North American Backswimmer vs Japanese Dobsonfly

Side-by-side species comparison

Attribute North American Backswimmer Japanese Dobsonfly
Scientific Name Notonecta undulata Protohermes grandis
Order Hemiptera Megaloptera
Family Notonectidae Corydalidae
Size 10-14 mm 40-60 mm body length
Habitat Ponds & Lakes Rivers & Streams
Diet Predators Predators
Regions North America East Asia, Japan
Conservation Least Concern Least Concern

North American Backswimmer

A common backswimmer across North America that hunts by floating upside down at the surface. Its large eyes help it spot prey from below.

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Did You Know?

It is an important natural predator of mosquito larvae and can significantly reduce mosquito populations in small ponds.

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.

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Did You Know?

Dobsonfly larvae are prized as live fishing bait in Japan and are collected from stream rocks by anglers targeting ayu (sweetfish).