Pests are insects or small animals which damage crops or food supplies.
例句
...crops which are resistant to some of the major insect pests and diseases...对一些主要病虫害有抵御能力的作物Each year ten percent of the crop is lost to a pest called corn rootworm.一种叫玉米根虫的害虫每年会让粮食减产10%。
N-COUNT
讨厌鬼（尤指儿童）
You can describe someone, especially a child, as a pest if they keep bothering you.
例句
He climbed on the table, pulled my hair, and was generally a pest.他爬桌子，拽我的头发，总之是个讨厌鬼。