Western Iron Dun vs Iron Blue Dun

Side-by-side species comparison

Attribute Western Iron Dun Iron Blue Dun
Scientific Name Epeorus longimanus Baetis muticus
Order Ephemeroptera Ephemeroptera
Family Heptageniidae Baetidae
Size 10-14 mm 5-7 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
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.

Iron Blue Dun

A small dark mayfly that hatches prolifically on cool overcast days. Nymphs are found clinging to stones in moderate to fast current.

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Did You Know?

Hatches are most prolific during rain and cold snaps, making it a favorite species for wet-weather anglers.