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.
July 18th, 2007 at 10:49 pm
How neat to see how this continues to get comments over several years! I just disovered it, in looking up info on a worm my son just found. If you follow my link, there is a picture on my blog. Is this a horn worm also? Any other info? We’d really like to know!
http://joyinthemorning.clubmom.com/joy_in_the_morning/2007/07/what-is-this-be.html
Loni
AKA – Mama of a Dozen
July 17th, 2007 at 10:04 am
We used to freeze the tomato worms and then use them later as bait on our trotlines (for catfish). These worms and the catalpa tree worm make excellent bait for catfish.
July 16th, 2007 at 9:54 am
I have always had gardens and this is the first year I found one of these nasty things. Where do they come from?
July 14th, 2007 at 12:20 am
My living room is infested with tiny gray moths…..I had bought some organic vegetables including tomatoes, and I had some tomatoes in my garbage, rotting. It seems the moths appeared after I bought these vegetables. Have these moths come from the rotting tomatoes ? Tnx.
July 13th, 2007 at 9:11 pm
Hi! My daughter collected some tomato hornworms and we were just curious about why some of them have red horns and others have blue or black. And are some all brown instead of green? Thanks! Marie
July 11th, 2007 at 4:17 pm
Wrote too soon. Just went out to water the plants and what do I spy? A worm on one of the lower level plants (found one and a half(?)). The larger one was covered with the white larve that I have seen mentioned here. I broke off the short limb that it was attached to and put it in the yard in a sort of shady place. My hope in doing this is that the wasp larve will kill the host worm and will develop and start killing more of the worms for me.
July 11th, 2007 at 12:07 pm
We returned from vacation to find large droppings and a half eaten plant. At first I thought that it had fallen victim to the squirrels that come onto my deck (much to my distain). My husband noticed a large green worm, then another, then another. We removed about 6 in all. I should add that this is in a container, on our deck, with marigolds and a pepper plant in the pot as well. None of those were touched. Oddly enough, the plants that we have in containers on the ground level are just fine. Even the two plant that are planted in a bale of hay and another one in a pot filled with shredded newspaper. This is the first time in 20 years that I have been able to grow tomatos (it has always been the family joke) when I bring home new “victims” to plant.
Will plants come back after being eaten by these worms??
July 10th, 2007 at 9:46 am
I have evidence of tomato worms on my tomato plants. I have already found one and destroyed it. Is there a good time of day to search for them? I would rather not spray for them, What is the best time of day to look for them? Do they have certain habits that i can pattern to catch them?
Thanks Tom
July 7th, 2007 at 8:04 pm
How many worms are there? Why not plant a separate plant for your daughter in a pot that she waters and tends specifically for her tomato worms? Great project, and even a good science project for next year especially with photos and a journal of what she observes. Have Fun!
July 7th, 2007 at 6:43 pm
My daughter caught some tomato worms and wants to keep them but I do not want to have the worms eat my plants. Will they eat anything else besides my tomato plants?
Thank you.
July 6th, 2007 at 12:54 pm
[To Morgan]
Bt (Bacillus thuringiensis) is a naturally-occurring microorganism (soil bacterium) that produces proteins that paralyze the bug’s digestive system. Bt is nontoxic to people, pets and the environment. It also doesn’t kill beneficial insects or their natural enemies (predators and parasites), or beneficial pollinators like butterflies or honeybees.
It’s usually found in garden supply stores as a liquid Bt spray
Hope that helps.
July 5th, 2007 at 8:59 pm
When we had a tarantula (Charlotte) we would hunt for the worms on our neighbors plants to feed to her. Of all the things we fed that spider she seemed to eat those worms with gusto!
This year I’m growing my own plants and caught many of those worms in the egg stage. I hope that I won’t get any this year. Best laid plans and all…
Good Luck
June 26th, 2007 at 10:07 am
I live on the Mojave Desert in California and this has been a very bad year for tomato hornworms. I’ve seen more than usual starting the first week of June. I pick the eggs and small worms daily. It has been a rare day that I haven’t found one or two on six tomato plants and often more. I’ve done this for over 20 years and usually in June will have two heavy times but almost none in between. The moths are more active during full moon time and usually at new moon time there will be no new eggs. I am an organic gardener so I do not use any sprays but have been able to raise very good crops of tomatoes by handpicking the worms.
