Japanese Dobsonfly vs Cottonwood Borer

Side-by-side species comparison

Attribute Japanese Dobsonfly Cottonwood Borer
Scientific Name Protohermes grandis Plectrodera scalator
Order Megaloptera Coleoptera
Family Corydalidae Cerambycidae
Size 40-60 mm body length 25-40 mm
Habitat Rivers & Streams Rivers & Streams
Diet Predators Root Feeders
Regions East Asia, Japan Central and eastern United States
Conservation Least Concern Least Concern

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).

Cottonwood Borer

A large longhorn beetle with bold black and white patterning and long antennae. Its larvae bore into the roots and lower trunks of cottonwood and willow trees.

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Did You Know?

When handled, it produces a loud squeaking sound by rubbing parts of its thorax together.