leaf beetle (subfamily Donaciinae)
Refers specifically to beetles of the subfamily Donaciinae, often found near water.
The leaf beetle (Donaciinae) eats the roots of waterside plants.
Donacia provostii (species of leaf beetle)
Katakana spelling is common for this insect name.
Kanji spelling is rare; the word is usually written in kana.
The name is composed of 根 (root), 喰い (eating), and 葉虫 (leaf beetle), literally 'root-eating leaf beetle'. The exact derivation is uncertain, but it likely describes the larval feeding habit.