I think that is what they are called.I get these things every year.What can i do to stop them from coming back?They are eating my leaves and even some tomatoes.Thanks for any help.

Yes, those are tomato hornworms. The simplest way to deal with them is find them and pick them off the plants (I would use tongs). The two worms with the little white cocoons you may want to save though: they have been parasitized by a wasp whose larva eat the worm from the inside out. This is a good thing for hornworm control.

Too many hornworms and some sort of pesticide would be best, but outside my experience. (Someone else will have to chime in.)

Ooooh, excuse me if I get excited! Yes, those are tomato hornworms, but the ones with the white bumps are covered in the cocoons of a parasitoid bracnoid wasp. Here is what happens, from the internet:

>>Rather than killing a hornworm outright, a female parasitoid wasp injects it with eggs and flies away, leaving her brood to hatch inside the live host. The eggs soon release little wasp larvae, which feed on the hornworm until they're ready to pupate.

The larvae form cocoons outside the host's body, and these white projections are easily visible to us. The hornworm is still alive at this point, and may continue walking around, but it has stopped eating. In fact, if you see a hornworm in this predicament, the best way to protect your garden is to just leave it alone.<<

So kill the clean ones, leave the ones with the wasp cocoons on them. Maybe you can get them onto some other plant while the wasps do their work.

As for preventing them, the best you can do is watch for their eggs on your tomato leaves. Little milky globes attached to either the top or underside of the leaf. They are small, but if you get it the habit of watching for them, you'll be surprised how many you spot. Google "hornworm eggs" for images.

Yesterday I found this in my yard: it's the moth that lays the hornworm eggs. She's not your friend, either, but she usually flies at night.

I overlapped Sumire, and she's right, there probably are pesticide controls, but I don't know about them either, sorry. I know someone will know. But if you're getting a lot of the catepillars, perhaps inspecting your plants more regularly would be a good idea. I know they're hard to spot until the plant is near stripped but your eye will learn to spot them if you check frequently.

Here's the underside of the hornworm moth, in case you think you see one:

Hornworms pupate in the soil of your garden all winter. You can get rid of a good percentage of them by turning the soil in your garden a couple times in the fall and again in early spring. Watch for the brown pupas as you turn the soil.

I love that you have a colony of the parasitic wasps - I've never seen them before.

You can use Bt (Bacillus thuringiensis) a bacterial disease of Lepidoptera (butterflies and moths) to control caterpillars. It's safe to use on vegetables and fruits. You can control some of the Sphinx moths by digging up the ones in your yard but they have those wing things which make it easy to get all over the place so you will have a problem with them every year no matter what you do. Hand picking works real well once you figure out what to look for and Bt works really well as long as you use it about once a week (it's been a while since I used it or sold it so check the label to be sure).

With John. BT is the thing to use if you have a large infestation. It's safe for people and pets, and can be used once a week. For occasional hornworms, just remove by hand. And as Daisy said, turning the soil is a good thing to do. If you do use BT, spray only to tomato plants, and avoid spraying on a windy day. This will keep the spray from wandering into other areas where you might have plants that are host plants for butterfly caterpillars.

I wouldn't spray the BT. You already have the wasps.

There is no possible way the BT won't end up where you don't want it - its a living thing.

I wouldn't want to breathe it. Its a living thing.

DaisyI said:I wouldn't spray the BT. You already have the wasps.

There is no possible way the BT won't end up where you don't want it - its a living thing.

I wouldn't want to breathe it. Its a living thing.

DaisyI said:I wouldn't spray the BT. You already have the wasps.

There is no possible way the BT won't end up where you don't want it - its a living thing.

I wouldn't want to breathe it. Its a living thing.

Me too.

BT is a very short lived spray once exposed to air, and common sense, like spraying when the air is still, and wearing a mask will prevent it from traveling. That's why weekly spraying is recommended But the wasp larva are great to have!.

BT is a living organism, but it is harmless to humans, as I stated before. As Carol said, it is short lived. And spraying properly DOES keep it from traveling . Still, if the hornworms are taken care of by the wasps, don't spray. As I have stated before on other threads, sometimes spraying huge infestations of plant pests IS called for. The gardener has to study how bad their infestation is and make that a personal decision as to whether to spray or not.

gardenfish said:BT is a living organism, but it is harmless to humans, as I stated before. As Carol said, it is short lived. And spraying properly DOES keep it from traveling . Still, if the hornworms are taken care of by the wasps, don't spray. As I have stated before on other threads, sometimes spraying huge infestations of plant pests IS called for. The gardener has to study how bad their infestation is and make that a personal decision as to whether to spray or not.

I am generally opposed to spraying, especially on food crops, and I agree with both Daisy and Lynda. I do agree that some major infestations justify controlled, judicious, intelligent spraying. Unfortunately a lot of insecticide users are neither controlled nor judicious nor intelligent In this case, hornworms are big and easy to hand-pick, and the wasps are present--nature is taking her course.

...10 minutes later: Well, I just deleted a three-paragraph rant about the widespread over-use of insecticides. Glad I got THAT off my chest.

Well, yes Zoe, I do agree with the fact that many people just grab the bag of Sevin dust and start throwing it around on everything! I've often "suggested " on many threads that people to please not do that. Normally I NEVER use insecticides, two years back to back for me are more than just unusual; it's frightening. I have read many, many articles about huge local infestations of crop pests last year and this year; why? The real reason is not clear. Many scientists postulate the climate change theory, others blame the many years of overuse of insecticides and the insects resistance to them now, the real reasons for these infestations aren't clear or verified yet.

More than "many"--TOO many, in my opinion.

I tend to lean toward the big picture: Everything's gotten out of whack by overuse of insecticides, herbicides, chemical fertilizers and monoculture, some due to ignorance, some to big corporate greed. Pile climate change on top of that and who knows what will happen? I seem to be feeling a little pessimistic today. Three days of triple digits is wearing me down. When it cools off a bit I need to go out and hunt for...hornworms!

The poor OP Larry is probably wondering how his simple question sparked THIS conversation.

WOW

Thanks everybody that responded
I,m gonna see hornworms in my sleep

I'll bet! I'm sure seeing fruitworms, but not in my sleep but in my nightmares!!!

While the parasitic wasps are infesting many of the caterpillars, and you did get good advice re: not using any sprays or powders or anything of that ilk...

There are benefits to simply planting extra tomato plants and encouraging black nightshade to grow as an alternate host plant for the caterpillars...

At my house, I see songbirds visit the tomato plants and the bean plants... and never see pecking done... Simply isn't necessary to worry about caterpillars at my house!


(Cardinal hunting hornworms on pepper plant)

And... Unlike the above poster who thought that the hawk moth was unwelcome in the garden... I like them!



Can't have enough pollinators!

I've had good luck keeping tomatoes free from tomato hornworms by planting parsley near the tomatoes and letting a few Queen Anne's lace grow in the garden. Years ago I decided to plant parsley under our peach tree instead of the garden and was overrun with hornworms on our tomatoes. After doing a lot of research, I discovered that umbrel-forming plants deter them as a symbiotic relationship develops among parasitic wasps, the umbrels, and the larvae of hornworms. When I moved the parsley back to the garden, the hornworms disappeared and I haven't seen them since.