The Blue Winged Olive Dry Fly is the classic style tie of the important BWO, or Blue Winged Olive mayfly of the Genus Baetis and related mayflies. Hatches occur as early as February and gather momentum through June, take a slight break except for cloudy days during the summer, and then come back with a vengeance in late summer through November. In spite of all the new BWO patterns being originated, seemingly one a day, this classic tie in various sizes will take trout whenever the hatch is on strong. If the trout are being selective, try clipping the bottom of the hackle off, and presto, you have a low-riding Comparadun type of BWO.