Controlling Garden Pests Naturally and Organically

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.

horn-worm2_1.jpg hornworm_hawkmoth_1.jpg
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.

Tomato Hornworm Pupa (Cocoon) hornwormegg_1.jpg
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.

hornworm4_1.jpg
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

  1. 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.
  2. 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.
  3. 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!
    hornworm3_1.jpg hornworm5.jpg
    Hornworm with parasite eggs (left)-Joe Boggs, Braconid Wasp (right)-Perdue University
  4. 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.
  5. Companion Planting
    Plant marigolds as a deterrent around or between your tomatoes. Marigolds stink to a lot of different bugs and they avoid them.

511 Responses to “Tomato Horn Worms”

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  1. 300
    janjan Says:

    These nasty critters also like moonflower plants. They will decimate a plant overnight. I keep plastic clothespins nearby to pull them off. Then I feed the fish in my pond with them!

  2. 299
    Cathy Says:

    I need tomato or tobacco horn worms for microscope slide making. I would be willing to pay $25.00 for 100 of them. They could be live, or put into rubbing alcohol as a fixative. You can contact me at triarch@centurytel.net. Thanks.

  3. 298
    Darlene Says:

    The hornworms have also visited my tomato plants…I usually go out in the evening and pick them off and kill them…However, when my son had two pet white rats we used to feed the hornworms to them. They loved them…so rats are good for something aferall…

  4. 297
    Simonne Says:

    I’m the teacher that is raising these beautiful creatures. It happened…from egg to moth. Our first ‘worm’ that went underground hatched earlier this week. He was down and under for about two weeks. He’s been to my home on the weekends and in the air conditioned classroom during the week. (Southern California east of Los Angeles) I watered the dirt every now and then and low and behold…out came this gorgeous gray moth. He/she is so sweet. Strange…our worms love to be petted, head to tail, and now a moth that doesn’t mind it. It is definitely not afraid of my hand. If anyone waters their guys, be careful not to put to much in, like I did this morning. When the flood hits his tunnel, he twitched and twitched. It was kind of cool, but I opened a canal to the area and pourd the extra water out. All this is happening in a large cylindrical butterfly netted cage. Put a small tomato plant in the center and it looks really awesome!

  5. 296
    blackjack89 Says:

    i just picked 10 of them ranging from 1-3 in. and what i usually do,because i dont want to kill a living thing, is throw them over my neighbors fence onto their plants.

  6. 295
    JB Holmes Says:

    Man I have been battling the bastages all summer. Yesterday, 9/29/09 I went out and they wiped out all my tabasco plants. I killed over 30 on 6 plants. I pull them off and throw them into the fence, but make sure not to kill completly. As they still have a little life to them, I feed to all the frogs around. I have one frog that waits every evening for those nasty things. Personally, I hate the worms and they have cost me alot of money and time. I think they would be great fish bait, but I am so pissed when I find them, I nolan ryan them on the fence. Houston,TX

  7. 294
    Janet Says:

    I have tomato plants every year. I pick off the tomato worms and feed them to my box turtles, they love them. This year one of the turtles had eggs so I’m guessing that the worms are good for them.

  8. 293
    Mallie Hyde Says:

    I have horn worms on my angel trumpet every year though I try to take them off and kill them. How can I kill the pupa?

  9. 292
    liz Says:

    A head up for those of you who chose letting parasitic wasps kill off the horned worms for you. These wasps are not discriminate in what they attack. I raise butterflies….and wasp infestations can descimate the caterpillars in a heart beat….and this is sad as well as disgusting when they’re your beloved monarchs or swallowtails etc. Squash those suckers as soon as you see them!!

  10. 291
    Veronica Says:

    In response to Gary and my “experiment” in my fourth grade classroom…
    The hornworm dug himself into the soil in my mason jar. However, he has not moved from the bottom of the jar where I can see him in his red pupa as the picture above shows. I did not know he was supposed to be cold and that a frig might help him emerge as a moth. Do you have any more news of how long he is supposed to be cold?
    Maybe I will put him in the frig overnight on Monday when I return to school.
    It has been a few weeks though with no activity… ?

