Yellow May Dun vs Common Mayfly

Side-by-side species comparison

Attribute Yellow May Dun Common Mayfly
Scientific Name Heptagenia sulphurea Ephemera danica
Order Ephemeroptera Ephemeroptera
Family Heptageniidae Ephemeridae
Size 10-15 mm 15-25 mm body
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Detritivores
Regions Europe Europe
Conservation Least Concern Least Concern

Yellow May Dun

A bright sulfur-yellow mayfly common across European rivers during early summer. Its flat nymphs are adapted to fast-flowing water on stony substrates.

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Did You Know?

The striking yellow color of this mayfly makes it one of the most easily recognizable species on European rivers.

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.