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Tomato Hornworms: How to Identify, Control, and Prevent Them

Image Credit:
Amanda Hill
Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

Big, green, and hungry—tomato hornworms can wipe out your tomato crop almost overnight. These giant caterpillars love to feast on tomato leaves and fruit, and they won’t stop there. Peppers, eggplants, and potatoes are also on their menu.

”This one is nobody’s friend if you’re a gardener and like to grow tomatoes,” says entomologist Jeff Smith, curator of the Bohart Museum of Entomology’s Lepidoptera collection.

The good news is that these pests are easy to spot once you know what to look for, and they can be controlled without resorting to harsh chemicals. In this guide, learn how to identify tomato hornworms, understand their life cycle, and discover effective natural ways to get rid of them—plus tips to keep them from coming back next year.

🐛 Hornworms munching your tomatoes? Our Almanac Garden Club members get exclusive pest guides, expert webinars, and practical tips to protect their crops. Protect Your Garden Now.

What Are Tomato Hornworms?

If you’ve ever walked out to your tomato plants and found bare stems where lush foliage used to be, chances are hornworms were at work.

  • The tomato hornworm (Manduca quinquemaculata) and the closely related tobacco hornworm (Manduca sexta) are garden pests found throughout most of the U.S. and southern Canada.
  • Both species feed on plants in the nightshade family (Solanaceae): tomatoes, eggplants, peppers, tobacco, and potatoes.
  • Because of their size and appetite, a small number of hornworms can defoliate plants quickly.

These pests are the larval stage of large night-flying moths (sphinx or hawk moths).

Tomato Hornworm crawling on a tomato vine.
Tomato troublemaker in action—meet the tomato hornworm! Photo by Amanda Hill.

Identification

How to Identify Tomato Hornworms

Look for big, green worms on tomato plants! Hornworms are some of the largest caterpillars in the garden. Key features include:

  • Color: Pale green with V-shaped white markings along the body
  • Horn: Dark, pointed “horn” protruding from the rear
  • Camouflage: Blends almost perfectly with tomato leaves, making them tricky to spot
  • Size: Can reach up to 4–5 inches in length

Tip: Inspect your tomato plants daily. Check the undersides of leaves for eggs and watch for early signs of feeding damage.

Tomato Hornworm vs. Tobacco Hornworm

Both species damage tomato plants, but here’s how to tell them apart:

  • Tomato hornworm: White V-shaped markings; black horn
  • Tobacco hornworm: Diagonal white stripes with black spots; red horn
tobacco hornworm
Can you tell which hornworm this is? 
(It’s a tobacco hornworm! Notice the white stripes with dotted black lines and a red “horn.”) 

Signs of Tomato Hornworm Damage

  • Chewed or missing leaves, often starting at the top of the plant
  • Wilted stems and bare stalks
  • Dark green droppings (frass) on leaves or soil
  • Chewed fruit and sunscald on tomatoes (caused by loss of leaf cover)

Tomato Hornworm Life Cycle

Understanding the life cycle helps you prevent infestations:

  1. Eggs: Laid on undersides of leaves in late spring; hatch within 1 week
  2. Larvae (hornworms): Feed heavily for 3–4 weeks
  3. Pupae: Burrow into soil to overwinter in a cocoon
  4. Adult moths: Five-spotted hawk moths emerge in spring to repeat the cycle

In warmer regions, there may be two generations per year.

Tomato hornworm moth (female)
Tomato hornworm moth (female). Look out for the moths in late spring. Photo by Didier Descouens/Wikimedia Commons.

Control and Prevention

How to Get Rid of Tomato Hornworms

1. Handpicking

  • The most effective method for small gardens:
  • Check plants daily and remove caterpillars by hand
  • Drop them in soapy water, or feed them to backyard chickens

2. Use Organic Controls

  • Bacillus thuringiensis (Bt): A safe, natural bacterium that kills young caterpillars (must be ingested).
  • Neem oil or insecticidal soap: Can work on small caterpillars, but less effective on large hornworms

3. Encourage Natural Predators

  • Parasitic wasps lay eggs on hornworms (you may see white cocoons attached)
  • Ladybugs, green lacewings, and birds also feed on eggs and larvae

If you find a hornworm covered with white cocoons, leave it—the wasps will do the control work for you

A tobacco hornworm covered with parasitic wasp eggs.
Nature’s drama! A tobacco hornworm becomes a nursery for parasitic wasps.

