Blue-Winged Olive

This is one of the most prolific genera of mayflies in North American trout streams. Their small size permits the growth of up to three generations per year, and they are good dry-fly insects because they often hatch in impressive numbers and the duns ride the water for a long time before taking flight.Some Baetis species are often the first major hatches in the spring and the last in the fall, and on especially stable spring creeks they may emerge throughout the winter. The genus is common nationwide.