June 25th, 2007 at 10:09 am
I forgot to mention that I have two sweet basil plants next to one tomato plant that has hardly been attached by the hawkmoth. It seems to work.
June 25th, 2007 at 10:07 am
I reciently planted four 2.25′ x 8′ and 3′ deep container gardens. I live at the edge of the Southern CA desert and I’m overwhelmed with the Hornworm laying eggs. I didn’t know about this moth until visiting your site. I knew it was some type of moth but didn’t know which one. Your photo’s solved my problem. I have a bright light outside that I turned last night and left on. I collected about 80 moths drowning in the dogs water. (large container) Mostly the white or gray moths. And one of the large hawkmoths like in your picture. He was so pretty, I almost let the culprit go.
I’ve lost so many leaves from this bug. I’ve lost whole plants and branches from the squirls also. My poor garden.
Do the white and gray moths lay eggs on the tomato plants also.
June 20th, 2007 at 5:35 pm
I have read in a book that if you plant Borage (its and herb) that it will protect your tomato plants. I’ve planted some will lwt you know if it works…
June 20th, 2007 at 9:03 am
I just found hornworms on my tomato plants, They have eaten the whole plant almost.
What is Bt? and what eles can i put on the plants to keep hornworms away?
Thank you.
June 15th, 2007 at 4:54 pm
We recently got swarmed by the moths,,,,, which must have laid eggs that hatched and demolished an ornamental potato flower vine. How can you keep the moths away in the first place?
May 15th, 2007 at 2:44 pm
Last year was the first year our garden experience tomato hornworms. I just read the sprinkling flour helps eliminate them. Is this true. If the wasps never lay eggs on the worm, then they will eat through the whole tomato crop. Am I correct. Also, do these worms live in the ground or are they larvae from the moth. I don’t want them back this year
Thanks for any info.
Deb
May 14th, 2007 at 10:14 am
I just picked six of the green fellows off my sage bush is that normal…
April 30th, 2007 at 10:41 am
thank you
April 29th, 2007 at 9:19 pm
This information may be helpful for those who are interested
Utah State University Fact Sheet No. 74 November 1999
TOMATO AND TOBACCO
HORNWORMS
These closely related species are similar in appearance, life cycle, host plants, and damage. The tomato hornworm is widely distributed in Utah while the tobacco hornworm is found in Washington County with a possible distribution in the Salt Lake area. The caterpillars can be quite harmful on cultivated host plants while the adults are harmless or beneficial as pollinators. Both species occur throughout most of the United States, often in the same garden. The adult tomato hornworm is known as the five-spotted hawk moth while the tobacco hornworm is called the Carolina Sphinx.
Description and Habits
The adults are large moths, predominately gray or gray-brown with lighter markings. They are commonly referred to as sphinx, hawk, or hummingbird moths. The wingspread of these impressive insects may reach five inches. They emerge from overwintered pupae in the soil in late spring or early summer. The moths are commonly seen at dusk, hovering hummingbird-like over beds of petunias and other flowers with long corollas. Nectar is extracted through their long, coiled, tube-like mouthparts. The hairy, robust abdomen of the tomato hornworm has five yellow spots on each side of the abdomen while tobacco hornworm moths have six. The tomato hornworm moth has two distinct, narrow, dark, zigzag, diagonal lines running across the center of the hindwings. These fine lines are obscured and fused into a single, dark, indistinct stripe in the tobacco hornworm (Carolina Sphinx).
