Yellow May Dun vs Black Mayfly
Side-by-side species comparison
| Attribute | Yellow May Dun | Black Mayfly |
|---|---|---|
| Scientific Name | Heptagenia sulphurea | Ephemera danica var. nigra |
| Order | Ephemeroptera | Ephemeroptera |
| Family | Heptageniidae | Ephemeridae |
| Size | 10-15 mm | 15-25 mm body |
| Habitat | Rivers & Streams | Rivers & Streams |
| Diet | Omnivores | Omnivores |
| 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.
Did You Know?
The striking yellow color of this mayfly makes it one of the most easily recognizable species on European rivers.
Black Mayfly
A dark color variant of the common Green Drake mayfly found in some European populations. The dark form is more prevalent in upland, acidic waters. Important for trout feeding.
Did You Know?
The dark form predominates in acidic upland streams while the typical yellow form prefers alkaline lowland rivers.