Look for chewed leaves, dark droppings on foliage, and stems stripped bare. The caterpillar has a horn at the rear. Search at dusk with a flashlight — their eyeshine helps — or scan the plant after you notice fresh frass.
What to do
- Pick them into soapy water or relocate far from the garden if you prefer.
- If a hornworm is covered in white cocoons, leave it. Those are parasitic wasp pupae; the wasp generation will hunt more hornworms.
- Bt (Bacillus thuringiensis) products labeled for caterpillars on vegetables can help on young worms; large ones are easier to pick.
- Clear nearby nightshade weeds that can host related moths.
After the damage
A defoliated plant can still set fruit if stems and some leaves remain. Water evenly and avoid a heavy nitrogen push that only makes soft new tips for the next moth. Spacing and airflow notes are on the tomato page.
Frequently asked questions
Will hornworms eat the fruit?
They prefer leaves but will scar green fruit. Removing worms promptly protects later clusters.