Preventive Control

Natural enemies

Parasitoids

1. Braconid
2. Native parasitic wasps and flies
3. Tachinid fly
4. Trichogramma

Predators

1. Assassin bug
2. Lacewing
3. Ladybird beetle
4. Weaver ant

Monitoring

Monitor the crop regularly to look for the larva. A larva is usually found resting along the main leaf vein, on the center of the plant, and on the fresh green piles of frass. A closer look is necessary because the larva camouflages with the leaf.

The general recommendation for when to implement a control measure is when there is 1 larva or a 1 new feeding hole in every 10 plants during the early head formation (Griffin, 1999).

The recommended sample sizes are: 20 plants for eggs; 30 plants for young larvae; 40 plants for mid-age larvae; 50 plants for large larvae; and 70 plants for pupae (Capinera, 2000).

Cultural and management practices

1. Practice crop rotation with non-cruciferous crops.
2. Plow- under all plant resides after harvest. This will expose larvae and pupa to predators and sunlight.