North American Alderfly vs Smoky Alderfly

Side-by-side species comparison

Attribute North American Alderfly Smoky Alderfly
Scientific Name Sialis infumata Sialis fuliginosa
Order Megaloptera Megaloptera
Family Sialidae Sialidae
Size 15-20 mm wingspan 12-16 mm
Habitat Rivers & Streams Ponds & Lakes
Diet Predators Omnivores
Regions Eastern North America Europe
Conservation Least Concern Least Concern

North American Alderfly

A small, dark-winged alderfly common near ponds and slow streams across eastern North America. Adults are clumsy fliers often found resting on streamside plants.

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Did You Know?

Larvae spend one to two years burrowing in pond mud before emerging for a brief adult life of just days.

Smoky Alderfly

A European alderfly distinguished from S. lutaria by its preference for flowing water rather than still ponds. It has dark smoky wings and a blackish body.

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Did You Know?

This alderfly is a reliable indicator of clean running water and is one of the first species to disappear when streams become polluted.