BWOfly fishing glossary
Blue-Winged Olive — a common mayfly genus (Baetis) important in fly fishing.
Blue-Winged Olives (BWOs) are small mayflies in the genus Baetis that hatch prolifically on overcast, drizzly days. They're one of the most important hatches for trout across North America.
When They Hatch
BWOs have multiple generations per year, with peak activity in spring (March–May) and fall (September–November). Sizes range from #16 to #22.
Patterns to Match
- Parachute Adams (#18–20)
- RS2 Emerger
- Sparkle Dun
- Pheasant Tail Nymph