European Corn Borer
A pale flesh-colored caterpillar with a dark brown head that tunnels inside stalks, stems and fruit. Young ones chew rows of small holes in unrolling leaves; older ones disappear inside the plant where you cannot reach them.
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.
1Clean up stalks in fall
Chop and remove or turn under corn stalks, pepper stems and weedy grass stems after harvest, since the caterpillars spend the winter inside them.
Try this first2Plant early
Early corn is usually past the vulnerable stage before the first generation of caterpillars is looking for a stalk to enter.
3Check the whorl and treat early
Look into the leaf whorl of corn and at the growing tips of peppers; if you find small caterpillars there, a Bt or spinosad product will reach them.
bt thuringiensis caterpillar spray4Pull and destroy bored fruit
Pick off any pepper with a hole under the cap and get it out of the garden so the caterpillar inside does not finish its cycle there.
As an Amazon Associate, Story Thyme Farms earns from qualifying purchases, at no cost to you. It never changes what we recommend.
Which plants get european corn borer
Every plant we cover that gets european corn borer, 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.
vine1
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 Poaceae, with 2 of the 5 affected plants.
- Poaceae2 plants
- Solanaceae2 plants
When to treat
Act during the moth flights in late spring and again in midsummer, while the caterpillars are still feeding on the outside of the plant, because once one is inside a stalk or a pepper no spray reaches it.
Timing only — the label is the law
This page tells you when to watch for european corn borer 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 european corn borer, 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.