noun
beneficial insect; useful insect
Refers to insects that are helpful to humans, such as pollinators or natural pest controllers. Often contrasted with 害虫 (pest).
テントウムシはアブラムシを食べる益虫です。
Ladybugs are beneficial insects that eat aphids.
農家は益虫を増やすために農薬の使用を控えた。
The farmer reduced pesticide use to encourage beneficial insects.