Preventive Control

Natural enemies

Parasitoids

1. Braconid
2. Tachinid fly
3. Trichogramma

Predators

1. Hoverfly
2. Lacewing
3. Ladybird beetle
4. Minute pirate bug
5. Praying mantis
6. Spider
7. Weaver ant

Monitoring

Monitor plant growth throughout the growing season to observe crop conditions and to recognize the potential corn borer attack. To monitor, start looking for corn borer egg masses when the plant is a month old. The egg masses are found on the surface and underneath the leaves near the midrib. Randomly select 50 plants and count the total number of egg masses and multiply by 2 to obtain the number per 100 plants. The critical levels of corn borer are: 40% of plants are infested during whorl stage; 3-4 egg masses/100 plants are found; and 40% of the remaining tassels are infested after detasseling (Bureau of Plant Industry, 1987: pp. 10-17).

Management and cultural practices

1. Practice proper plant spacing within the rows. Sow 1-2 seeds per hill. Crowded plants are difficult to weed, to fertilize, and to monitor crop condition.
2. Practice crop rotation. Grow leguminous crops as rotation crops. This will improve the soil structure; destroy the weeds and corn borer lifecycle.
3. Plant together with other farmers. Late or early planting will provide stem borer an environment for their continuous breeding activities.
4. Practice proper field sanitation. Corn borer laid their eggs on grasses and weeds surrounding your field. Ideally, all crop residues should be cut for animal feeds immediately after harvest. The remaining stubbles should be burned and be plowed under.