Black Mayfly vs Cold-water Glacier Midge

Side-by-side species comparison

Attribute Black Mayfly Cold-water Glacier Midge
Scientific Name Ephemera danica var. nigra Diamesa cinerella
Order Ephemeroptera Diptera
Family Ephemeridae Chironomidae
Size 15-25 mm body 3-4 mm body length
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Detritivores
Regions Europe Europe, Alps, Scandinavia
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.

Cold-water Glacier Midge

A cold-adapted midge found in high-altitude streams fed by snowmelt. Its larvae are among the first colonizers of newly formed glacial streams.

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Did You Know?

Adults can emerge and fly at temperatures just above freezing.