How to Prevent Hornworm Infestations

  • Till soil in fall or spring to destroy overwintering pupae (up to 90% mortality)
  • Rotate crops—avoid planting tomatoes in the same spot year after year
  • Use companion planting: Interplant dill or basil to deter pests; plant marigolds at borders
  • Attract  beneficial insects  by planting nectar-rich flowers

Frequently Asked Questions

Do tomato hornworms bite?
No. They look intimidating, but they cannot sting or bite humans.

What does a tomato hornworm turn into?
A large five-spotted hawk moth, also called a sphinx or hummingbird moth.

When do tomato hornworms appear?
Eggs are laid in late spring, and larvae are most destructive from June through August.

Can tomato hornworms eat other plants?
Yes. They also feed on peppers, potatoes, eggplants, and tobacco.

More Help for Gardeners: See our Garden Pest and Disease Library for tips on other common problems.

Do you have tomato hornworms? How do you handle them in the garden?

Garden Pests

About The Author

Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann loves nature, stargazing, and gardening so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website, and is also a certified master gardener in the state of Indiana.

Read more from Catherine Boeckmann

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Comments

<span>Sarah</span> Thu, 08/18/2022 - 21:17
Hornworms eating my tomato plants is very offensive. Regardless how pretty or ugly. I spend alot of time and money to grow veggies. Dropping the worm into soapy water is not cruel and neither is slamming them onto the pavement.
<span>Jeremy</span> Mon, 08/08/2022 - 12:34
In my garden…Tomato and bell pepper lives matter too. Actually, the tomatoes and bell peppers feed my family. So, they matter more. I’m all for teaching these pesky Horned Caterpillars to blow soap bubbles from their little mouths. Death to horned caterpillars.
<span>Tammy</span> Sat, 02/25/2023 - 22:18
I will stir up a fire ant nest and then drop the horn worms on top of the mound. And the ants work the worms over. And sometimes a mocking bird will eat the worms.
<span>Aurora</span> Sun, 09/04/2022 - 01:54
I found a huge green caterpillar on my tomato plant. It was green full of my tomato leaves. Those flowers of those future tomatoes, were supposed to feed me this summer/fall. I lost some big beef tomatoes bc if it. Nevertheless, I didn't kill it, thinking; it would turn into a beautiful butterfly, my favorite insect. In this article I learned the truth...it will turn into a moth. Don't like moths. Anyway, I broke the branch and threw it outside of my property. After that experience, I took the tomato plants and house them into my little green house. The green house has a window which I leave open for ventilation. Is there a chance that a moth will get at my Peppers and Tomatoes there too? I have planted basil, dill (young onions) and Rosemary and also a pot of lavender. Will those herbs/plant keep pests away?
<span>Scott Mccollum</span> Sun, 08/07/2022 - 15:11
I have marigolds planted next to My tomato plants and just pulled 3 hornworms off one plant so if Marigold deters them I would hate to see how Many I would have had. Not sure they deter hornworms.
<span>Kl Rich</span> Sat, 07/23/2022 - 23:31
When I see black dropping around my tomato plants, I quickly try to hand pick all the tomato horn worms I can. After the sun goes down, I’ll take a black light flash light and typically find more. Once I shine the black light flash light on one, they look blue and really stand out.
<span>John</span> Sun, 01/01/2023 - 11:39
We usually only find a couple horn worms a season, but with 50-75 tomato plants in our garden it’s possible we are overlooking a couple. Lol. The black light is a great idea that I’m going to have to try this year. Thank you. Good luck to all in your next growing season.
<span>Anne</span> Sat, 07/16/2022 - 11:01
make sure the caterpillar is not a monarch caterpillar; or swallowtail' the caterpillars look so similar; ty~
<span>Jay</span> Mon, 06/27/2022 - 15:52
I use a wooden clothespin to pull the tomato worms off. Takes a minute or two to see them. Best tip is the leaves. If they are disappearing, look for the tomato worms. Then into a cup and to the birdfeeder/ bird bath with them. Wild birds enjoy them. When I had chickens we use to call it chicken football. The chickens love eating them. Check your tomato plants often.
<span>Mp</span> Sat, 07/23/2022 - 15:34
Great suggestion!!! I am no longer squeamish, however.