The spherical greenish-yellow eggs are deposited singly on the undersides of host plant leaves. The eggs hatch in approximately one week and larvae begin feeding on foliage. Larvae feed for 3-4 weeks, molt five times, and may reach four inches in length and 1/2 inch in width when full grown. Both species are green with a distinct “horn” on the top of the tail end. The sides of the tomato hornworm are marked with a series of white marks resembling a “v” laying on it’s side and pointing toward the head. The white marks on the sides of the tobacco hornworm form a series of seven diagonal lines. The tip of the tomato hornworm’s horn is black while that of the tobacco hornworm’s is red. Full grown larvae burrow 3-4 inches into the soil and form dark brown, two inch long pupae. A sheath for the mouthparts projects from the head of the pupa and curves downward, resembling the handle of a pitcher. There is one generation per year in northern areas. Larvae consume large amounts of foliage on peppers, tomatoes, eggplant, potatoes, and related solanaceous weeds. Loss of foliage decreases production and increases the amount of sunburned fruit.
Control
If only a few plants are involved, larvae can be removed by hand. Often the characteristic droppings or fecal pellets can be seen before the caterpillar is located. Plants can be protected with common garden insecticidal sprays and dusts registered for the host plants. Various formulations of Bacillus thuringiensis (Bt) kurstaki strain can be used as a safe biological pesticide. Bt is most effective on the smaller (younger) larval stages, the larger the larva the harder it is to kill with Bt or other insecticides.
At times hornworm larvae may be completely covered with small white, elongate, egg shaped objects. These are the cocoons of a small parasitic wasp. Do not destroy or spray these parasitized larvae. The wasps that emerge from the cocoons are harmless to people and may provide some natural control of remaining hornworms.
Jay B Karren Extension Entomologist
April 29th, 2007 at 9:12 pm
go to the following site and see if this the thing that your son got stung by http://images.google.com/images?hl=en&q=scorpion&gbv=2
March 29th, 2007 at 2:22 pm
A friend of mine was working in his garden when he found over a dozen pupate tomato horn moths. He was kind enough to bring one to me in a jar with a good four inches of dirt as a present.
Just today I noticed that his tail end is now protruding from the earth and I am almost 100% sure the moth did this himself (.01% of me wonders if my little sister some how got a hold of the jar and shock it around)
I am looking up information on the habits of these creatures, and I was wondering if anyone here could confirm this is indeed meaning the moth is ready to emerge
Also, could the warmer climate of the jar in my room trick the creature into thinking it is later in the spring, I would hate for him to come out to early
Thank you so much!
Asrai
February 7th, 2007 at 3:44 pm
Where can i buy one of these hornworms???
September 23rd, 2006 at 5:52 pm
I want to keep this Tomato Hornworm but it has a wasp egg on it. Can I take it of? or will the horn worm die.
September 22nd, 2006 at 10:23 pm
hey i know this is pronlably not a horn worm but my son got bit by this black thing with 2 lobster like claws and a stinger on its tail what should ido ? are they harmfull to my kids
September 21st, 2006 at 1:06 am
I was so glad to find this site! Finally, something about these ugly little wormies.
I plucked three out of my garden last, and I’m sure there are more.. I don’t want to kill them, I want to raise them! Is there a way to lure the buggers out?
I’m a reptile owner, and I hear these worms are just as nutritious as silkies (when raised on silkworm chow), but they’re hellova lot easier to care for. I fed them for the week, then today, moved them from the old container to one with 4 inches of soil, and they’ve burrowed under already.
When will they pupate? Should I leave them in the dirt, or can I carefully dig ‘em up and move them into a new container after they’ve completely cocooned? When will they hatch out? I read somewhere that the only way to sex them is by looking at the pupa– Is there an easier way? How many weeks should it take? Should I chill them, or warm them to duplicate seasons? Are all my questions driving you mad yet? Heehee, I think that’s all of them..
September 18th, 2006 at 5:43 pm
My 4 year old found a hornworm and it is his new best friend. I am trying to keep this thing alive but am having trouble coming across a small tomato plant we can keep. It is the end of the season and no one has one. Is there anything else I can set up to keep it till it becomes a moth.
September 7th, 2006 at 6:33 pm
We have about a half doz. in a bug container and they have all cocooned and are buried in soil. They are gross. The cocoons wiggle around. We have prob found 20-30 on our plants in the last few weeks that we have killed. Am going to try the black light thing tonight.
