cabbageworm; caterpillar of the cabbage white butterfly
Specifically refers to the green caterpillar of the cabbage white butterfly (モンシロチョウ), often found on cabbage and related plants.
キャベツの葉に青虫がついていた。
There was a cabbageworm on the cabbage leaf.
青虫
The cabbageworm is the larva of the cabbage white butterfly.
Standard kanji spelling.
Kana spelling, common in children's books or when the kanji is not needed.
Compound of 青 (ao, 'green') and 虫 (mushi, 'insect/worm'), literally 'green worm'. The exact historical derivation is uncertain, but the word has long been used for the green caterpillar of the cabbage white butterfly.