菜青虫主要危害甘蓝、油菜、萝卜、白菜等。菜青虫是菜白蝶的幼虫，根据菜白蝶产卵有选择性，有趋向于甘蓝等含芥子油蔬菜类的习性，特别喜欢产在优良的结球甘蓝上。利用菜白蝶产卵的选择性，采用以下方法巧防：在种植十字花科蔬菜的菜圃里，种植一小块结球甘蓝，以诱集菜白蝶 Pieris main hazards cabbage, rape, radish, cabbage and so on. Pieris rapae is a larva of the genus Papilionidae. According to the selectivity of the cabbage butterfly spawning, there is a tendency toward the habit of mustard oil and vegetables such as cabbage, and is especially liked to be produced on the fine cabbage. The use of cabbage white spawn selectivity, the following methods cleverly defensive: Growing cruciferous vegetables in the vegetable garden, planting a small piece of cabbage, to attract the vegetable cabbage butterfly