So, our tomato plants are extremely prolific this year, but we'd noticed that a few of the ripening fruit had been munched on a bit. Early last evening, I was summoned to the garden by my boyfriend who had discovered a green caterpillar on one of the branches. A little Google searching and I found it: the dreaded tomato hornworm. We immediately pulled it off and killed it, and then found another one which subsequently met the same fate. Tonight, I killed four more and the last one was in a different spot in the garden.
Now, as squeamish as I am (let's face it, they're nasty and I don't like the clicking noises they make when I miss my first attempt at pulling them off), I'm ok with killing these things individually. However, we're going out of town this weekend and won't be able to be vigilant about removal/destruction. My house sitter is not a gardener, so I don't think we can expect him to be a house sitter, cat feeder, hornworm exterminator.
At this point, I'm thinking our best defense is applying some bacillus thuringiensis. But I have no idea where to find it. I was hoping that some of the organic gardeners here might have an idea where I can find some locally, so that I can send my boyfriend out to get some tomorrow.
Can anyone help?
Home Depot has a really excellent pest control spray that is completely natural (made of different plant oils) and is HIGHLY effective. It comes in a white bottle and has the main ingredients listed on the front of the bottle. I've used it for all garden pests and it works... really well
Dipel Dust (Bacillus thuringiensis, var. kurstaki) was on the shelves at Dennis Gardenland last year.
Pyrethin - also a natural pesticide - mixed with insecticidal soap ( environmentally friendly ) is even more effective.
Interesting, I just noticed one of those suckers on my cactus plant outside the other day. Nice post upso and holland.
The Tomato Hornworm grows into the cool-looking Five-spotted Hawkmoth, which is also called the Five-spotted Sphinx.
According to the Kaufman Filed Guide to Insects of North America, the Tomato Hornworm is similar to the Tobacco Hornworm, and both feed on each other's namesake and on potato plants and other plants as well.
Cool moth or not, I'm not sharing my tomatoes! :)
Thanks for the info, upso and holland. Hopefully, we'll be able to get a handle on this before our plants just keel over and die. I don't know if the one plant is collapsing because of the weight of all the fruit, or due to damage from these critters, but it's definitely not standing as tall as it was. I'm really crossing my fingers that it's the former.
From an organic gardening website:
Organic Control for Tomato Hornworm:
Because the hornworm is so large, the easiest and most effective way to get rid of it is to pick it off of plants as soon as you detect it and either squish it or toss it into a bowl of soapy water. A bad infestation can be treated by applying BT (Bacillus thuringiensis). This is most effective when the larvae are small. If it is a problem year after year, try rototilling the soil either in late fall or in spring before you plant--this will either bury the pupae or destroy them. However, if you see a hornworm covered with white egg sacs, leave it be. The egg sacs are those of a parasitic wasp called the Braconid wasp. Let the eggs hatch, and you'll have an army of wasps ready to defend your garden against all types of pests.
Nice thread. Thanks to all contributors for the information.
We're lucky enough to have the braconid wasp eggs on the property ... it takes a few days for the colony to suck all the life out of the hornworm. I have to watch it getting smaller and thinner every day while I check on the tomato crop. Bizarre, but sort of satisfying.
I wish we had the braconid wasps... I think I would find it sort of satisfying, too! :)
We sprayed last night. I think my boyfriend found one more today, but that's it. I just went out and checked and didn't see any more. I'm hoping this works!! We have so many gorgeous tomatoes, which is just amazing to me since our tomatoes did nothing last year. (This is only our second year of veggie gardening.)
Tomatoes did nothing last year because we had such a cold summer. Remember last July? We had days where the highs were in the mid 60's. Nothing tomato plants like better than hot, humid weather with lots of sunshine.
That's what I thought, but I know people who had better success than we did. I think we may have had two tomatoes and our plants never grew taller than about 18 inches. The plants this year have been nearly six feet high. HUGE difference!
My tomato plants are wilting from the heat. I've been out there several times watering them, but I definitely lost about six plants to high temperatures. Even the peppers are finding it hard to handle the heat.