Western Firefly vs Small Square-Gilled Mayfly

Side-by-side species comparison

Attribute Western Firefly Small Square-Gilled Mayfly
Scientific Name Microphotus angustus Caenis luctuosa
Order Coleoptera Ephemeroptera
Family Lampyridae Caenidae
Size 8-12 mm 3-6 mm
Habitat Deserts & Drylands Ponds & Lakes
Diet Omnivores Omnivores
Regions North America Europe
Conservation Data Deficient Least Concern

Western Firefly

A rare western North American firefly with larviform females that glow. Males are winged but produce no light.

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Did You Know?

It is one of very few firefly species found west of the Rocky Mountains, where most people believe fireflies do not exist.

Small Square-Gilled Mayfly

A minute mayfly with distinctive square-shaped gills on its nymphs. Adults swarm in enormous numbers near water at twilight.

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Did You Know?

The enlarged second gill plate acts as a protective cover over the remaining delicate gills.