Tomato Hornworm
Pest · Commonly affects: Tomato, Pepper, Eggplant, Potato, Tomatillo
The tomato hornworm is the large green caterpillar (larva) of a night-flying moth in the sphinx or hawk moth family, most common on tomatoes and their relatives across the United States. Gardeners care about it because a single caterpillar eats a surprising amount of foliage very quickly and can strip a plant or scar fruit almost overnight.
How to identify it
Look for a plump green caterpillar up to about 3 to 4 inches long, with diagonal white V-shaped or bar-like marks along each side and a soft, curved black or bluish horn at the rear end (it does not sting). Its green color blends in perfectly with the leaves, so the easiest clues are usually the damage plus the dark pellet-like droppings scattered on lower leaves and the ground. The similar tobacco hornworm has white diagonal stripes and a reddish horn; both are managed the same way.
Damage
Hornworms chew large ragged holes in leaves and can quickly defoliate whole stems and growing tips, leaving bare branches near the top of the plant. They also gouge shallow scars and open wounds on green and ripening fruit, which reduces yield and creates entry points for rot.
Prevention
Rotate tomatoes and other nightshade-family crops to a different bed each year so overwintering pupae in the soil emerge without an easy host nearby. Give plants full sun and adequate spacing for airflow and easier inspection, and keep the garden free of weedy nightshades that serve as alternate hosts. In fall, lightly cultivate or turn the top few inches of soil where tomatoes grew to expose and destroy the brown, spindle-shaped pupae before the next moth generation.
How to manage it
Handpicking is the most effective control in a home garden: scout plants every day or two, especially the upper foliage, and drop any caterpillars you find into soapy water. If you see a hornworm covered in small white rice-like cocoons, leave it in place, since those are the pupae of a parasitic braconid wasp that will kill that caterpillar and produce more beneficial wasps. Encourage other natural enemies such as lacewings, lady beetles, and paper wasps by avoiding broad insecticides and keeping some flowering plants nearby, prune out and remove heavily chewed or fouled tissue, and water consistently at the base so plants stay vigorous enough to outgrow light feeding.
General guidance for US home gardens, focused on prevention and non-chemical control. For a confirmed diagnosis and options specific to your area, contact your local Cooperative Extension office. Page updated Aug 4, 2026.