Black Mayfly vs White Miller Mayfly

Side-by-side species comparison

Attribute Black Mayfly White Miller Mayfly
Scientific Name Ephemera danica var. nigra Ephoron virgo
Order Ephemeroptera Ephemeroptera
Family Ephemeridae Polymitarcyidae
Size 15-25 mm body 12-18 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
Regions Europe Europe, Western Asia
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.

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Did You Know?

The dark form predominates in acidic upland streams while the typical yellow form prefers alkaline lowland rivers.

White Miller Mayfly

A white-bodied European mayfly that emerges in enormous synchronized swarms at dusk. Females are unique among mayflies in that they moult directly into the spinner stage.

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Did You Know?

Swarms at bridges and streetlights can be so thick they cause traffic hazards.