May is Blue Winged Olive Time (BWO) and it’s the first may fly of the season and the real beginning to may fly emergence throughout the season. This early in the season trout often will take the adult BWO as easily as the emerger. When you come across rising fish really stop to study the rise forms the trout are making. Most often you can read the rise forms and make a good guess to which fly the rising fish are taking. It’s either the dry dun or the emerger. Most often anglers hedge their bets by offering both at the same time. If you are new to fly fishing it’s a good choice to present both and let the trout figure out which they prefer.