How to Control Corn Earworm

Vegetable gardeners are very familiar with the destructive corn earworm and the havoc it causes in the garden. Not only do these worms destroy ears of corn, they also feed on cotton and tomatoes. Controlling the adult moth before she lays her 3,000 eggs on ears of corn is crucial to preventing an infestation.

Difficulty: Moderate

Instructions

1. Till the garden soil in the fall and spring to disturb the pupa's developmental cycle. Weather, wind or birds will kill the exposed pupa.

2. Observe the developing ears of corn for signs of infestation, such as active larvae, eggs or excessive excrement on the corn tassel. Pick larvae off plants and squash them or drop into a bucket of bleach.

3. Suffocate unseen larvae by applying an eyedropper full of mineral oil to the top of each ear of corn.

4. Determine the possible rate of infestation by catching adult moths in two pheromone traps placed along the moths' flight path. If five to ten moths are caught total in both traps on consecutive nights, then it is likely an infestation will occur that will need some type of pest control.

5. Kill eggs by releasing trichogramma wasps. The wasps will devour previously laid corn earworm eggs in the corn silk.

6. Take weekly preventative action by spraying the corn tassels with beneficial nematodes, dipel dust or insect spray until the silk turns brown. This should keep the larvae from developing on the ears of corn.

7. Remove and burn infested cobs of corn to destroy the larvae and eggs. At the end of the growing season, cut down and dispose of all cornstalks. Till the remains into the ground, destroying the key earworm larvae habitat.

Tips & Warnings

• When using a pesticide, follow the directions on the container. Occasionally, pesticide concentrations differ, which changes the way you apply it to the corn.