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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>Cabezon99</span> Mon, 07/29/2013 - 10:45
Sevin does not work, Sprayed and powdered, next day I find 2 more so I isolated them, sprayed them with sevin directly. They looked to be irratated but a day later they were alive and well pacing around the edge of the cage trying to escape.
<span>Susan Ethridge</span> Sun, 07/27/2014 - 09:55
So what did you use to get rid of the worms? I have rot spots on the bottom of my tomatoes. Does this have anything to do with the hornworms or is it some other problem? Thank you, Susan
<span>Tmartin256</span> Sat, 07/06/2013 - 23:55
A couple of things: Look for them at night using a UV flashlight. The worms are a brilliant green while the leaves are purple. Much easier to see. Also the worm feces is a very bright green. So if you see green spots on the leaves, go worm hunting. Don't use UV googles but DON'T LOOK AT THE LIGHT DIRECTLY! A very dilute solution of caffeine seems to deter them. Be carful applying to frequently as it can harm the plants. I'm going to try the BT method next.
<span>Amy Greenlaw</span> Wed, 08/28/2013 - 19:17
What is the BT method?
<span>Mmr</span> Sat, 07/06/2013 - 10:30
I have inspected my tomato plants almost dally looking for these horrible pests. Today was the first time I discovered them. They were at the top of the plant. One very large, about 2 inches long and the other one much smaller. I pulled them off and sprinkled the entire plant with Sevin powder. Do these warms grow large so large in a very short time. With my almost daily inspection, I am amazed at the size of them.
<span>Shauna Shuford</span> Wed, 07/03/2013 - 16:21
I will tell you that marigolds do not work to protect your tomato plants from Hornworms I had 2 plants surrounded by 6 flowering marigolds and the tomato plants were stripped by 3 hornworms in a day.
<span>Zadi</span> Tue, 07/09/2013 - 09:45
Tomato horn worms eat marigolds to. They ate my marigolds then my beautiful pepper plant. I found him, he was huge.
<span>Jill707</span> Fri, 06/28/2013 - 02:05
I found 5 red hornworms in my garden. I been planting tomatoes for the last 3 years and is the first time I found this suckers. So, tomorrow will be hunting day. Be aware because I will get those eggs. Thank you everyone for the tips.
<span>Christy H.</span> Wed, 06/26/2013 - 15:49
I too have these terrible worms!! They have eaten the tops of 3 large plants, I have picked them off and killed them as I see them. I think I will be going the route of using the BT insecticide treatment. I just couldn't believe how much of the plant these suckers ate before I found it! Unbelievable!
<span>Jacob Long</span> Mon, 06/24/2013 - 08:00
I recently had two of these on my tomato plant. What helps is put a stick up to them, then they will crawl up the stick. with them still hanging on to the stick walk to the closest ant bed and throw the stick with the worm still on into the ant bed. Then watch the FRENZY!