The Tomato Horn Worm and/or Tobacco Horn Worm are very similar in appearance. Tomato hornworms have eight V-shaped marks on each side and a blue-black color “horn”. Tobacco hornworms have diagonal white stripes and a red “horn.” These hornworm caterpillars are pretty small at first and hard to see because of their pale green color, but they become huge – 3 1/2 to 4 inches (7-10cm) in 3-4 weeks. You can’t miss them then!
Tomato Hornworm-(left) Paul M. Choate – University of Florida, Tobacco Hornworm-(right) Colorado State University,
Tomato/Tobacco hornworms are the larval stage of a huge moth called five-spotted hawkmoth, sphinx moth, also known as hummingbird moths. Approximate size of the moth is around the size of a hummingbird so you can’t miss them. The hawkmoth is gray-brown with yellow spots on the sides of their body. Hornworm eggs are green and are laid on the underside of leaves.
Five-spotted hawkmoth (left)-Floridagardening.com, Hornworm Pupa (cocoon), Hornworm Egg (right)-Colorado State University
Hornworm Lifecycle
The five-spotted hawkmoths lay their eggs as soon as they mate after hatching. They appear in late June to August. Full grown larva (3-4 weeks feeding) wander around the garden digging themselves in where they form a pupa (brown and about 3cm long) that overwinters and hatches in the spring.
Hornworm Damage-Floridagardening.com
Hornworm Damage
Tomato Hornworms feed on leaves and stems of tomato plants. Ocassionally they will also eat the fruits later in the summer months. They also feed on peppers, eggplant and potatoes. They can defoliate a plant in just a few days. There can be two generations of tomato hornworms every year. A bunch of them can spell disaster in your garden!
How To Control Tomato Hornworms
- Use a liquid Bt spray like Green Steps Caterpillar Control
Bt (Bacillus thuringiensis) does not harm animals, people or the environment. It paralyzes the horn worms and they die from starvation. Spray the top and bottom of the tomato plant leaves. Repeat every 5 to 7 days until you don’t see anymore worms. Bt is safe to use right up to the time of picking your tomatoes. - Another all-natural environmentally friendly pesticide that is safe for use around kids and pets is Plant Guardians Houseplant Insecticidal Soap
Spraying the undersides of the leaves with an insecticidal soap mixture kills the eggs at the first sign of seeing the moths. A hard spray of water will also help if your plants are strong enough. Wiping the eggs off with alcohol on a q-tip is also effective. - Introduce Parasitic Wasps into your garden
Parasitc Wasps (Braconid and Trichogramma) lay their eggs on the larva. If you see little white things on the worm don’t kill the worm, place it in a jar with a fresh leaf and keep feeding it until the wasps do their job. These are the cocoons of the wasp and their larva feed inside the host and will kill it. This guy below has just met his maker!
Hornworm with parasite eggs (left)-Joe Boggs, Braconid Wasp (right)-Perdue University - Hand Pick
Tomato Hornworms are so big you cannot miss these guys. If you don’t want to touch them I recommend cutting them in half with the kitchen scissors. In the fall when you turn your garden pick out any pupae (cocoons) you might find and destroy them. - Companion Planting
Plant marigolds as a deterrent around or between your tomatoes. Marigolds stink to a lot of different bugs and they avoid them.
i cant tell if my tomatoe worm is dead its getting darker and it still stays bent when you move it. hut it still feels mushy though and i still have a feeling that its still alive but i dont know what to do
Very interesting to read all the comments of those for and against the horn worms. Our family first noticed the gorgeous huge sphinx and hawk moths hovering around our flowers. They really do look like hummingbirds when you first see them. And of course as moths, they do in fact pollinate plants. We absolutely love those moths–one of the coolest insects on the planet as far as we’re concerned.