  11. 290
    Campman612 Says:

    Interesting site, much useful information. I went out to walk the dog a few minutes ago and, while walking past my 8 plants, the tallest of which is about 48″ in height, I noticed that one was completely barren of all foliage and the one next to it was half devoured. I let the dog do his business and then inspected my plants. I saw the worms, walked the dog back inside, retrieved a suitable container, went back out and pried them off where they now repose until I decide whether to try my best Edward ScissorHands routine or just nail them with my heel. Point is, I am aware of their usual fodder but I have never seen a LILAC BUSH listed on any menu for these critters and I am wondering if others have seen them devour other plants in addition to tomatos? One thing I have never seen seen was the horn worm on LILAC plants and yet here in central NH on 9/16/09, I just picked off two of the buggers (pun intended) on a warm September afternoon with no idea where they came from at this time of year. Comments or advice anyone? Thanks.

  12. 289
    Judith H. Says:

    This is the 1st year of trying 2 topsy turvy tomato plants. 1 plant produced 6 approx. 1 inch & smaller tomatoes – the 2nd none!! I just found a a 1 inch hornworm (7 lines and red horn). Theresa on 7/8/09 says this is a tobacco hornworm since the tomato hornworm has 8 lines and black horn. So disgusting!! I’m just going to throw these topsy turvy and terrible plants in the trash!!!

  13. 288
    Gary Baker Says:

    My Wife is a fourth grade teacher and she is wondering what to do with the critters after they bury in the soil and form a chrysalis? She would like for her class to see the worms turn into a moth. We have heard that the chrysalis could be placed in the frig for a while to simulate winter and bring them out to turn into a moth. How long do they need to stay in the fridge?

  14. 287
    Cahri Says:

    Nope Kim, they don’t intentionally. They’re social and not nasty

  15. 286
    Kim Says:

    hey my sister has them in there garden do the wasps sting????

  16. 285
    Susie Says:

    We just lost our entire tomato planting to these guys! We found a dozen plus and hand picked them but unfortunately we missed lots, not having experience them before. Thanks to everyone for sharing so much information, we will now be ready to deal with them another year. We had been spraying with a soap/oil/galic spray, we had a very wet year so guess spray just didn’t get a chance to work.

  17. 284
    Simonne Says:

    I’ve dealt with these guys for years and I take great joy in cutting them in half. This year I have to subdue my killer instincts and raise the little darlings. I teach 2nd grade and about three weeks ago I brought in a catepiller I dug up in my garden. It turned into a dark red/orange,brown crytalis and hatched last weekend. Alas, it was malformed and died. Today, on this wonderful site, I saw all the stages for the tobacco/tomato hornworm moth and there it was! I now have a complete set of the life cycle of this B-52 bomber-sized moth. My cat, Genji San, has gifted me with two beautiful, OMG moths. They keep well in ziplock bags. They’re so big you can see all the details…gross and cool!

  18. 283
    michael Says:

    ipick 5 off and gave to my chickens they love them.i had one thats 5 1/2 long it was so big u could see it ritght off.

  19. 282
    Felycia Says:

    for the last 3 years these worms have been the demise of a certian flower bush. I had noticed the humming bird-sized moth grazing these moon flowers and only recently observed the cooralation. irronically I planted my tomato plant right next to my moon flower (Datura Wrightii, of the nightshade family) and, knowing that marigolds were suposed to deter insects, I surrounded the tomato plant with marigolds. I also pruned the tomato agressivly. wilst I combatted the worms on the leaves of the Datura they seemed much less interested in the tomato. I started pruning every damaged leaf from my flower, picking the worms off and putting them in an aquarium to observe so as to appease my curiosity.

