DescriptionMercer's Epoxyback Callibaetis Emerger is a shop favorite callibaetis pattern that we will be using on the High Lakes from now until the end of Summer. The Epoxyback is best fished either wind-drifted or slowly retrieved with an intermediate sinking line. This fly can also be used as dropper, fished underneath a callibaetis dry when the fish are keyed on the surface.