How to control the cabbage white butterfly? These methods are simple and effective

(Agricultural Wealth Network) 1. Chemical control. After the rapeseed emerges, attention should be paid to inspecting the pest situation, and pesticide should be applied about 1 week after the peak of egg laying, before the larvae reach the 3rd instar. 2. Biological control. Use Bacillus thuringiensis or Bacillus moritai powder (containing more than 10 billion viable spores per gram), dilute 2000 to 3000 times, and add 0.1% of the pesticide amount of soap powder or tea seed cake powder and other adhesives. Biological control takes effect slowly, so the application period should be several days earlier than chemical control. 3. Protect natural enemies. During the period when natural enemies occur, use fewer broad-spectrum chemical pesticides with long residual effects. Artificially release parasitic wasps such as Pteromalus puparum and Trichogramma.