Preventive Control

Natural enemies

Parasitoids

1. Cotesia
2. Tachinid fly
3. Trichogramma

Predators

1. Ground beetle
2. Hoverfly
3. Lacewing
4. Minute pirate bug
5. Rove beetle
6. Spider
7. Weaver ant

Monitoring

Monitor the presence of natural enemies. The pests can be controlled by the beneficials and by insect pathogens until heading (Capinera, 1999). The seedlings or small plants need treatment if the population of medium-sized to large caterpillars are large enough to stunt plants' growth. Before heading, well-established plants do not need to be treated unless there are more than 9 small- to medium-sized larvae per plant. Treat just before heading or at Brussels sprouts formation if counts show more than one looper or other caterpillar in 25 plants. (University of California, 2003).

Management and cultural practices

1. Plant resistant varieties. Green cabbage varieties are found to be resistant to cabbage looper attack while red cabbage varieties are less preferred by the pest (Missouri Botanical Garden, 2003). Ask for assistance from local agriculturist office to obtain cabbage looper resistant cultivars that are available in the local markets.
2. Remove and destroy all the plant debris after harvest. The pupae might still be in the plants.
3. Plow and harrow the field after harvest to expose pupae to sunlight and predators.
4. Clear the surrounding area of weeds, which may serve as alternate hosts for the pests.