    I would much rather utilize this prolific pest to feed something than just kill them. I am searching to discover if they might make appropriate food for an eastern box turtle, since they are much easier to catch than crickets. The nightshade the have been eating is poisonous to humans, but the turtles also eat mushrooms that are poisonous to humans so… If anyone has any insight I would appreciate it:)

  20. 281
    Veronica Says:

    I have a hornworm in my fourth grade class. He is in a large mason jar and I give branches of a tomato plant. (The parts that do not produce fruit). I also have put some soil in there as they are supposed to dig to pupate. We will see what happens.

  21. 280
    Jen Says:

    I have a parasitized worm in my garden right now so I’m hoping the wasps really will take care of it. Unfortunately my marigolds haven’t kept out them out. I’ve only seen one, but I’m going to buy worm repellant anyway just to be sure i get the eggs. I don’t usually like chemical sprays, but I have too many tomatoes to loose.

  22. 279
    Susan Says:

    Thanks for all the info. I’ve seen the pupae when digging but didn’t know what they were. Will kill them from now on! My tom. plants are covered with these worms but they haven’t found the eggplant yet. Will try the rhubarb spray today! I were gloves to peel them off [hate the feeling of them grabbing my bare fingers] and throw them in a large bucket. Rain did in about 20 of them the other night.

  23. 278
    Bob and Jodi Says:

    We just pulled 30 or so horned worms off our 8 tomato plants. Some had wasp larve on them but we did not know we should have kept them there. The plants are in bad shape. The worms eat at an unbeleiviable rate.
    To GMac: You and your grandfather are idiots. Kill these pesty worms as fast as you can. The worms left a few half eaten tomatos and stems where leaves used to be. WE HATE THESE DAMN WORMS!!!!!

  24. 277
    Sarah Says:

    I just found one of these huge creatures on our tomato plant and my daughter and I want to make a habitat for it to become a moth. Is there an appropriate method of doing this? We just have it in a mason jar and I picked a couple of small green tomato’s that the worm had already started to devour and put in there with it. By morning the tomato’s were almost gone and the jar is in need of a thorough washing. Just wondering if I should put it in a larger container and keep feeding it tomato’s or if there is something else I can give it. (I’m selfish when it comes to my fruit, don’t want to share with the worms!)

  25. 276
    rita harris Says:

    I just found these things on my patio tomato plants. They are huge! However, close up, they are very interresting. I built an animal habitat for them and took them to my classroom (1st grade teacher). My class will be excited to learn that they will become a Hawkmoth. Some are already making their cocoon. What a teachable moment! BTW – I no longer have my patio tomatoes :(

  26. 275
    Stacie Says:

    We have had an abundance of hornworms this year. We’ve also discovered that our ducks find them to be a tasty treat!!

  27. 274
    Wayne Says:

    Kathy you have the right idea there. To be ecological, this would be best, yet for those who dont want to take that time, my eco insecticide will work, but i stress that people should do some research into friendly bugs to make your garden an ecological planet of its own… It is amazing the things you see in your garden that you wouldn’t normally take notice of.. Companion planting also helps to a degree, atm we r in winter… but come spring, I am going to plant my tomatoes amongst pyrethrum plants… I found this can have beneficial effects for both plant and friendly insects… cheers

    PS Linda…. Catfish…. yuk… lol… But I suppose its no different to tuna…. I’d like a catfish as a pet…

  28. 273
    Kathy Says:

    The reason you would want to keep them alive is to help support the wasps population that lay their eggs on them. The more wasps, the less we will see of the horn worms. What I do is pick them off the plant and put them in a bucket, which they can’t climb out of. Then I feed them tomatoe leave clippings. After a few days, they are covered with larvae from the wasps. These are very tiny wasps that you never really notice. They don’t bite or sting people as far as I know.

  29. 272
    eileen Says:

    After the decimation of my garden, I discovered hornworms. I picked them off and now my 6 year old is enjoying them as pets.

  30. 271
    Linda L. Says:

    I pick off the tomato worms by hand and put them in a small container with a few tomato leaves then give them to a friend who uses them for catfish bait. They work very well and the friend rewards me with a catfish dinner!

