Black Mayfly vs Blue-Winged Olive
Side-by-side species comparison
| Attribute | Black Mayfly | Blue-Winged Olive |
|---|---|---|
| Scientific Name | Ephemera danica var. nigra | Baetis tricaudatus |
| Order | Ephemeroptera | Ephemeroptera |
| Family | Ephemeridae | Baetidae |
| Size | 15-25 mm body | 5-9 mm |
| Habitat | Rivers & Streams | Rivers & Streams |
| Diet | Omnivores | Omnivores |
| Regions | Europe | North America |
| Conservation | Least Concern | Least Concern |
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.
Blue-Winged Olive
A small olive-colored mayfly with distinctive bluish-gray wings, abundant in clean streams across North America. It produces multiple generations per year.
Did You Know?
Blue-winged olives are among the few mayflies that hatch in winter, providing vital food for trout during cold months.