Corn Earworm
A striped caterpillar that can be green, pink, tan or nearly black, with a pale head and a bristly feel. It eats into the thing you wanted to pick: the tip of a corn ear, a green tomato, a bean pod, an okra pod.
Pest checklist
Four things to look for. If most of them match what you are holding, you are in the right place.
What gets rid of them
Gentlest option first. For most backyard cases the first one is enough, so try these in order and stop as soon as it works. If you do spray something, the product label tells you how — please read the notice further down.
1Plant early and pick early
Early sweet corn and early tomatoes finish before the big midsummer moth flights arrive, so they take much less damage.
Try this first2Oil the corn silks
Put a few drops of plain mineral oil on the silk tip of each ear about five days after the silks emerge, once the silks have started to brown.
food grade mineral oil3Cut the tip off
If only the ear tip is chewed, snap or cut off the top two inches at harvest; the rest of the ear is fine.
4Spray Bt on small caterpillars
A Bt or spinosad product on the silks or on fruiting vegetables catches the caterpillars while they are still on the outside of the plant.
bt thuringiensis caterpillar spray
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Which plants get corn earworm
Every plant we cover that gets corn earworm, grouped by type — tap any one to open its page. A note beside a plant came from that plant’s own entry, because the same pest can be a minor nuisance on one plant and a serious problem on another. Plenty of plants we do not cover get it too.
Plant families hit hardest
Related plants often share the same problems, so if one plant in a family has it, check the others. The largest group here is Solanaceae, with 3 of the 10 affected plants.
- Solanaceae3 plants
- Brassicaceae2 plants
When to treat
On corn, treat the silks a few days after they appear, because once a caterpillar is down inside the husk nothing you spray will reach it; on tomatoes and beans, pick the caterpillars off as you find them.
Timing only — the label is the law
This page tells you when to watch for corn earworm and when treating is worth considering. It is not a recommendation to apply any particular product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.
- Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
- Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
- Confirm the product is registered for your crop in your state. This page groups many different crops together, and a product legal on one of them is not legal on all of them — state registrations differ too. Your state pesticide agency or local extension office can confirm both.
- Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.
Other problems on the same plants
If a plant gets corn earworm, these are the problems it most often gets as well, so they are worth checking for while you are out there. They tend to appear together; one does not cause another.