Control methods of Pieris rapae

(agricultural get Rich Network) first, chemical control. Rape should pay attention to check the insect situation after emergence, about one week after the peak of spawning, and the larvae should be applied before the third instar. Second, biological control. Using borer killing bacillus or green worm powder (containing more than 10 billion live spores per gram), diluting 2000 to 3000 times, and adding adhesives such as soap powder or tea withered powder according to 0.1%, the biological control effect is late, and the use period should be several days earlier than the chemical control. Third, protect natural enemies. Chemical pesticides with broad spectrum and long residual period are rarely used in the occurrence period of natural enemies. Artificial release of pink butterfly golden wasp, velvet star wasp and other parasitic wasps.