Beware the Evil Hornworm!


Guest Post by Jean Greenfield at My Recession Kitchen

Seriously, was Mother Nature
having a bad day when she invented the hornworm?  I’m at a loss, what was she thinking?  What’s the purpose of such an ugly, destructive
creature?  No one seems to know. 

Sure, wasps like to lay their
eggs on the backs of hornworms, to use them as a host.  I could do without  wasps as well.  


This is a
picture of Manduca Sexta, the evil hornworm. 
This is a tobacco hornworm to be exact. 
I’ve always called them tomato hornworms, but I’ve come to find out
there are actually two varieties. This one has seven diagonal stripes and a red
horn, so it’s a tobacco hornworm.  Tomato
hornworms have eight v-shaped markings and a black horn.  They’re cousins.

While I
found this unpleasant creature on my heirloom tomato plant (I’m really not
growing tobacco, I promise) it turns out that the tobacco hornworm likes
tomatoes as much as his cousin.  They can
do a lot of damage, very quickly.  Like


tomato was just starting to turn red, my first ripe tomato….it’s life cut
short. And then there was this…..


Hornworms will, occasionally, attack
eggplants, peppers, and potatoes as well. 
You can discouraged them by planting marigold flowers around your
garden, but the best thing to do is to regularly check your plants.  The hornworms are hard to find because they
blend so well with the greenery, but you’ll know they’re there by the missing
leaves and half eaten tomatoes.  Pick
them off of your plants and dispose of them or feed them to chickens…chickens
think they’re candy. If you have a blacklight, yoGuesthornworm mothu can find them at night since
they glow under the ultraviolet light.  Evil
that glows in the dark!

Eventually, if they live long enough,
the hornworm will go into your soil and come out looking like this….Mothra.  I
don’t want Mothra in my yard either, so I check my tomato plants regularly.

Seriously, what was she thinking??

Jean lives and gardens in San Anselmo, California.


  1. I pick them off my tomatoes and eggplants, too, but I find the sphinx moths to be pretty as they hover among my flowers like night-time hummingbirds.

    Mothra was never so nimble.

  2. Emotional Piffle!!!

    I can only hope that some day we can rise above the “Ewww … Its icky.” mentality.

    This creature is only part of a fascinating life cycle the brings much joy to those of possessing the enlightenment a smidgen of knowledge brings. It is absolutely magic that this green creature turns into a Hummingbird Moth.

    Yes, your monster “Mothra” is actually one of our most fascinating insects (especially to children) to watch as it hovers in front of flowers uncoiling its 3″ long “tongue” to drink nectar.

    If you have never watched this “odd looking butterfly” (a cousin to a Monarch Butterfly) in action, you have truly been robbed of one of nature’s delights.

    I grow an extra tomato plant or two just so that I can show this miracle of nature to the neighborhood kids.

  3. I had two different ones decimate a tomato plant: no leaves, fruit, barely stems. After killing the second hornworm (about 4-5″ long), I just forgot about the poor plant and left it alone in its pot. It’s going into its second Fall now, beginning to put out blooms again, and gave me about 40-50 tomatoes this past Spring. I hope your plant thrives again too.

  4. Ah, it’s good to finally put a name to the monster.

    I found one in my garden amongst the destruction it had caused. I tried feeding it to one of the spiders, but the spider just bounced it out of the web. After that I just tossed it in the trash.

    Thanks for the tip about the UV light. That’s pretty handy.

  5. I found my first-ever hornworm a few weeks ago, efficiently stripping all the leaves from a tomato plant I didn’t even know I had. I think they are quite beautiful, and second the opinion of Dan Mays.

  6. I came home one day last summer to find that the green pepper plants growing in my earth box had TWENTY hornworms on them. I knocked them all into an empty pot and dumped them out in the field. I really try to not be squeamish about this stuff, but twenty of these buggers munching away on the pepper plants was pushing the limits of my tolerance. This year, we’ve had a unusually cool, wet summer and my peppers and tomatoes have struggled. The hornworms have gone elsewhere for their feast as my garden had little to offer them. The bright side of a bad growing season?

