Pale Morning Dun vs Japanese Burrowing Mayfly

Side-by-side species comparison

Attribute Pale Morning Dun Japanese Burrowing Mayfly
Scientific Name Ephemerella excrucians Ephemera japonica
Order Ephemeroptera Ephemeroptera
Family Ephemerellidae Ephemeridae
Size 7-10 mm 15-25 mm
Habitat Rivers & Streams Rivers & Streams
Diet Detritivores Omnivores
Regions North America Japan, East Asia
Conservation Least Concern Least Concern

Pale Morning Dun

A small pale yellowish mayfly that hatches in large numbers on western North American streams during late spring. It is a crucial food source for trout.

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Did You Know?

Pale morning duns often hatch in such dense swarms that trout become highly selective, ignoring all but perfect imitations.

Japanese Burrowing Mayfly

A large burrowing mayfly native to Japanese rivers and streams. It emerges in large numbers during early summer evenings.

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Did You Know?

It is culturally significant in Japan, where mayfly emergence has been celebrated in poetry for centuries.