Hornworm Prevention?

AprilMayJune · January 7, 2013

Apologies if there are 200 threads about this already...I used the search function but didn't find anything that was this exact question. I'm still figuring out the lay of the land here.

So last summer was the first time I'd ever grown a serious amount of tomatoes, aside from the occasional container. Things went pretty well, but naturally this also meant that critters that I hadn't had the pleasure of seeing before all wanted in on my tomatoes and assorted veggies, haha.

We had a small but determined group of hornworms on our plants by mid August (being such a newbie, at first I was like, "oh, cool! Giant caterpillars have come to live in my garden!"...and then I went online and looked them up and was, as you might imagine, disappointed, heh.) Since we only had a few, my husband just grabbed them off and got rid of them, and the damage they did wasn't too bad, but only because I was lucky enough to spot them in time.

I don't want to use any kind of pesticides. Is there any way I can make my plants unattractive to hornworms next year that doesn't involve chemicals? Or do I have to just remain vigilant and kick them out if they crash the party again next year?

ginger2778 · January 7, 2013

Try Bacillus Thuringiensis ( BT), all natural, organic bacterium that gives caterpillars an infection, doesn't harm people. I think you can even buy it at home Depot.
If those caterpillars have a bunch of white eggs on their back, don't kill em. They have parasitized by a wasp that kills them, so it is a beneficial insect's eggs, which we want for them to kill and eat the hornworm!
-Marsha

livinonfaith · January 7, 2013

Also familiarize yourself with the eggs of the hornworm. They are about the size of a pin head and kind of pale green to milky white. They usually are laid singly on the leaves, top or bottom. Once you know what they look like you can pick them off and either squash them or throw them in water to drown them.

Here are some photos that show the egg and also the wasp eggs that were previously mentioned.

http://growingsmallfarms.ces.ncsu.ed...arms-hornworm/

If you happen to miss the egg, you'll eventually see the little brown waste particles that these worms produce. If you see those, you have an idea where to look for the worm which you can then destroy.

Searching for these signs may be enough to keep the damage to a minimum without having to spray. Depends on how many moths you have laying eggs.

Wisbill · January 7, 2013

Agree with Ginger, I have had Hornworm issues in the past and tried BT this season with great results. Do some reading on BT and I think you will be pleased.

AprilMayJune · January 8, 2013

Fantastic -- thanks for the replies, everyone!

Tracydr · January 9, 2013

BT works so well. Do you know what worm poop looks like? When you see that big, black trail of poop pellets, get out the BT and spray.

arivaraci · January 9, 2013

I had horrendous hornworm infestations for the past two years and only got it under control this last year with BT. From advice here on TV : )

coastal bend · January 9, 2013

Spinosad(newer bt) lasted longer than bt for me. I have hornworm and army worm problems every year and the spinosad kept them out longer a lot better control.

jerryinfla · January 9, 2013

I agree with coastal bend -- Spinosad works better and lasts longer for me than Bt

January 7, 2013	#1
AprilMayJune Tomatovillian™ Join Date: Dec 2012 Location: Zone 5 Posts: 63	Hornworm Prevention? Apologies if there are 200 threads about this already...I used the search function but didn't find anything that was this exact question. I'm still figuring out the lay of the land here. So last summer was the first time I'd ever grown a serious amount of tomatoes, aside from the occasional container. Things went pretty well, but naturally this also meant that critters that I hadn't had the pleasure of seeing before all wanted in on my tomatoes and assorted veggies, haha. We had a small but determined group of hornworms on our plants by mid August (being such a newbie, at first I was like, "oh, cool! Giant caterpillars have come to live in my garden!"...and then I went online and looked them up and was, as you might imagine, disappointed, heh.) Since we only had a few, my husband just grabbed them off and got rid of them, and the damage they did wasn't too bad, but only because I was lucky enough to spot them in time. I don't want to use any kind of pesticides. Is there any way I can make my plants unattractive to hornworms next year that doesn't involve chemicals? Or do I have to just remain vigilant and kick them out if they crash the party again next year? Last edited by AprilMayJune; January 7, 2013 at 08:32 AM. Reason: Left out words

January 9, 2013	#9
jerryinfla Tomatovillian™ Join Date: Dec 2011 Location: Central Florida Posts: 377	I agree with coastal bend -- Spinosad works better and lasts longer for me than Bt __________________ Jerry - You only get old if you're lucky.

January 7, 2013	#2
ginger2778 Tomatovillian™ Join Date: Aug 2011 Location: Plantation, Florida zone 10 Posts: 9,283	Try Bacillus Thuringiensis ( BT), all natural, organic bacterium that gives caterpillars an infection, doesn't harm people. I think you can even buy it at home Depot. If those caterpillars have a bunch of white eggs on their back, don't kill em. They have parasitized by a wasp that kills them, so it is a beneficial insect's eggs, which we want for them to kill and eat the hornworm! -Marsha

January 7, 2013	#3
livinonfaith Tomatovillian™ Join Date: Nov 2011 Location: Fuquay-Varina, North Carolina Posts: 1,332	Also familiarize yourself with the eggs of the hornworm. They are about the size of a pin head and kind of pale green to milky white. They usually are laid singly on the leaves, top or bottom. Once you know what they look like you can pick them off and either squash them or throw them in water to drown them. Here are some photos that show the egg and also the wasp eggs that were previously mentioned. http://growingsmallfarms.ces.ncsu.ed...arms-hornworm/ If you happen to miss the egg, you'll eventually see the little brown waste particles that these worms produce. If you see those, you have an idea where to look for the worm which you can then destroy. Searching for these signs may be enough to keep the damage to a minimum without having to spray. Depends on how many moths you have laying eggs.

January 7, 2013	#4
Wisbill Tomatovillian™ Join Date: Nov 2012 Location: wis Posts: 1	Agree with Ginger, I have had Hornworm issues in the past and tried BT this season with great results. Do some reading on BT and I think you will be pleased.

January 8, 2013	#5
AprilMayJune Tomatovillian™ Join Date: Dec 2012 Location: Zone 5 Posts: 63	Fantastic -- thanks for the replies, everyone!

January 9, 2013	#6
Tracydr Tomatovillian™ Join Date: May 2011 Location: Laurinburg, North Carolina, zone 7 Posts: 3,207	BT works so well. Do you know what worm poop looks like? When you see that big, black trail of poop pellets, get out the BT and spray.

January 9, 2013	#7
arivaraci Tomatovillian™ Join Date: Jun 2011 Location: Raleigh, NC Posts: 199	I had horrendous hornworm infestations for the past two years and only got it under control this last year with BT. From advice here on TV : )

January 9, 2013	#8
coastal bend Tomatovillian™ Join Date: Feb 2012 Location: south texas Posts: 114	Spinosad(newer bt) lasted longer than bt for me. I have hornworm and army worm problems every year and the spinosad kept them out longer a lot better control.