Bead Head Barr's Emerger- John Barr created this bead head fly after a frustrating day on Nelson's Spring Creek. That night in his room, the Barr Emerger was born and with it one of the most productive mayfly emerger patterns on the market. This bead head fly is often used as the bottom fly on his famous Hopper, Copper, Dropper three fly rig. Color: Blue Wing Olive. Sizes: 18, 20, 22.