Tomato Horn Worms
Tomato Hornworms are the larva of a huge moth called five-spotted hawkmoth. 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.
Tomato Hornworm-(left) Colorado State University, Five-spotted hawkmoth (right)-Floridagardening.com
The 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! They are green-brown colour with v-shaped markings on the body and unmistakable ‘horns’. Hornworm eggs are green and are laid on the underside of leaves.
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 Step™ 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 Guardian™ 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.
August 26th, 2008 at 7:53 pm
my class has 1 how do i find out if it is a girl or boy
August 26th, 2008 at 2:25 pm
I myself took 27 tomato worms off my brothers row of tomoato’s and they were unaware of why their tomatoes were doing so bad. Right now I have the tomatoe worms in various jars and am keeping them for my 14 year daughter and I looked them up on this sight and learned I will need to put them in dirt so they can end up going through their cycle to become a moth. We knew they would turn into a moth, just didn’t know how it would look. Feeding them from my hanging potato plant. Jean
August 25th, 2008 at 12:57 pm
Like TW and katrina, I found these worms fasinating. One of my co-workers brough in two from her garden for me to see since I couldn’t believe they actually had a ‘horn’. I doubt they thought I would feel compelled to care for them. But what can I say…I watched then crawl, eat and all the other natural stuff. Soon they were in an old fish tank with plenty of tomato leaves and a few tomatoes to grub on. Within only a few days they were trying to burrow into the sides of the tank. I put them on a pot of dirt (about 5 inches deep) and they are now safely entering the cocoon phase of their lives. I don’t know if I will ever see their moth forms but I hope they have a good rest of their short little lives.
August 23rd, 2008 at 3:09 pm
Last week-end I was over at my Mom’s house, she was complaining that something was eating the leaves on her cherry tomato plant. This plant is in a pot on the patio, the only one left. After a couple of questions I figured it was Hornworms. I swear to God I looked at that plant for a good 10minutes before I saw the 1st one….with the color they have they just blend right in….They also seem to like being on the underside of the leaves. We picked off three of ‘em, big ones too!
Well here it is the following week-end and guess what? One more worm twice as big as the others! You really can’t beat mother natures camoflage!!
August 21st, 2008 at 12:41 pm
This is the second year that we have had these…not in tomato plants but in our ornamental potato vine….they did some damage last year before we figured out they were there. We never noticed the moths. The problem is the vine grows on a pergola that covers our picnic table – absolutely beautiful but we end up with worm poop all over the place every August!!! I’ll be getting the spray soon.
August 21st, 2008 at 8:44 am
Can you still eat the rest of the tomatoes on the plant once you have killed all of the worms?
August 20th, 2008 at 8:52 pm
In the spirit of my late Dad, an excellent tomato gardener, I offer up tomato worms to the birds, as he did. Feeds the wildlife, and hopefully gets them in the habit of coming around looking for a fat, juicy meal. Hope it’s ok if i post my YouTube video of a jay doing just that: http://www.youtube.com/watch?v=2hZjJ_S4Dw0
August 20th, 2008 at 1:18 pm
Why do hornworms have horns? Do they hurt? Also, can they mate with family hornworms? I think they are soooo cool to look at and touch.
August 19th, 2008 at 9:22 am
That blackish circle might not be the work of a tomato worm. I’ve had tomatoes with a problem called blossom-end rot, which is exactly what you described, and as I recall is the result of the soil not being consistently moist – (dry-wet-dry.) I can usually tell when the worms show up because the leaves are stripped from the stem and there’s worm poop on the plant! Good luck!
August 18th, 2008 at 12:01 pm
I WOULD LIKE TO KILL THESE WORMS. WHEN IS THE BEST TIME OF THE DAY TO CATCH THESE WORMS?
August 16th, 2008 at 8:53 pm
I just love to look at the tomato worm, we just cut the stem it is on and let it go in the field across the street. They are so cool and I hope to see some of the moths soon.
