BLUE WING OLIVE (BWO)

Description

The Blue Wing Olive (BWO) is one of the most important mayfly patterns in fly fishing, imitating the prolific Baetis species that trout feed on throughout the year. Known for their small size and olive-colored bodies with distinctive slate-blue wings, BWOs hatch during cool, cloudy days, often when other insects are scarce, making them a reliable food source for trout in rivers, streams, and spring creeks.

This pattern can be tied in various life stages—nymph, emerger, dun, and spinner—each offering unique opportunities to match trout behavior. The nymph version imitates Baetis crawling along streambeds, while emergers and cripples sit in the surface film, mimicking insects struggling to hatch. The dun variation floats high and is perfect during an active hatch, while spinner patterns represent adults returning to lay eggs.

The Blue Wing Olive is versatile, effective in both freestone and tailwater fisheries, and remains a staple fly for selective trout. Whether presented on a dead drift or in a dry-dropper rig, this fly is a must-have in every angler’s fly box for year-round success.