Smoky Alderfly vs Japanese Alderfly

Side-by-side species comparison

Attribute Smoky Alderfly Japanese Alderfly
Scientific Name Sialis fuliginosa Sialis japonica
Order Megaloptera Megaloptera
Family Sialidae Sialidae
Size 12-16 mm 15-25 mm wingspan
Habitat Ponds & Lakes Rivers & Streams
Diet Omnivores Predators
Regions Europe Japan, East Asia
Conservation Least Concern Least Concern

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.

Japanese Alderfly

A medium-sized alderfly found in ponds and slow streams across Japan. It is one of the most common megalopterans in East Asian lowland waters.

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Did You Know?

It is one of the few megalopterans adapted to living in rice paddy fields.