Olive Drake Mayfly vs Fatal Metalmark

Side-by-side species comparison

Attribute Olive Drake Mayfly Fatal Metalmark
Scientific Name Ephemera lineata Calephelis nemesis
Order Ephemeroptera Lepidoptera
Family Ephemeridae Riodinidae
Size 15-22 mm 18-25 mm wingspan
Habitat Rivers & Streams Rivers & Streams
Diet Detritivores Nectar Feeders
Regions North America Southwestern United States, Mexico
Conservation Least Concern Least Concern

Olive Drake Mayfly

A large burrowing mayfly with distinctive mottled brown wings. Nymphs excavate U-shaped burrows in sandy stream bottoms.

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Did You Know?

Mass emergences at dusk can be so dense they appear on weather radar.

Fatal Metalmark

A tiny dark brown butterfly with fine metallic silver lines across the wings and minute checkered fringes. Despite its ominous name, it is a harmless nectar feeder.

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Did You Know?

The name 'nemesis' refers to the Greek goddess of retribution, though the reason for this dramatic name is unclear.