Mayfly Emerger. The Mayfly Emerger can be used to imitate larger Mayflies like green and brown drakes, it can also be used on lakes and ponds to imitate smaller sized mayflies during their hatches. This fly has been popularly used on lakes in Algonquin and Southern Ontario. The Mayfly Emerger can be fished with a typical dry fly technique, ensuring that it has a drag free drift for the duration the fly is on the water.