幼虫

1. Origins, structure, and basic meaning

• Structure: 幼虫 (ようちゅう) is a noun for an insect in its larval stage, rendered as larva or caterpillar by context.
• Basic usage: 幼虫を見つける names what was found, while 幼虫と成虫を見比べる sets the larva against the adult insect.

2. Common pitfalls and similar expressions

• Larval 幼虫 versus adult 成虫
  • The comparison with 成虫 identifies a life stage rather than a small adult; caterpillar is suitable only where that kind of larva is intended.