Large Alderfly vs Japanese Dobsonfly
Side-by-side species comparison
| Attribute | Large Alderfly | Japanese Dobsonfly |
|---|---|---|
| Scientific Name | Sialis nigripes | Protohermes grandis |
| Order | Megaloptera | Megaloptera |
| Family | Sialidae | Corydalidae |
| Size | 15-20 mm | 40-60 mm body length |
| Habitat | Rivers & Streams | Rivers & Streams |
| Diet | Herbivores | Predators |
| Regions | North America | East Asia, Japan |
| Conservation | Least Concern | Least Concern |
Large Alderfly
A relatively large alderfly with dark wings and black legs found near rivers in eastern North America. Adults rest on streamside vegetation during the day.
Did You Know?
Alderfly larvae breathe through feathery gills along their abdomen and a single long tail filament that acts as an additional gill.
Japanese Dobsonfly
A large aquatic insect known as 'hebi-tonbo' (snake dragonfly) in Japanese. The adult males have elongated, curved mandibles. Larvae called 'magotaro-mushi' are used as fishing bait.
Did You Know?
Dobsonfly larvae are prized as live fishing bait in Japan and are collected from stream rocks by anglers targeting ayu (sweetfish).