Rotation of insecticide classes is recommended, and the use of B. thuringiensis is considered especially important because it favors survival of parasitoids. Even B. thuringiensis products should be rotated, and current recommendations generally suggest alternating the kurstaki and aizawa strains because resistance to these microbial insecticides occurs in some locations. Mixtures of chemical insecticides, or chemicals and microbials, are often recommended for diamondback moth control. This is due partly to the widespread occurrence of resistance, but also because pest complexes often plague crucifer crops, and the insects vary in susceptibility to individual insecticides. Best results were obtained with daily evening applications.
Crop diversity can influence abundance of diamondback moth.
Larvae generally are fewer in number, and more heavily parasitized, when crucifer crops are interplanted with another crop or when weeds are present. This does not necessarily lead to reduction in damage, however. Surrounding cabbage crops with two or more rows of more preferred hosts such as collard and mustard can delay or prevent the dispersal of diamondback moth into cabbage crops. Crucifer transplants are often shipped long distances prior to planting, and diamondback moth may be included with the transplants. In the United States, many transplants are produced in the southern states, and then moved north as weather allows.