As much as I feel for those of you trying to grow a garden, now that we know that the horn worm (both the tomato and tobacco) turn into the sphinx and hawk moths, we’ll never harm one of those giant green caterpillars. As a matter of fact, we just saved one from a friend who was going to feed him to her chickens. He was great-big and green, so we named him Hulk–naturally enough. He ate about half of a red grape pretty quickly but didn’t seem all that interested in the other things we put into the container for him (wheat germ, dandelion greens, a mint leaf, slice of bell pepper and slice of tomato). And the very first evening we had him (last night), he buried himself under the soil we put into the container. We are looking forward to him coming out in his new duds–and releasing him so that he can pollinate fall flowers.
Here’s something I read on another site that might give folks a little different perspective–
“I happen to fall into that category of gardeners who don’t mind the nightshade-eating Manduca hornworms. While one can do some damage to a young plant, here in central Oklahoma, nature sends them late enough in the season, to ensure plants are well-established in their growth and foliage. Since hornworms also find the tender suckers as well as leaves, this pruning is beneficial to force more fruit, less leaves.
Our Manduca hornworms here are largely endangered, and I do NOT recommend or condone the killing of pupae or moths. We have too many tachinid flies [a non-native parasitoid and responsible for wiping out over 33 native giant silk moth species].
I strongly advise Oklahoma gardeners to give live hornworms to teachers and home schoolers to rear indoors for education. If a larva dies, it needs to be destroyed as it’s full of tachinid maggots.
By the way, in your picture of the adult M. quinquemaculata moth, the flower is not a morning glory, but a Datura moonflower. The relationship between the Datura and Manduca’s is completely mutualistic, too. This is one valid reason we need our sphinx [hawk] moths!”
Hi every one!
I live in Mallorca Spain and this morning I found my first ever Hornworm which was walking across my path in the woods Wilst I was out walking my dogs.
What a beautiful little creacher it was and I feel lucky to have seen it!
About tree weeks ago I had the biggest hawk moth (humming bird moth) in my loung which was wonderful to see.
i have a huge green worm eating ny lilac bush -i have tomatoes and moon flowers-has anyone ever had a tom worm on lilacs
I found about 10, 2 1/2 to 4′ long on our tomataos. The dear ate the plants, so im going to let them grow and show my children, 2 and 3 1/2, the life cycle. I think they are awsome to look at, next year we will plant plants that keep them away, rather then kill them or hurt them. I try to teach my children to not harm animals, and enjoy the ones you can watch grow. We also have giant praying mantis all over.
I just caught a hawkmoth that must have just emerged because his wings were still small. I picked him up and put him in my pet toad’s cage. I couldn’t believe it when my toad hoovered it in about 10 seconds! He is a small western toad, with a HUGE appetite. He can eat about 10, one-inch roaches a night!
The little white things on the horn worm is from a parasite from a wasp. They turn into a pupa, Then next year a beautiful Moth. I did not have any horn worms on my tomatos at all. I have moon flowers. They like the moon flowers.
Found only two recently. Both were about 2″ long but, one was covered with white eggs! Disposed of them and ….. none since. My guess is getting ride of the ones carrying the eggs helps to eliminate the evil tomato lovers.
Those little white things are called trichogramma wasp eggs. I just found one now. Really ugly things. Going to get some spray.
I use to BUY these worms at the reptile store when i could get them and fed them to my bearded dragon lizard. If you have a pet store nearby you may be able to cash in on those suckers!!
I was fascinated by them at first….oddly..after years of growing tomatoes….this is the first time I have encountered them..but man..they do so much damage..destroyed my entire beefstake plant..picked off about 6 so far..just throw them in the grass for the birds…but might try to grow one into a moth now that I know what they become….good site..glad I found it..thnx…
I just scraped off 8 big ass worms and put them out in a pile of bird seed . Bon apetite birdies .
gezz, I thought a grasshopper was eating my leaves , went back the next day and the whole pepper plant leaves were stripped clean, the big buggers even took big bites out of some of the peppers.Looked at my cherry tomato plant which was doing incredible, and noticed ALL the top of the plant the leaves were being stripped off it. I did locate 3 worms ( UGLY ) and removed them. will look to see if I can locate any of the pupa. Thank everyone for all the information and also this very informative web page. Thank-you.
