistake. The profile of the RS2 on the water is the real killer trigger. The body of the RS2 lies on or in the meniscus (surface film) giving the trout a clear underwater view of the its prey which will trigger it to strike. Great emerger patterns are always either in, on or just under the meniscus. The next trigger is the wing itself. There are many different styles of RS2 emerger patterns that have morphed onto the fly fishing scene the last 40 years and often the RS2 that you bought at one fly shop is different from the one you bought at another shop. It can be tied in different colors to imitate different mayflies and the wing can be made of hair, feather or CDC plums. It can have various tails and the wing can be either just a bump of material or a large sail. What is important to you is you buy or tie the right size and the right body color for the Mayfly you want to imitate.