Rock Bristletail vs Burrowing Mayfly

Side-by-side species comparison

Attribute Rock Bristletail Burrowing Mayfly
Scientific Name Petrobius brevistylis Hexagenia limbata
Order Archaeognatha Ephemeroptera
Family Machilidae Ephemeridae
Size 9-12 mm 18-32 mm body
Habitat Beaches & Coastal Ponds & Lakes
Diet Omnivores Omnivores
Regions Europe North America
Conservation Least Concern Least Concern

Rock Bristletail

A coastal bristletail found on rocky shores from Scandinavia to the Mediterranean. It has shorter cerci than the related P. maritimus.

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Did You Know?

It can tolerate brief immersion in seawater during high tides.

Burrowing Mayfly

Creates massive synchronized emergences so dense they appear on weather radar. Billions emerge simultaneously from lake bottoms where nymphs burrowed for up to two years.

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Did You Know?

Mayfly emergences along the Mississippi River are so massive they show up on Doppler weather radar — billions of insects rising simultaneously look like approaching thunderstorms.