Felicia
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I. Hate. Caterpillars!!

I looked out my window yesterday and was admiring how beautiful my almost 5 ft. tall tomato plants looked with all the yellow blossoms and green tomatoes growing. I looked out my window today and one of my tomato plants is now about 3 ft tall and most of the leaves are gone. I went out to see what it was and pulled about 6 Tobacco horn worms off of them. The biggest one I kept for my son and it's over 4" long! Caterpillars already destroyed my broccoli and now I'm not sure if this tomato plant will even survive. Some kind of caterpillar has also been eating my potatoes... I can see the droppings, but can't seem to find the actual things. Besides attracting birds, what else can I do to deter them from eating my poor plants?

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engineeredgarden
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First, you have to find all of the caterpillars and squash them. Then, locate the eggs (which are small, round green spheres) and squash them too. Once they are taken care of, simply spray BT on the plants on a weekly basis, and you'll not have to worry about them again.

EG

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applestar
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Attract Beneficial Insects (see the sticky at top of this forum), though you still have to be vigilant. [url=https://www.helpfulgardener.com/forum/viewtopic.php?p=140425#140425]I'm having trouble[/url] with caterpillars on my cabbages, Brussels sprouts, Cauliflower, Kohlrabi, and Romanesco Broccoflower too :evil:

Did you see [url=https://www.helpfulgardener.com/forum/viewtopic.php?t=18204]this thread[/url]? :twisted:

Toil
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please don't treat Bt like it is harmless. It is not a safe preventive. It kills all kinds of caterpillar. Why not pick them off and focus energy on developing biodiversity? The really mangled plant sounds like a good one for keeping a limited population of hornworm for attraction purposes. Wasps need those puppies alive. Next year you could put a tobacciana catch maybe?

I find it odd, that many "chemical" gardeners use their pesticides more judiciously than "organic" gardeners. How many plants are we talking? I can see Bt for 500 plants, restaurant orders in for a year, and out of options. Were organic gardening the law for hobbyists across the USA, I am almost convinced we would face environmental disaster from all the careless and indiscriminate use of lethal products, neem oil, and soap.

s a home garden preventive? I'll tell you the home gardener's best tool - a calendar! Just set a reminder to go pick the tomato bugs and search for eggs. Everything has a life cycle, and if you understand it you can really kick some butt. Maybe a soft bristle toothbrush will work on the eggs. IDK, get creative!

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engineeredgarden
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Toil - please help me understand your stance on using BT for caterpillars. It is a microbial control method for all leaf chewing caterpillars (which aren't welcome in anyone's garden, as the general consensus dictates)

EG

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rainbowgardener
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Well let me see.... do you like Monarch butterflies? Swallowtails?

Their caterpillars are also killed by the Bt


Here's a study exposing monarchs to pollen of GM maize (which has been modified to have Bt in it)

Researchers dusted GM maize pollen onto the leaves of milkweed, which is commonly found on the edges of corn fields, and is the main source of food for monarch butterflies. Half the monarch butterflies died and the rest grew to only 50% normal size https://www.globalchange.com/monarch.htm

Here's a similar study for swallowtails:

In the laboratory, Bt maize pollen was found to have negative effects on swallowtail butterfly caterpillars (Papilio machaon). Tests used Bt176 maize pollen, which has a high toxin content. The amount of pollen used in the laboratory was based on the amount found in the open on the leaves of food plants such as wild carrot. Depending on the age of the larvae, the LD50 value and the quantity needed for 50 percent of the larvae to die and was between 13 and 36 pollen grains. https://www.gmo-safety.eu/en/safety_science/147.docu.html

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applestar
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Au contraire! My entire back yard is planted as Butterfly Garden with both nectar AND larval food plants, and my kids and I raise Monarch Butterflies every summer from eggs and caterpillars on our own homegrown pesticide -- INCLUDING Bt -- free milkweed leaves. Last year we raised, tagged, and released over 70 Monarchs. :wink:

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engineeredgarden
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ah! See...I don't have a butterfly garden, and didn't even consider what damage can be done to non-destructive butterflies. Thanks.

EG

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soil
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you already said it but birds, and like also said parasitic wasps( if you see a caterpillar that has all these white eggs on the skin leave it alone)

we have birds going through our garden daily. possibly hundreds of them. I saw 1 hornworm last year( that was being eaten by a bird actually) while my neighbor down the road had dozens of them eating his plants alive. he doesn't like the birds even though I tell him that's why he has caterpillar problems.



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