September 7th, 2006 at 6:33 pm
We have about a half doz. in a bug container and they have all cocooned and are buried in soil. They are gross. The cocoons wiggle around. We have prob found 30 pon our plants in the last few weeks that we have killed. Am going to try the black light thing tonight.
September 4th, 2006 at 3:40 pm
It will turn into a moth like hummingbird they may look like a humming bird but they are not.
August 29th, 2006 at 5:07 pm
I’v caught one but i dont wanna make my dad mad by picking the tomato or pepper leaves off his garden.. what els should i feed it?
August 29th, 2006 at 4:18 pm
what will happen if u get stung by the tomato worm’s horn? are they posionous?
August 29th, 2006 at 4:12 pm
I found a worm/caterpillar thats been eating my pepper plant and looks like the picture on top.. can it happen to be a tomato worm?
August 29th, 2006 at 9:20 am
just a litle tid bit for those of you out their who have “interesting children”
the juice/guts of Tomato Horn Worms is very hard to get off of clothing (especially white) so if you see your child squishing them with rocks , thier hands , bike tires etc…. let them know that maybe it’s not a good idea or that play clothes would be a more suitable attire
August 27th, 2006 at 7:40 am
yes only when the eggs hatch will the worm die. the wasp larva would have eaten the worm alive.
August 27th, 2006 at 7:38 am
what plant did you find it on? that plant is what it eats
August 27th, 2006 at 7:34 am
someone on this list said that tomato worms burry themselves in the soil when they turn into a cacoon is this true?
August 27th, 2006 at 7:26 am
My brother caught a tomato worm yesterday. he picked it up and it just sat there.
August 24th, 2006 at 8:24 pm
We live in Arizona and found two in our garage this morning! Have no idea how they got there. There’s not a garden in sight, no one in our neighborhood that we know of has a garden. It’s too hot here to grow tomatoes as far as I know. They look just like the pictures on-line, horn and all! Is it common for them to linger in areas there are no tomatoes?
August 22nd, 2006 at 8:55 pm
The black light works beautifully. If you love your tomato plants invest in the light and an extension cord. I have pulled 18 of the horn worms off of my plants this year (one of them four inches long and about as big around as a good Havana cigar). I just go out after dark with the light and they glow a light flourescent green. With the light you can find them when they are an inch, or less, long. It’s a lot easier to squish them at night too. You can’t see what you are doing.
August 21st, 2006 at 6:01 pm
thanks for the great website. My girls have caught one and we have it in a bug aquarium. Word of advice put a few inches of soil in the bottom as when they are ready to pupate they bury themselves deep into the soil to do so and to over winter.
August 20th, 2006 at 9:03 am
thank you for your web site.its been very helpful and enjoyful reading.bugs r truely amazing critters.bill
August 19th, 2006 at 7:06 am
I was just watering our tomato plants, we have two on our deck. They haven’t looked very good lately. Now I know why. We picked 8 worms off one of our tomato plants. Will we find more? In other words, maybe some more will appear? I won’t go near them now. My husband has to pick what’s left of our “crop” lol. They just sceeve me out.
The kids were wondering what kind of critter they turn into so I went online and found your site. Thank you. Very helpful. The kids don’t want to kill them. They released them in the woods. I hope some other critter will “pig out” on them. They are quite large.
Sue
August 15th, 2006 at 3:40 pm
I really liked your web site on the Horn worm, I t was very helpful, thank you very much.
August 12th, 2006 at 10:09 pm
my tomato worm is turning into a cocoon right now, so I need to know what they eat when they’re moths. unless they don’t eat anything. then I need to know how long they live.
August 11th, 2006 at 9:19 pm
I found a tamato worm in my tomato garden and kept it in a jar. It turned into a cacun. And now in Augest it is hatching, and has been trying to get out for 4 hours now is that normal?
August 11th, 2006 at 7:26 pm
how long do the moths live for and what do they eat?
August 9th, 2006 at 6:40 am
what causes these worms to attack your tomato plants? we planted them with soil from our compose could the compose be infected as well.
please reply thank you.