noun
aquatic insect
Refers to insects that live in or on water for all or part of their life cycle, such as water striders, diving beetles, and dragonfly larvae.
池で水生昆虫を観察した。
I observed aquatic insects in the pond.
Compound of 水生 (suisei, 'aquatic') and 昆虫 (konchū, 'insect').