dobsonfly; Protohermes grandis
Refers to a large aquatic insect of the Corydalidae family, especially the species Protohermes grandis found in Japan. The name literally means 'snake dragonfly' but it is not a dragonfly.
I found a dobsonfly near the river.
Dobsonfly larvae eat aquatic insects.
Katakana spelling is the most common written form for this insect name.
Kanji spelling is rare and mainly encountered in specialized contexts; the word is usually written in kana.
The name ヘビトンボ (蛇蜻蛉) literally combines 蛇 (へび, 'snake') and 蜻蛉 (とんぼ, 'dragonfly'), likely referring to the insect's long, snake-like appearance or its large mandibles. The exact origin is uncertain.