The Olive Dun Micro Mayfly is probably the most effective fly for Autumn time. In this time of the year grayling and trout pick small and delicate olives because they hatch in large number. The olives are the main food in cold period of the year and for this reason imitation of this fly are so effective. The CDC version is probably the best imitation of the natural insect and is highly effective on all kind of waters. We highly recommend it to be used even on educated and picky fish.
