Blue Wing Olive (BWO) Dry Fly

The BWO dry fly imitates one of the most important and widespread mayflies in North American fly fishing — the blue-winged olive (Baetis). BWO hatches happen coast to coast on nearly every type of trout water, and they're one of the few hatches that occur reliably in cold, wet, overcast conditions when most other insects stay dormant. When the weather turns nasty, BWOs come off — and trout eat them eagerly.

This is a must-have pattern, period. If you fish trout, you will encounter BWO hatches, and having the right imitation in the right size is the difference between a great day and a frustrating one.

When to Fish It

Spring and fall primarily, but possible year-round in some waters. BWO hatches love overcast, drizzly days — the worse the weather looks, the better the hatch tends to be. Fish this fly drag-free to rising trout, targeting fish in softer water along current seams and in eddies where duns collect. Sizes 16-20 depending on the specific baetis species. Start with 18 if you're unsure.

Specs

• Type: Dry fly — Mayfly imitation (Blue-Winged Olive / Baetis)
• Hook: Light wire dry fly hook
• Style: Upright wing, natural olive body
• Best for: Trout — all water types during BWO hatches
• Technique: Dead-drift to rising fish, fine tippet presentations

Why Anglers Stock This Fly

BWOs are arguably the single most important mayfly for trout anglers. They hatch when other insects don't, they hatch everywhere, and trout love them. Not carrying BWO dries is like not carrying a Pheasant Tail — it's a gap in your box that will cost you fish. Sizes 16-20 cover the range. Hand-tied with quality materials by tiers with over 30 years of experience.

🎣 Cover the full BWO cycle? Add a Barr's Emerger and Silver Bullet Baetis for subsurface coverage.