Black Mayfly vs Yellow-legged Dance Fly

Side-by-side species comparison

Attribute Black Mayfly Yellow-legged Dance Fly
Scientific Name Ephemera danica var. nigra Empis livida
Order Ephemeroptera Diptera
Family Ephemeridae Empididae
Size 15-25 mm body 7-10 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Nectar Feeders
Regions Europe Europe
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.

Yellow-legged Dance Fly

A medium-sized dance fly with yellowish legs, a grayish body, and a distinctive long proboscis. It forms conspicuous mating swarms near streams and in sheltered clearings.

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Did You Know?

In some dance fly species, males wrap worthless objects in silk to trick females into mating, a form of sexual deception.