noun
spider mite
Refers to any mite of the family Tetranychidae, common agricultural pests. Usually written in katakana.
ハダニが野菜の葉に大発生した。
Spider mites have infested the vegetable leaves.
ハダニの駆除には専用の薬剤を使う。
Use a specialized pesticide to control spider mites.
The Japanese name ハダニ (葉壁蝨) literally means 'leaf tick/mite', from 葉 (leaf) and 壁蝨 (tick/mite). The exact derivation is uncertain, but it is a descriptive compound referring to its habitat and appearance.