August 16th, 2008 at 3:21 pm
okay I have 4 tomato worms in a large pickle jar because my mom was going to kill them. one buried itself. how much dirt should I put in it? it is very big and I was wondering when it will start changing and if the others do the same. what other plants do the eat and how much should I put in the jar?
August 14th, 2008 at 1:36 pm
I can hardley sit here and read these unusual moths called disgusting??? The worms may be ugly… but you must have never seen the adults feeding on the nectar of the flowers it seeks. I have hornworms on my tomatoes every year and though I would like them to eat something else where I can watch them, I do not kill them. I just plant more tomatoes. They have never bothered my peppers or eggplant. When my night flowers start to open in the early evening watching the adults make the rounds is very relaxing. If you plant enough they will not destroy your crop. So sorry if you can grow only one tomato plant….The worms do have a bit of an appetite…Try planting something else they like to eat to draw them from your tomatoes??
August 12th, 2008 at 8:59 pm
oh my, these nasty things have almost dessimated my poor tomato plants, didn’t notice them when picking on Saturday and by Tuesday night.. good grief! first time i’ve had these in a garden. new house , new garden this year, so new dirt.. etc. Is it more likely the larva was in the dirt we used for the new beds (raised beds) or more likely the moth(s) came in from elsewhere and laid the eggs? I’ve been so busy spraying my eggplants for Japanese beetles, i never even considered watching for tomato bugs… GEEZ! ***Great site, by the way***
August 12th, 2008 at 8:41 pm
I have never seen this particular bug on tomato plants before, but they are destroying my plants and the fruit on them. The bug at very first glance loos like a very large Lady bug. On close inspection, it is softer, larger, with the consistency of a tomato worm. Black head, coral red body, black legs and “squishy” BAD BUG
Ann Henning
August 11th, 2008 at 4:09 pm
My daughter just found her first tomato worm and was so excited that she had a catapillar in the garden till I looked at it and told her it was a bad one, then I spotted stems with missing tomatoes. Now she is cursing this worm and afraid to look for more. Thanks for this article it has given us the information we needed to battle this ugly worm.
August 9th, 2008 at 11:23 am
I found one lastnight and another today! My kids thought they were going to turn into butterflys and so I put them in an aquarium with plants. Now that I know what I am dealing with I hate to kill anything but I have some tomato plants and I really want to keep them.
I have seen the pupa in the ground while tilling this spring, I had no idea what it was.
August 7th, 2008 at 11:23 pm
Are they always green? We are having an infestation of these yellow worms that look very much like a tomato worm. If I can figure how to send a picture, I’ll do it! We live in a desert area, we have had one or two tomato plants a year. This seems crazy! Yellow tomato worms! But they are here abundantly!
I grew up in California, and my grandmother always had a garden with tomatoes. I know what a green tomatoe worm looks like! Did we do something here in the desert to set off these yellow worms, by growing tomatoes that aren’t well received here?
Please let me know…
August 7th, 2008 at 11:08 pm
Are they always green? We are having an infestation of these yellow worms that look very much like a tomato worm. If I can figure how to send a picture, I’ll do it! We live in a desert area, we have had one or two tomato plants a year. This seems like crazy yellow tomato worms!
August 7th, 2008 at 9:12 am
I have one tomatoe plant in a pot that I am waiting for the last 20 to mature on. It has had no worms or problems. I looked at this site because in the last month I have noticed 2 of those moths in my back yard. My nephew told me what those moths were. Hummingbird size ? ha! I would say they are Sparrow Size ! One was on the bumper of my car and it took alot of water force in the hose to get it to fly away. Found one on the fence today…water dropped it to the ground where I killed it with wasp spray. Now I have to pick it up later. They are disgusting moths, I get creaped out thinking about them and would hate to ever have one land on me or fly into the house. Totally gross ! Although my tomatoe plant has no worms, concerns, I doubt I will ever grow a tomatoe plant again. Apparently someone in the neighborhood has these worms creating these moths. They are so huge, crows, etc. must think they are birds or be afraid of them too. They serve no good purpose. And the wasp thing… parasites on a worm ? Equally creeps me out. I’ll get my tomatoes at the grocery store thank you! Long Beach, CA.