  7. For some reason, thank goodness, we do not seem to have too many of those critters. I would gladly trade the Japanese beetles for hornworms. I vividly remember the first one I saw. I was visiting Grandma. I screeched so loud she thought I had injured myself in a major way.

  8. A miracle of nature ? Sure. Fascinating, even. A lean, green eating machine. Do I want it devouring the tomatoes I’ve put so much of my sweat into ? NO. And I don’t have room for an extra tomato for hornworms.

    Quite by accident I did discover that they seem to like birdhouse gourds more than tomatoes, however. I found several there, devouring mostly the young gourds & ignoring the leaves. There was only one on a tomato plant. Any chance I’m onto something and it’s not just a fluke ? I’d gladly plant gourds each year if it helped defend my tomatoes !

  9. I know I am odd here but I don’t think they are ugly! I find them to be quite interesting looking! Now, don’t get me wrong, I don’t want to see them anywhere near my garden, but I enjoy seeing pictures of them!

  10. I’m in the “like the big green monster” club. I plant several tomatoes behind my garage every year just for the horn worms to eat so I can have the Moths in my yard. Neighbors doen’t know. HA! Never did like tomatoes that much anyway…

  11. Probably due to the fact that hornworms are rare in my garden (one last year, none at all this year) I think they are perfectly adorable. If I had twenty, I am sure I could class them as spawn of the devil along with rabbits, deer and ground hogs.

  12. All butterfly lovers hate gardeners!
    Before it was that vivid colored butterfly, it was a worm eating something I did not want it to eat in my garden!

  13. Thanks for this post. I thought the half eaten tomatoes was because of squirrels, but now I will rush home today and check for hornworms.

  14. Before we knew what this was and what it ate, we kept one of these as a pet. Totally enchanted we were. When the wasps hatched we even performed surgery trying to remove them to “save” the thing!

    It does make me wonder though, if its choice of food weren’t so evil, and if it was beneficial friend to the gardener, if it would be considered quite so ugly.
    We’d probably be praising it the way we do the mantis.

  15. WOW…that is one big green creature. I find it sort of pretty, but it were eating my tomatoes that would be another story. Mother Nature and life-cycles aside if I am growing tomatoes that means I want to eat them, not share them with a worm!

  16. I love hornworms! They do damage to my beloved tomatoes, true, but I think they’re so cool.

    I was gardening with a group of 3rd graders once, and they found a hornworm on a tomato plant, which totally derailed the rest of my lesson. We seized the teachable moment – stopped everything to check out the hornworm. All the kids all petted it, except one big, tough kid, who turned out to be a weenie, and one little girl, who loved the ‘worm so much that I think she actually kissed it instead.

  17. Hornworms are like the seventh-inning stretch in baseball – part of the game. In the south where I grew up these things are huge if not sprayed, squashed, or killed. I generally don’t care what they do given that my indeterminate tomato plants are so big (ever seen an Arkansas Traveler plant with good rain about June 15?), we have lots of leaves and even a bunch don’t matter. I have never seen them maul fruit (but I believe you when you say they do). Birds and the squirrels are worse.

    My kids and I take a flashlight with a blacklight bulb out at night in the tomato patch and you can see the hornworms reflect the light back if you are up close to the bush and the leaves aren’t in the way.

  18. I love seeing hornworms on my tomatoe plants. I search every day for them. The reason why I love seeing them is that my chickens absolutely love them. So when I go out to the tomatoe patch, (some 100 plants) the chickens come running because they know they are going to get a free snack.

  19. i found my first-ever hornworm in the backyard–my dog, paco, had found it and was gently picking it up in his mouth then throwing it into the air and trying to make it fly. oddly, i have a totally xeric yard–no tomatoes, peppers, or nicotine growing–only sun-loving/water-thrifty plants. i wonder what he was looking for? paco for a playmate?

  20. I think the hornworm is kind of cool looking- in a horror movie sort of way. In grows like crazy. I grow an ornamental tobacco and pluck the caterpillar off my tomatoes and put them on the tobacco. I think the moth is pretty; they’re all over the butterfly ginger at dawn and dusk right now. Fun to watch.

  21. I actually think they’re cute, but that doesn’t let them off the hook for the damage they do. And their little red cocoons with the moving tail are REALLY creepy.

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