A family member told us that corn starch sprinkled on the plants will run these suckers off. We tried it on our tomato plants and it worked great. Did not think about them getting the pepper plants but came home tonight and discovered all our pepper plants stripped of leaves and found only 1 worm on the last plant. Sucker got squished. Re-treated the tomato plants just to be safe.
A simple and humane solution is to pick them off and place them in an old jar, or whatever you have around and place them in the freezer, this is a method of humane euthanasia. Once they are frozen, throw them to the birds or in the garbage or whatever makes sense for you.
I hate those things.
BT , a non toxic bacteria is good to deal with the larvae. It makes them feel full so they stop eating. Azatrol is a natural product from neem oil that works in multiple ways against multiple vile insects.
Apply either or both as soon as you plant tomatoes and then weekly. Don’t wait until you see a caterpillar.
Hi,People.My friend and I saw two of these little suckers on my tomatoes after find it destroyed one plant.My friend poked it with her finger and it bit her.Then She poked it with a stick and it litteraly attacked the stick.It made us so mad that we got them on the ground and squished them until they DIED.teehee
the moths are beautiful what I do is soon as I see droppings or start to notice I go around and pic them with the leaf they are on! they sometimes will die within a day or so but being the insane person I am I remove the non producing stems and leaves of my tomato plants and put it all in a bucket and feed them. if you are trying to conserve water this is good idea as the non flowering stems will need to be reduced anyway, then I move them somewhere else. I think it is worth it because the giant moths are beautiful! I like the comment on planting the moon flowers so the tom worms leave them alone will try that!! the white powdery things are probably aphids and believe it or not ants herd and milk them! but they are a disaster!
They make great fish bait! One day and 3 entire branches were eaten off. :p … The bright side is that fish taste good. 😉
Frankly, these bugs disgust me. I’ve found two on my tomato plant, which they totally destroyed. They were almost parallel to each other on the same little branch, but I didn’t notice them right away. And I found another one, more recently, on one of my bell pepper plants, eating my big bell pepper. Needless to say I was pissed.
Both times these monsters were killed. Pried off of the plant with a stick and then smashed with said stick. And then I found another bug, a normal, smaller caterpillar that was very fuzzy, eating my strawberries. That one died too. I cannot stand bugs being in my garden. I swear they’re out to get me though.
Dear people I am 13 and amused by the argument and I’m sure many other people are too. But there is a time when all fun things have to come to an end. To Sami I do think it is a bit rude of you to insult Renee as you did you can do whatever you want to with them. I however, am keeping mine as a pet until it metamorphosises 😊. Although I do not have any tomatoes so I guess I don’t know the pains of having tomatoes. I found it on some tree in my backyard. I am not exactly sure how it got there I live in the city and there isn’t a farm with tomatoes for miles around so if anyone has any ideas how it got here please tell. Laters!
My veggie garden is on the side of the house and so far worm-free. However, my flowers in the front yard are being eaten alive by these little green worms. I had no idea they ate such a variety of plants. One or two years ago, I found a worm on a basil plant (which was also away from my garden), but thought it was a fluke. Now I know it wasn’t. I have a nice bright variety of petunias, and they are eating both the leaves and the petals. Of course they blend in beautifully, but I intend to pick them off when I see them to preserve the color. If I find too many more, I may use one of the remedies mentioned.
I can identify with the destruction that these creatures can cause. Last year (2011) my boyfriend and I planted about 40 tomatoe plants of various varieties along with several dozen pepper plants and other plants and all our tomatoes and peppers were destroyed by these bugs. By the time we found them, it was too late and we lost 80% of our crop. We even had used Sevin dust to protect the plants but it didn’t work. It was bad enough that on top of that the rest of our crops didn’t do too well either like many others in our area. Everyone in our area complained of poor yielding crops aside from the plant munching bugs. Hopefully this year will be kind to us and will yield us bountiful crops. We not only feed ourselves, but try to grow enough to give to others in our family, neighborhood and friends as well with our crops.
We found 4 of these giants amoung our dozen or so tomato plants. I hope we discovered them soon enough that the foliage can recover. Our’s are the tobacco variety with the straight white lines and are without the wasp parasites. I have isolated them with trimmings to estimate their verocious appetite.