What actually happens in northern cabbage or cauliflower is a complex population of LEPIDOPTERA pests, mainly Pieris rapae. The common insect species are cabbage moth, Plutella xylostella, Spodoptera argentea, Pieris rapae, etc., but they usually account for a small proportion, and the occurrence time is similar to that of Pieris rapae. Except for Plutella xylostella, their drug resistance is generally not strong, and most of the pesticides currently used are broad-spectrum pesticides. Therefore, they can play a role in treating other LEPIDOPTERA pests while controlling Pieris rapae.