When does the Pale Morning Dun hatch?

June–September, typically 10:00–14:00. It starts from about 11°C, peaks around 15°C and tails off by 20°C.

What flies imitate the Pale Morning Dun?

PMD Sparkle Dun, PMD Comparadun, Rusty Spinner, typically on a #16–14 hook.

How big is the Pale Morning Dun?

Spinner stage: 6–9mm. That matches a #16–14 hook.

Mayfly · Aquatic insect

Pale Morning Dun

Ephemerella excrucians

Size

6–9mm

Hook size

#16–14

Hatch window

Season June–SeptemberPeak time 10:00–14:00

Water temperature

15° peak

11°20°

How fish feed on it

A rusty-bodied fall, usually early morning or evening, and often heavier than anyone notices because it happens either side of when people fish. Flat water below a riffle, spent wings, quiet sipping rises.

Flies that imitate this

PMD Sparkle Dun

PMD Comparadun

Rusty Spinner

Ecology

Rivers & stillwaterTailwatersChalk streams

Where you'll find this

North America — WestPresent

Present throughout

Identification

Ephemerella excrucians , the pale morning dun , is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in all of Canada and the continental United States.

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