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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

<a title="View user profile." href="/author/editors">The Editors</a> Mon, 04/20/2015 - 14:17

Perhaps it is a cutworm? These are usually nocturnal, but they cut through the base of young plants. Check this page for more information and photos:

http://www.almanac.com/content/cutworms

 <span>Don Zeiss</span> Mon, 09/22/2014 - 18:01
I have found neem oil to be very effective,for horn worms, and other leaf eating and sucking insects. It is probably the safest. It is not instantaneous. It causes worms to forget to eat,as well as many other symptoms. It is not harmful tobeneficials, because they dont eat or suck the leaves. youmight smother them though, so spray later in day, when they're not active. I live in sacramento, it gets quite hot here summmertime, no adverse effects so far, on my tomatos. most organic treatment I think. you don't even need protective clothing. It is effective in very small concentrations.
<span>Rogersan</span> Mon, 09/08/2014 - 21:27
I would feed any I pick to my chickens and watch the madness ensue. So far I have not had any horn worms but the stink bugs were a real menace this year. Perfect tomatoes with little black dots and they taste bad wherever they are poked at. Ended up having half a harvest due to a watering issue and the stink bugs. I think better weed control would have helped.
<span>Donna6087</span> Mon, 09/01/2014 - 08:09
My tomato plants are healthy, and produced many flowers and tomatoes. They were so heavy with tomatoes that the cages fell over and had to be propped up. As I pick the tomatoes, I'm finding about half of them have a little black worm in them. I've seen these around the yard all the years I've lived here, and this is the first time I've seen them in the tomatoes. The live worm curls in a circle and it's about 1/3 inch long. The beefsteak tomatoes are ruined and half the Romas are infested. The cherry tomatoes have a few, but they fared the best. How do I protect against these in the future? They've never been a problem in the past
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 09/02/2014 - 09:53

Hi, Donna,

It sounds like the tomato pinworm. These overwinter in soil, especially that of greenhouses. The first recommendation is "clean soil." (Don't we all think we've got clean soil?) Essentially, if you buy transplants, get your tomatoes from a trusted source. Keep your garden clean last season's plant refuse. Rotate your crops.

If you see evidence again (small holes in the leaves, for example), remove the leaves from the plant. If you see holes in the tomatoes in season, use any that are edible and dispose of the remainder.

We hope this helps.

 <span>Carole Westgaard</span> Mon, 08/04/2014 - 23:31
I'm in the Boulder, CO area and I've never seen hornworms as big as here! Moved here from Illinois last year and had them there, too. I have Marigolds all over the place right next to the tomatoes and basil less than a foot away - tons of it. Nothing helps except picking them off although I haven't tried the Bt stuff - afraid to!
<span>Anita Dot</span> Tue, 04/28/2015 - 05:03
bT is safe and it works. One bite and they stop feeding. It works on all kinds of caterpillars, not just hornworms. Spray seems to not be the problem since you can wash it off,and it is in the soil naturally in small amounts, but when it is used in corn or other seeds as a GMO not so sure that it is safe.
<span>Savannah Starr</span> Fri, 09/12/2014 - 22:31
I just seen one for the first time today and was bigger then a bic lighter and long ..
<span>Jamie Bowen</span> Sat, 09/27/2014 - 16:16
I also just saw my first one ever!! Thought it was some kinda mutant caterpillar lol
<span>Hollynanaof11</span> Wed, 08/06/2014 - 19:53
Last year when I noticed that I had tomato hornworms feasting on my tomatoes, I picked and destroyed what I could find. Later, after dark, I went out in the garden armed with a blacklight on an extension cord, and lo and behold those that I missed lit up like neon lights among the leaves! Easiest way I know to get rid of the little beasts!