August 6th, 2008 at 4:50 pm
I just found one in my backyard today. I put it in a shoe box. Did you know that they will turn into these big cool moths. That is why we saved it. The only strange thing is is that we do not have tomatos planted this year and it was on a plant called milkweed. It was eating it. I don’t know why. It is so cool looking. My brother and I love it. We desided that it should be a girl and we named it pumpkin. That is a weird name but it is so cute. The only thing that I want to know is that does the horn thing on it’s tail hurt or harm you if you get poked by it? I would really like to know. The is the second one that we found. We found one 2 years ago. It was not as big. I am so glad that I got to share my story with all of you who look on this website. Bye!!!!
August 2nd, 2008 at 3:20 pm
We have been planting tomatoes in a container for the past several years. Last year, we saw the tomato hornworm near the end of the season with the parasite eggs on it, but didn’t know what it was at the time. This year we have one without the parasite eggs. It started out very small and only ate on two small tomatoes. Now that it is fully grown over the past 3 weeks or so, it has moved on to the tender young tomato leaves. Unless it does significant damage now, I’ll let it stay and hope that the wasp will return so that there is a natural circle of life. If not, I would like to see the pupa and five-spotted hawkmoth complete cycle. I can sacrifice a plant to watch this fascinating process, now that I know what I’m watching. I’ll be better prepared next year to deal with them.
August 2nd, 2008 at 6:14 am
I have been plagued by the tomato horn worm before. This year I thought I was safe because I planted marigolds around the border of my veggie garden. I even planted sweet annie because someone told me it would deter something. So I picked my first red tomato yesterday and there was the telltale blackish circle around the bottom of the fruit. I am so mad I could spit. I want to get rid of these pests before they move onto the rest of my plants. I will try to find these sprays at my local garden shop. Will also try to listen for the clicking noise to find the stinkers. Thanks for the tips.
July 29th, 2008 at 9:33 am
I planted 2 tomato plants, 1 grape and 1 standard size, in pots by my garage. They have grown beautifuly with many tomatoes. A week ago I noticed leaves being eaten and looked for the hook worms, finding 2 and cutting the branchs they were on into a plastic bag. I’m not at a count of 18 worms cut, bagged and disposed of and the plants look terrible……I give up worms!
July 24th, 2008 at 3:31 pm
To Wolflady1: The brown spots on your tomatoes probably indicate a calcium deficiency. Spray the plants and leaves with a calcium supplement spray, and they should get better for this season. Then, for next season, mix calcium (as bonemeal, egg shells, etc..) with your soil prior to planting. You may still need to use the spray midseason, too – we usually do, even after working crushed eggshells into the soil every spring.
July 19th, 2008 at 6:54 pm
I found my first Tomato worm! Were there is one, can I expect to find more? My plants have never been healthier and bam!! I happen to find one while pinching my ends.
Please help.
Distraught wannabe farmer.
July 10th, 2008 at 10:46 pm
This is my first experience with the tomato worm. I planted some of my tomato plants in the new upside down planters. The rest I planted in large patio containers. I did not see any of the moths that have been described. How did my plants get the worms? I used sterilized top soil and gardening soil.
June 13th, 2008 at 9:20 pm
HELP! I have been growing tomatoes for years and this year I put them in pots. The tomatoe plants grew like crazy and is producing a lot of fruit but…there are brown spots at the bottom of the tomatoe. Weird,huh? I know about the marigold trick and it works very well, also, I use ashes from my barbeque to put on my plants. I thinks it chokes out the bugs. It is organic so I have used it for years. But the brown spots at the bottom of the tomatoe. What is a gardner to do?
