When does the Eastern Blue-Winged Olive hatch?

March–November, typically 12:00–16:00 (overcast/drizzle best). It starts from about 6°C, peaks around 11°C and tails off by 16°C.

What flies imitate the Eastern Blue-Winged Olive?

BWO Sparkle Dun, RS2, WD-40, Blue-Winged Olive Parachute, typically on a #18–16 hook.

How big is the Eastern Blue-Winged Olive?

Spinner stage: 5–7mm. That matches a #18–16 hook.

Mayfly · Aquatic insect

Eastern Blue-Winged Olive

Baetis intercalaris

Size

5–7mm

Hook size

#18–16

Hatch window

Season March–NovemberPeak time 12:00–16:00 (overcast/drizzle best)

Water temperature

11° peak

6°16°

How fish feed on it

By the time the spinners are down the fly has finished its job and is simply lying there, spent, wings flat in the film, going nowhere. Trout know the difference between something alive and something that's stopped trying, and they take spinners with a quiet, unbothered sip that's easy to miss if you're still watching for something splashier. Look for them on the glides and in the slack water, wherever the current gathers what's left.

Flies that imitate this

BWO Sparkle Dun

RS2

WD-40

Blue-Winged Olive Parachute

Ecology

Rivers & stillwaterTailwatersChalk streamsTolerates poor water

Where you'll find this

North America — EastPresent

Present throughout

Identification

Baetis intercalaris is a species of small minnow mayfly in the family Baetidae. It is found in the south half of Canada and the continental United States.

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