Morris May Emerger - Callibaetis is a fly pattern engineered to imitate the standard mayfly of trout lakes, the Callibaetis. This emergent pattern targets late spring and summer hatches, with a repeat emergence possible in late summer to fall. On overcast days, the emerger attracts attention as trout swirl over hatching insects above submerged weed beds. It imitates Callibaetis mayfly emergers, the primary lake pattern for this hatch. Timed for late spring through summer, with a repeat emergence into fall, it delivers a natural presentation over weed beds where trout feed on emergers. The simple profile tracks true on the water, offering consistent presentation during hatch activity. Designed for trout lakes where Callibaetis emerge, this pattern gives anglers an effective tool to match the hatch across the late spring, summer, and fall windows. Features - Imitates Callibaetis mayfly emergers - Effective over submerged weed beds - Simple profile that tracks naturally over water - Timed for late spring through summer with fall emergence - Designed for consistent presentation in trout lakes