Solitude Mayfly Nymph Callibaetis (RN115) 6-PackCallibaetis are a must-have for most anglers. These mayflies are prolific in many of the Western Hemisphere's stillwaters including lakes, ponds and slow moving streams. In lakes that are heavily alkaline, these insects can hatch and resemble clouds of smoke. Trout, bass and panfish feast on Callibaetis Mayflies in the nymph, dun and spinner stages. Callibaetis nymphs reside in the weeds on the bottom of still and slow-moving water. Anglers can simulate the nymphs exiting the weeds, swimming up and back to the weeds. The Extended Callibaetis displays an up-sweeping abdomen to keep the tail up and above the water so it mimics the natural CallibaetisNymphs are excellent swimmers and usually swim to the surface following a shallow angle or almost straight. They speed through the water in 3 to 4-inch spurts. A slow retrieve with pauses can imitate the nymphs falling motion as they tire quickly.