Corn: Corn earworm
Photo by: A.L. Antonelli
Biology
The corn earworm is the caterpillar of a light to dark brown moth with a 1 1⁄2″ wingspan. The caterpillars are up to 1 1⁄2″ long at maturity. They vary widely in color, but typically have darker stripes along a cream-colored to greenish body.
The first generation may feed on the center shoots of the corn, attacking the tender new leaves. Later generations may feed on the silks, preventing pollination. They may also feed in the ear itself, damaging kernels and leaving behind dirty-looking droppings. The droppings may be visible at the tip of the ear.
Several generations may occur in one season, as the corn earworm can progress from egg to adult moth in as little as one month during favorable conditions. Corn earworm pupae overwinter in the soil. Peppers, tomatoes, beans, and many other plants are also attacked.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Varieties with tight husks (such as ‘Country Gentleman’, ‘Golden Security’, ‘Silvergent’, and ‘Staygold’) are more resistant to damage.
- Early-season plantings (before April) are less likely to be damaged.
- In small plantings, a clothespin placed at the point where the silk enters the ear can prevent earworm access. Place clothespins soon after the first silk is seen.
- Plow or dig up corn plots in the fall to kill overwintering pupae and prevent emergence of adults in the spring.
- Encourage natural enemies such as green lacewings, parasitic wasps, and other predators.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Apply first application when silks first appear.
- Follow label instructions on reapplication intervals.
- Direct insecticide application to silk.
Approved Pesticides
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
Additional Image
Photo by: Unknown
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