Western Iron Dun vs Common Mayfly

Side-by-side species comparison

Attribute Western Iron Dun Common Mayfly
Scientific Name Epeorus longimanus Ephemera danica
Order Ephemeroptera Ephemeroptera
Family Heptageniidae Ephemeridae
Size 10-14 mm 15-25 mm body
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Detritivores
Regions North America Europe
Conservation Least Concern Least Concern

Western Iron Dun

An iconic eastern mayfly that signals the start of spring fly-fishing season. Nymphs have only two tails and cling to rocks in fast current.

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Did You Know?

It was named after Theodore Gordon, considered the father of American dry-fly fishing.

Common Mayfly

Adults have no functional mouths and live only 1-3 days. Massive synchronized emergences called "hatches" are among natures great spectacles. Excellent water quality indicators.

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Did You Know?

Mayflies have the shortest adult lifespan of any insect — some species live just 5 minutes as adults, long enough only to mate. They are the only insects with a winged sub-adult stage.