Western Fishfly vs Common Alderfly

Side-by-side species comparison

Attribute Western Fishfly Common Alderfly
Scientific Name Neohermes filicornis Sialis lutaria
Order Megaloptera Megaloptera
Family Corydalidae Sialidae
Size 40-55 mm wingspan 12-16 mm
Habitat Rivers & Streams Ponds & Lakes
Diet Predators Predators
Regions Western North America Europe, Asia
Conservation Least Concern Least Concern

Western Fishfly

A western North American fishfly with feathery antennae and brownish wings. Adults are attracted to lights near streams where their larvae develop.

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Did You Know?

Fishflies are distinguished from dobsonflies by their feathery antennae and lack of massive mandibles in males.

Common Alderfly

A dark smoky-winged insect commonly found near still or slow-moving waters across Europe. Its aquatic larvae are predators in lake and pond sediments.

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Did You Know?

Alderfly females lay hundreds of eggs in neat rows on vegetation overhanging water, and the larvae drop into the water upon hatching.