The Callibaetis Sprout is an emerger pattern, designed with a white foam wing case for excellent visibility. Apply floatant only to the hackle of the fly. The half submerged fly looks like a struggling callibaetis mayfly, attempting to hatch, and very vulnerable to trout!. This emerging dry fly closely resembles the natural mayfly emerger for tough to catch, selective trout. Use it when trout are gently sipping callibaetis from the surface of the lake.