  31. 270
    Wayne Says:

    Yes this is true they are a problem… With the use of Pyrethrum or an insecticide (Some Rhubarb leaves in a bucket of water left overnight, strain, and bottle the water and you have a natural insecticide, pls use gloves for this as it is poisonous).. Spray when plants are young, and b4 flowering and then as fruit appears… This should be effective to control most if not all, bugs on tomato plants and indeed nearly all plants… Good luck as post here of the results if you please.. I would be interested to see how well it works…

  32. 269
    AEmmott Says:

    Thanks for this article for helping me identify the eggs! Now I can prevent some future damage. We have lots of tomatoes and eggplants and these things get all over both. They seem to go through an eggplant faster than a tomato plant. These things do not go quietly and are hard to cleanly remove, even if you manage to kill them while they are still on a branch. Their feet grip tight, even after death. Easiest way, I’ve learned, is to just peel them off with a trowel, them smash them.

  33. 268
    Melissa Says:

    Hi, I just found some green hornworms, with red horns and white lines, they devoured the top of my tomoto plants and some tomotoes. I don’t want to kill them but they make my stomach turn. I live where there are plenty of lots around me, can I just put them in the woods? they are really big so they may be ready to pupate, i just think they are really gross.

  34. 267
    Tina Says:

    I don’t know which “bug” is worst. I planted Chrysanthemum for flower show and the aphids would make me sick to see them every where. Now I see the green worms on my tomato plants. This is the first time ever I saw these creatures on my tomato plants. I use the chopsticks to pick them. So far I don’t have this problem with my topsy turvy one. To catch these worms, you have to go out at night when the sun goes down with a flashlight. I don’t like to kill anything that are alive so I came up with a solution…spray the whole entire plant (adjust the nozzle) for about a minute or so. It will shake loose the poops and the eggs. So far it works out for me and I don’t see much of those worms.

  35. 266
    Holygrunt Says:

    I found two large hornworms on my tomato plant after waiting a month past when I expected fruiting. I got one dinky tomato so far and they destroyed the next one in line. I found another smaller one had chewed off nearly three more branches of my other tomato plant only 3 days later. After reading the above, I wish I would have kept that one because it had the Wasp larva in it. I thought it was carrying it’s own larva or something, so I torched it. I found that even with Butane, they have a high heat tollerance before they start burning. I take the destruction of my plants very seriously.

  36. 265
    MikeC Says:

    I have 2 tomato plants growing in topsy turvys. It is the first time I have used them and the absolute last time, they are going into the trash after the growing season. The results have been poor compared to traditional ground planting and I have 1 hornworm that has completely destroyed 1 plant in 2 days. I have grown tomatoes for many years and this is the worse I have seen.

  37. 264
    DebbieM Says:

    I too just recently found several hornworms on both my tomato plants. All I did was cut the branches off w/ the hornworms on them. I have an apartment balcony, and my one tomato plant is also in a topsy turvy. My other tomato plant sits next to a pot w/ chili peppers and jalapenos. Could it be that they did not bother the chili’s because of the jalepenos? Or should I be concerned. I have not seen any eaten leaves, not even spots on leaves yet. I also have 2 huge basil plants. I’ve seen some holes in a few of the leaves, but no yellowing or chewed up leaves like the tomato plants. Question… Why would you want to keep them? Didn’t want to be a caterpillar killer, but spent a lot of time trying to grow these tomato plants.

  38. 263
    B Says:

    What does a baby one look like? I found something in the garden, I guess caterpillar or worm like on a tomato it was cover by a white thing. I don’t think it was a tomato worm, but my mom did and said to get rid of it…was it a caterpillar or a horn worm? so confused…

  39. 262
    Chanda Says:

    To Al Black: The good news is that they’re almost big enough to pupate, after which they will no longer require food. (When you see a dark, pulsing line along the center of their backs, that means they’re ready to pupate.) Until then, you can continue to feed them tomato or pepper leaves, or I’ve been able to feed them jimpson weed leaves, if you’re in an area where that grows. Sometimes the big ones are a little difficult to switch from one food source to another – the little ones have an easier time with the transition – so they may refuse anything other than pepper leaves, if that is what they’re used to.