May 25th, 2008 at 9:54 am
Another way to spot them is to listen. They will make a clicking sound when disturbed, so I shake and feel around on my plants and listen for them. It’s pretty distinctive, so once you get to know the sound it’s easy to hear.
March 24th, 2008 at 9:02 pm
how do i purchase tomato worms if thats possible my beadred drogon loves them
February 19th, 2008 at 8:22 pm
FYI, Marigolds do NOT “stink” to insects, they actually kill insects!
I worked as a chemist in an insecticide manufacturing plant for several years. I became a toxicologist because of my work there and moved on to another area. One of the things I learned there is that marigolds and a few other plants actually generate a natural insecticide that is very effective in killing many insects, breaks down in only a few hours and has a very LOW toxicity to humans and animals. This IS a very effective and safe method of insect pest control AND it tends to discourage many Animal Pests because the plants DO “stink” to them and may cause the plants they want to feed on to taste bad, but that is speculation. Even if Animal Pests DO invade your garden, they are unlikely to be seriously harmed by this because they are most likely to come at night when the marigolds are least active in secreting their natural insecticide AND they would probably have to consume several times their own body mass in garden greenery to get enough natural insecticide to actually be a lethal dose. It’s very unlikely that ANY rabbit or deer is going to be able to do THAT! =^_^=
I would STRONGLY urge anyone who uses the companion planting method to wash their vegetables thoroughly with soapy water before eating any of them! No sense in taking chance with your children or loved ones or yourself. Be SAFE and Sensible. =^_^=
January 30th, 2008 at 12:54 pm
Thanks for a great site.
Since moving to Maine three years ago, I’ve tried to plant tomatoes. Each year the plants (50 of them) have been totally destroyed by these worms. Finally, I know something about them. I finally know that they come from the Five Spotted Hawk Moth. I’m searching for a good picture of this moth.
I’m going to give the tomatoes one more try this year with Green Step Caterpillar Control and Black Light at the ready.
Can the green step be used as a soil treatment?
Thanks for all the great information.
November 26th, 2007 at 10:05 pm
Your site was very helpfull, but man some of the people that have asked questions here must be very stupid.
I think that read about 10 variations of the same question and I am sure that there are more. Look people, search before asking questions because your question might have already been asked.
October 31st, 2007 at 12:12 pm
This has to be one of the most delightful sites – re Hawkmoths and tomato worms that one could ever wander onto. I cut open an heirloom tomato last night and found two green worms in it..and somehow just had to know more, wanted to keep them. seems I am not alone! Question – is it better to try to let them live indoors, cocoon, hatch…but its winter almost now..NYC…so then what? or would it be better to let them go to soil outside on fire escape in a clay pot with soil, and a few tomatoes?
thanks for getting back to me. and thanks for this wonderful site and all the great postings.
Patty
October 24th, 2007 at 3:50 pm
We found some tomatoe worms on our plants and would like to keep them for my grand children to watch… should I put dirt in the bottom of the container and when do they go under ground for winter? How long till they come out? Do they turn a brown color while still feeding? The largest one we have is turning colors? Your site has been very helpful and after 20 years now(second gneration of children) I really know where they come from. ha thanks
October 24th, 2007 at 12:27 am
Hi! We found two today- nowhere close to our tomatoes…actually they were coming from the direction of our honeysuckle. This is where for the last 7 years, during a certain time, we have hummingbird (five spotted hawk) moths. I’ve never once seen a tomatoe worm here and didn’t even know until tonight that the hawk moths were once tomatoe worms. Like I said before the moths are always on our honeysuckle could it be that we have honeysuckle moths???? We would like to keep the two we found. As of right now I have them in a bug box with small cherry tomatoes, tomatoe leaves, and some honeysuckle leaves just in case. I plan to put some dirt in with them tomorrow. Any other suggestions for me?
