BWO Flies

Baetis
Perhaps the most reliable emerging insect in the world of fly fishing, the blue-winged-olive hatches in the spring and fall in the U.S. Rockies have turned many casual anglers into committed trout bums. Even when conditions are poor by typical standards, these insects love cold water, overcast conditions, and a bit of rain. BWO flies are typically small, with adults measuring around 1/4 inch in length, and are known for their distinctive grayish-blue coloration. BWO flies is an important food sources for trout, and their hatches can be prolific, occurring throughout the year in some areas.