Organic Pest Control Tomatoes

Hornworms – Why you might need a few in Your Garden?

I received an email the other day from a reader in Richmond, Virginia.  He reported that is garden is doing much better this year even though he got off to a slow start.  He also sent me a great photo he took that morning of a visitor on his tomato plant.

Yes, you’ve probably guessed it — it was a hornworm.

I have a few hornworms from time to time but the Braconid wasp (a beneficial insect) keeps them under control.  So I usually see the worm (paralyzed) with the white cocoons of the wasp’s larvae on their back. In that case — I just leave them so the life cycle of the wasp can be completed.  With those cocoons on his back — the hornworm is paralyzed and no further threat to my tomato plants.

Hornworm is now paralyzed and no threat to the tomato plant. The white grains are larvae of the braconid wasp.

If you’ve had the hornworm on your tomatoes you know they can get as long as your palm and can make fast work of stripping your tomato plants.  That’s usually how I know I have one — when I see a bare stem with no leaves.  Then I look for the hornworm.  He can blend right in with the plant and be hard to spot.

About a week ago, Bill and I were checking the tomatoes and saw the tell-tale stripped branch.  We spotted a huge hornworm —- no cocoons on its back.  Without hesitating I cut the small branch it was on, threw it to the ground,  and stomped it. We found another and did the same.

And then I realized I should not have acted without thinking.

The Braconid wasp lays its eggs inside the hornworm and could have already rendered the hornworm helpless without any visual indication.  I could have discovered that by taking  a twig or a tool and prodding the hornworm.  If he responded then I could have stomped him.  But if he didn’t respond — then I could have left him to complete his role in the life cycle of the visitor you want in your garden — the Braconid wasp.

Even though I try to provide flowers with nectar for beneficial insects — they also need to be able to breed.  So having a hornworm or two is good for keeping the Braconid wasp around.

Fortunately, the next day I found two more hornworms.  One was small and only about an inch long and covered with the white cocoons.  (Made me feel much better.)  I also found another great big one with no cocoons, but he didn’t move at all when I prodded him. So I left him. Haven’t seen any more. I’m satisfied that my tomato plants are safe and that I’ve provided everything this tiny, helpful wasp needs to continue in my garden helping me with pest control.

Now, if I could just get something that would take care of squash bugs.


Related Post:

Discrepancies in id’s –  Hornworms – Eggs or Cocoons


Organic Gardening is easy, effective, efficient and a lot healthier.


All content including photos is copyright by  All Rights Reserved.P

Photo of Hornwom with cocoons is copyrighted by Kristen Leonard.


  • I HATE those darned bugs!! there is a battle in my garden between me and the squash bugs…i WILL overcome!
    another issue, not sure if it’s related to the squash bug or no so that’s why i’m asking…my squash plants are about 90% lovely and green but NO SQUASH. i see tons of blooms but then the next day or so they are all dead.
    i am destroying all the squash bugs and eggs i can find (once a day), so is this some other culprit? please advise and thank you!

  • Beth — you are in good company because many of us know exactly how you feel!

    It is very discouraging to get to the point that the squash are gorgeous, big with lots of bloom — which would have eventually meant a lot of squash — and then have them wilt and die.

    The most common reason for this type of situation is the squash vine borer.

    To see pictures of the moth google “pictures of squash vine borer moth”. It has red on its body and resembles a wasp in looks.

    It lays eggs on the stem — most of the time near where the plant enters the ground but not always. There might be one egg or 3 eggs. The eggs hatch and eat their way inside the plant and continue to eat. Usually the first sign is droopy plants that fail to recover when the sun goes down.

    Ideally — we want to get the larvae out and kill it. Otherwise it will pupate in the soil in what looks like a fiber- like wad. And then when conditions are right another SVB moth will be on the loose.

    I have lost 16 squash plants so far this year! Finally have 4 that might make it through and give me squash. (When I plant squash in the garden — I start more seed — so I’ll have backup if anything like this happens. And I continue with this process until I either get squash — or it’s too late to plant. :))

    I think all of the 16 squash plants I lost were because of the SVB. The plants were small and died quickly, but I would cut the stem open an look for the larvae although they must have been small in those small stems. I never found anything this year other than the opening on 3 plants where they emerged — and I assume went into the soil to pupate. ( I couldn’t find them, but will look again in the fall.)

    In other years, I have cut the stem open on larger plants, removed the huge larvae of the SVB and covered the stem with soil and had the plant go right on producing.

    Many gardeners — myself included — think the squash bugs and the SVB are worst of garden pests and certainly the most trying to deal with.

    Keep on keeping on, Beth! Let me know how you do.

  • Thanks Theresa…I’ll be on the lookout for those and adding them to my MOST WANTED list… 🙂

  • Theresa,

    My husband & I were in the garden early Saturday morning planting a couple of blueberry bushes and concord grape vines when we noticed something had eaten the leaves off of some of my tomato plants.

    We were in a rush to leave & didn’t investigate further at the time.

    As I was reading this post the light bulb went off & I rushed out to check the plants closer. Sure enough I found 2 tomato hornworms! Both were loaded with the cocoons on their backs, so I left them alone.

    I was checking another plant that had signs, but the mosquitos were eating me alive & I had to come in & cover the bites with anti-itch cream & drink some benedryl. Hate those things!!

    Thanks for your post. I can’t wait to show my husband & son when they get home! Woo-Whoo!!


  • Anyone know a natural way to keep annoying flies from tormenting one’s skin by landing on you and tickling you while you are trying to garden?

  • Theresa, what time of day do you have the best luck finding them? I’ve only found one, but lots of stripped plant stems!


  • I never pay much attention to the time of day. I usually have to notice obvious damage before I even look for them. Once I see that – I just keep looking until I find the worm.
    One worm can do an amazing amount of damage in only one day!
    Perhaps, that is what you are seeing – the damage of one worm.

  • I was feeling defeated because I never could find a single one, even though I had several plants with damage.

    I finally offered my grandsons $2 a worm for every one they found & we had a contest! I found one & each of the two youngest found one.

    None had cocoons & they all moved when poked, so we had great fun stomping them.

    I’ll be checking every day to make sure we found them all. I have too many beautiful tomatoes developing to lose them to a hornworm.

    Now I’m back to pulling what looks like millions of baby wheat seedlings from some seedy straw I got this spring. It’s such a mess that I found a different source for my straw.

    Happy Gardening,

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