October 2nd, 2007 at 1:02 am
Oh, I forgot, there is actually an artificial Manduca diet available. You can type Manduca diet in google and several sites will come up. The cheapest I have seen is this one.
http://educationalscience.com/hawkmoths.htm
I haven’t tried it out yet but it is there. 5.00 feeds 17 worms.
I know I’m crazy, but I am planning to rear the worms in my 2nd grade class net year. We will probably plant tomatoes this spring for next years worms though.
October 2nd, 2007 at 12:33 am
For all you kids wanting to rear tomato worms, I found a great site about just that. http://www.manducaproject.com/ It explains everything about them.
My son and I have reared a couple worms each year for the past two years. We feed them trimmings from our tomato plants. Because I can cut a little off each of my plants, the plants are none the worse for wear. Tomato worms, (the ones with the black horns) as well as Tobacco worms (the ones with the red horns) pupate under ground. We let them burro into a large flowerpot and dig them up after a week. I read somewhere they need to be enclosed when they pupate or they may develop deformities.
They take about three weeks to mature and emerge, unless it is to cold. If it is cold, they will over winter under ground
Incase you or your kids have a general love of bugs, there is another site through the university of Arizona that tells you how to rear all sorts of buggy critters. http://insected.arl.arizona.edu/uli.htm
Have fun!
September 30th, 2007 at 1:13 pm
I’m Kali. My daughter found a tobbaco worm and is keeping it. What are the requirments on keeping this magnificent animal?
September 28th, 2007 at 6:21 pm
I teach 2nd grade. One of my students brought in a hornworm to show our class. One student wanted to know what the horn does. I had no idea and told him that I would look it up…so what is the purpose of a horn on the hornworm?
September 27th, 2007 at 6:57 pm
I have had much fun reading your stories about the blessed hornworms better known as the Tomato Worm. I have about 12 tomato plants planted at our back door. They are yielding well but now all of a sudden this pest (tomato worm) have started to eat them, I’ve taught my children to help me with the ridding of them. My children are 14 yrs & 11 yrs old. 1 girl, 1 boy but it is a tidious job so we will be looking for another way to be rid of them. any suggestion helpfull always.
September 26th, 2007 at 4:46 pm
I need to figure out how many legs and how many leg joints it has in each leg?
September 25th, 2007 at 9:26 pm
My name is Jared and I am 9 years old. I have a tomato worm that has shed its skin and is now in its cocoon. It lives in my room in a bug box and I want to know how long it will be before it hatches from its cocoon.
September 22nd, 2007 at 4:16 pm
oops I meant to reply to “Lance”. Mine is definatly a tomato worm
September 22nd, 2007 at 4:15 pm
It is a Cecropia Moth Caterpillar. They look pretty neat!
September 22nd, 2007 at 4:11 pm
*UPDATE* No more worms are coming out of him and he seems alright…
September 22nd, 2007 at 4:08 pm
I just found a horn worm in my garage. I live in Phoenix and it has been over 100 for the last few weeks. I have some tomatoe plants that survived the summer and they don’t have any worms.
If they will eat Willow trees I wonder if I have them in my Acacia. I don’t see any damage but from my experience with these worm if you see damage it may be too late.
September 22nd, 2007 at 1:41 pm
URGENT! I have just found a tomatoe horn worm and I love him. The only problem is there were tons of eggs on him and a few little worms going into him. I took the worms I saw out and the eggs. Every hour I see a few worms come out of him! Why are they coming out? Does this mean he’ll be ok? I hope so! I really like him and have kept them before. He wasnt moving or eating when I first found him but since I have taken a few worms out and some have come out he started to move and eat again, maybe hes alright. Please help me!
Thnx, Hailey and Tomatoe Worm
September 19th, 2007 at 3:38 pm
the spike on the on the worm does not do anything. it just makes it look big and dangerous
September 19th, 2007 at 3:35 pm
no they are not poisonous but it hurts as much as it does when someone
pinches you on saint patricks day.