Pieris rapae, alias White Butterfly and White Butterfly, its larvae are generally called Pieris rapae, which is a national pest. The insect likes to eat cruciferous plants, so cabbage, rape and Chinese cabbage suffer the most.

Control methods: ① Chemical control. The best period of chemical control is before the third instar of larvae. Pesticide killing is the first choice to control Pieris rapae, and it can also treat aphids. The key is to choose pesticides with high efficiency, low toxicity and low residue. You can choose one of the following chemicals for meticulous and thoughtful spray control, 90% trichlorfon or 5% Baishedu or 48% Lexben 1000 times solution and 45% Green Pepsi1000 ~1500 times solution, and the effect of alternate use of drugs is better. ② Combined with accumulated fertilizer. Concentrate the dead leaves, residual plants and weeds in the field to fertilize or burn them, and eliminate the hidden larvae and pupae. ③ Larvae and pupae can be killed artificially in the field, and adults can be caught by net before spawning.