  40. 261
    GMac Says:

    To those of you trying to get rid of the worms… look for their droppings 1/8″+ diameter and the stripped limbs. Just thump the criters off if you have to – and step on them or leave them in the sun…

    To those of you who want to keep them, put them in a large jar with 4+ inches of soft soil on the bottom. Prune your tomatoes a bit or other tender leafy garden plants and put them in the jar (allow for oxygen to get into the jar) and the criters will know what to do next.

  41. 260
    Theresa Says:

    Many of you may have tobacco hornworms instead of tomato, they are basically the same except that tobacco hornworms have a red horn and 7 white lines, while tomato have a black horn and 8 lines.

  42. 259
    Theresa Says:

    Handpicking is the best method as they are hard to kill in other ways without hurting your plants..hard to find before damage occurs (without good eyes), but if you really are thorough you can find the damage (even if it’s small) and follow it to the hornworm..look for the poop too, when they’re tiny it looks like someone sprinkled pepper on the leaves..the telltale horn is a good way to spot them.

  43. 258
    Theresa Says:

    To Leslie, Dill is a good trap plant for hornworms.

  44. 257
    Theresa Says:

    To Al Black, they do prefer tomato foliage, however I do believe that you can buy a kit online that comes with food for them as well; check some other sites, they will tell you exactly what you need and what to look for. I’ve been keeping them every year for the past 4 or so and they will eat much and get bigger..you will have to put them in something with enough dirt in the bottom for them to burrow down and pupate..more details online..google!

  45. 256
    Debbie Says:

    They like bell pepper plants also. I just killed several of the nasty green monsters after they ate almost my entire tomato plant. It was in a topsy turvy. I have three others in the ground. I have never had this happen before and it sucks.

  46. 255
    Texas Jaybird Says:

    I found two hornworms on my Fresno Chili Pepper plant this morning. Yester, the plant was gorgeous and covered in leaves and peppers. Overnight, they ate 75 to 85 percent of my foliage and about 10 peppers. Ironically, they didn’t touch my nearby tomato plants.

  47. 254
    Al Black Says:

    There they were. Two of them, big and fat and green and 3″long stripping my pepper plants leaves. Then I thought of this borgeous, 4″ moth here abouts lately. Now, on my desk clendar where Mildred and Frank are still clutching my pepper stem, comes a 3/16″ little roundish Handgrenade shaped poope. Wowee. My wife rushed, “get rid of them.” No way. But what can I feed them other than the veggie garden delights they consume like a vacuum cleaner? Please help. I have them in a glass jar until “you” reply. Best. A Black. Please hurry!

  48. 253
    Crystal Says:

    For Marie…You can keep them. They do eat other things besides tomato plants but they do prefer them. Let her pick them off and put them in a glass jar or plastic container. Put dirt in the bottom and they will need to be kept fed with fresh tomato leaves. This way she can see them grow and observe the cocoon stage and the hatching. It’s pretty cool for a child to see this. I did this as a child and loved it. My Dad just sent my husband home last night with some for me to do the same with the kids. Have fun with them.

  49. 252
    randy Says:

    i use ivory soap and water in a spray bottle ,about a teaspon per quart ,it kills all soft body incects,hasnt damaged my plants at all ,and i really spray my tomatoes heavily,kills worms on contact

  50. 251
    Duchess Says:

    WOW… THIS SITE WAS SO HELPFULL… I THANK YOU GUYS FOR BEING HERE… I COULD NOT UNDERSTAND WHAT THE HECK A HORN WORM WAS ON MY TOMATOS…

    THANKS AGAIN,
    DUCHESS

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