poisonous insect
Refers to insects that are venomous or poisonous, such as certain caterpillars, bees, or centipedes.
この森には毒虫が多いので気をつけてください。
There are many poisonous insects in this forest, so please be careful.
Compound of 毒 (doku, 'poison') and 虫 (mushi, 'insect').