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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.

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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>Loriann B</span> Thu, 04/25/2013 - 14:30
HA HA HA Diann! Your comment made me laugh! :] I just looked up their adult form photo so I can kill them BEFORE they destroy my tomatoes!
<span>Nancy Lynn Lopez</span> Sat, 09/01/2012 - 14:51
so if i understand this correctly,if i have found 2 hornworms,chances are i will find many more?? i have never had this problem before in my garden,could they have been in the siol of the plant when i purchased them?
<span>Janice Stillman</span> Wed, 09/05/2012 - 12:26
Hi, Nancy, Thank you for your interest in The Old Farmer's Almanac. To answer your first question, yes, it's certainly possible that you will find more hornworms in your garden. Watch to see if the leaves on your tomatoes "disappear" (get eaten) and for black "droppings" (poop). You might even find that bites have been made in your tomatoes. As to whether they came in the soil, we can only offer a maybe. Just because you never had them before doesn't mean you'll never have them. Eggs are deposited on plant leaves and the mature larvae drop off into the soil at maturity. They dig into the soil where they form a pupal cell before attacking the plant. Sources suggest that tillage can eliminate as much as 90% of the larvae. So can crop rotation. One thing to note: if you see a hornworm with a lot of little "white things" on it that resemble grains of rice, let it live! The white things are parasites that will kill the worm and grow/emerge to become predator wasps. I hope this helps!
<span>Novicegardener…</span> Mon, 08/27/2012 - 11:59
I'm a novice gardener with a few herbs and tomatoes in my front yard. I'm surprised to hear about these plants that are supposed to keep the hornworms away. I have a very small garden and it contains one cherry tomato plant, along with two basils and two rosemarys, among others. I first noticed that some of my lower and inner leaves were wilting and dying, but I thought it was because I have to rearrange the plant pretty often to support it. It wasn't until today that I saw some stripped branches and huge hornworms. Now that I look at it, it seems like almost all of the inner leaves and up to a third of the outer leaves have egg pouches on them! What can I do? I don't want to kill bees, as they're the ones making my tomatoes possible. Is the pesticide the right choice for me? Most of the worms I found were parasitized, but it seems like there are too many for them all to get that. Thanks for your help! ~CarolAnn
<a title="View user profile." href="/author/editors">The Editors</a> Mon, 08/27/2012 - 17:31
Hornworms usually start at the top of the plant, eating interior leaves. Handpicking is probably best, since you have a small garden. Use gloves to grasp them and drop them into a bucket of soapy water or, if you can stand to, squish them. Gently scrape the eggs off the leaves and destroy them. If you can, it’s good to leave the parasitized hornworms alone so that the braconid wasps can hatch from the eggs; the caterpillars will die at that time. If this doesn’t work, BTK (Bacillus thuringiensis subsp. kurstaki) can be sprayed on smaller caterpillars; it will not affect bees.
<span>Novicegardener…</span> Mon, 08/27/2012 - 19:13
Thank you for the info! ~CarolAnn
<span>Nanamickey</span> Fri, 08/17/2012 - 07:20
We had 4 of these worms on our plants this year and I had never seen the wasp eggs on them in the past so I assumed they were their own offspring. They were completely covered with them. If I had known what they were, I wouldn't have thrown them in the firepit. Worked good to kill them! Next time I will just let nature take it's coarse and let the wasps hatch.
<span>Gardengurl</span> Tue, 08/14/2012 - 09:46
I have been gardening and growing tomatoes for years. This is the first time I have seen one of these owful worms and by the time I found it it had destroyed my tomatoes and eaten nearly all the leaves on two plants. This thing was as big around as my thum and about 4 inches long. I pulled both plants out and tossed the whole thing since I didn't know what it was or if there were others lurking around. I have never ever seen one of these on my plants before. Now I will be buying tomatoes until next summer.
<span>Gramma</span> Tue, 07/31/2012 - 07:04
I have tried every method the reader above have suggested for the last 10 yrs. None of them work except for 7 dust, and pluckin em off and giving them to the chickens. (they appreciate the ugly sobs)
<span>D.</span> Wed, 07/18/2012 - 11:16
If soapy water will take care of the worms when placed in it will it take care of them if I spray soapy water directly to the plant? Thanks