Organic Corn Earworm Control

If you see small green worms wriggling around on your corn, chances are they’re corn earworms. Learn how to prevent corn earworm damage and naturally treat infected crops.

| April 16, 2013

This article is part of our Organic Pest Control Series, which includes articles on attracting beneficial insects, controlling specific garden pests, and using organic pesticides.

Corn Earworms (Helioverpa zea)

The most common of sweet corn pests, corn earworm larvae are frequently found feeding in the tips of sweet corn ears. Organic corn earworm controls include choosing vigorous varieties with tight husks, treating ear tips with vegetable oil or a Bt pesticide, or simply breaking off the damaged part. Native to the Americas, corn earworms are now found throughout the world, especially in temperate regions where this sweet corn pest survives winter.

What Are Corn Earworms?

Most gardeners see this sweet corn pest in the first season of growing corn. The corn earworm is the larvae of a mottled tan night-flying moth common throughout North and South America. Corn earworms are most damaging to corn, but they can also bore holes into tomatoes, beans, peppers and a few other garden plants.

Most earworms are muddy-brown caterpillars, but they may be green, yellow, pink, reddish brown or dark gray. Fleshy caterpillars found feeding in the tips of ears of corn are probably corn earworms.

What Corn Earworm Damage Looks Like

Mother moths lay tiny eggs on the emerging silks of corn ears, and from there the larvae hatch and burrow through the silks and into the tops of the corn ears. When you shuck the ears, one or more caterpillars may be found at the tips. In severe cases, this sweet corn pest feeds on the middles of ears as well.

On tomatoes, earworms feed initially on the foliage and save the juicy fruits for dessert.

mother earth news fair 2018 schedule


Next: April 28-29, 2018
Asheville, NC

Whether you want to learn how to grow and raise your own food, build your own root cellar, or create a green dream home, come out and learn everything you need to know — and then some!