Hornworms are kicking my ????

kpatrick925 · August 25, 2011

Well I am starting to just get frustrated. I have been having issues with hornworms and sprayed with BT this past Sunday. Has anyone had any experience with it? I am just wondering if it takes a while for them to die? I found two more yesterday and had to pull 11 tomatoes with worm holes in them. I am including a picture of what I think is a baby hormworm but not sure. I included the baby tomato it put a hole in.

I have pulled 8 worms in the last week and keep seeing worm waste. I just have such a hard time seeing them unless they are hanging out right under my nose and even then I can be looking right at it and all of a sudden it startles me because it is right there. yuk!!

Anyway, my two questions are, is there a delay on when the BT works or should I move to the non organic (I really don't want to lose anymore plants). I went from thinking I would have an over abundance to please let me get one ripe tomato.

And is the worm in the picture a baby hornworm and are they normally yellow when they are babies or is the BT working and it is getting ready to die? I removed it from the plant but am curious.

On the bright side even though the worms have been nawing on my black cherry plant I did eat my first black cherry tomato. Not sure if it was ripe or not but I wasn't going to let the worms get it. It was pretty good, little sweeter than I normally like but my sister really liked it. Appreciate any and all replies.

Kim

saltmarsh · August 25, 2011

What you have in the photo is a cutworm. Result is the same as far as your tomatoes go. The hornworm looks like a hornworm whether it's 1/4" long or 3" long. The hornworm is almost the same color as the tomato vine, making it very hard to see. The easiest way to locate them is to look for worm droppings on the leaves and inspect the stems and leaves directly above the droppings. (poop really does flow downhill) Little droppings - little worm Big droppings - big worm. The cutworm in your picture likes to eat around the tomato where it joins the stem and also eats into the fruit (seems to prefer the side you can't see). I don't spray, I pull them off and step on them. According to this link, the worm stops eating within hours on ingesting the BT.

http://www.bt.ucsd.edu/how_bt_work.html

saltmarsh · August 25, 2011

Try this link: www.bt.ucsd.edu/how_bt_work.html

Keiththibodeaux · August 25, 2011

BT if you are organic, Sevin if you are not. Either way, Horn Worms can be quickly dispatched. BT takes a little longer. Make sure it is fresh and mixed to proper proportions.

b54red · August 25, 2011

I sometimes have to use Sevin when the BT doesn't work very well on some types of worms. I don't know why; but it seems every year I have a spell where there are worms eating the fruit that aren't hornworms and the BT doesn't control them so I resort to the Sevin. Usually just one spraying will take care of the problem. Unlike BT there is a waiting period after using Sevin.

kpatrick925 · August 25, 2011

Quote:

Originally Posted by saltmarsh

What you have in the photo is a cutworm. Result is the same as far as your tomatoes go. The hornworm looks like a hornworm whether it's 1/4" long or 3" long. The hornworm is almost the same color as the tomato vine, making it very hard to see. The easiest way to locate them is to look for worm droppings on the leaves and inspect the stems and leaves directly above the droppings. (poop really does flow downhill) Little droppings - little worm Big droppings - big worm. The cutworm in your picture likes to eat around the tomato where it joins the stem and also eats into the fruit (seems to prefer the side you can't see). I don't spray, I pull them off and step on them. According to this link, the worm stops eating within hours on ingesting the BT.

http://www.bt.ucsd.edu/how_bt_work.html

Saltmarsh, thanks for the identification and link. Interesting reading. So If the BT protein needs to be specific to the worm its possible I have more then one kind (obviously from your identification of the worm in the picture) and the BT I have potentially won't kill it. I've also pulled off an ugly light brown worm that had a scream mask face or back end. Didn't look at it that closely as it just freaked me out.

kpatrick925 · August 25, 2011

Quote:

Originally Posted by Keiththibodeaux

BT if you are organic, Sevin if you are not. Either way, Horn Worms can be quickly dispatched. BT takes a little longer. Make sure it is fresh and mixed to proper proportions.

Thanks Keith, although I am trying to be as organic as I can I just don't want to lose my entire crop to worms. They have caused so much damage already. I think I will give the Sevin a try. Have you had any issues with it burning leaves? I always try to follow the directions but have a tendency to spraying heavy. I'm trying to curb that but it is hard when I am in a panic to save my babies.

kpatrick925 · August 25, 2011

Quote:

Originally Posted by b54red

I sometimes have to use Sevin when the BT doesn't work very well on some types of worms. I don't know why; but it seems every year I have a spell where there are worms eating the fruit that aren't hornworms and the BT doesn't control them so I resort to the Sevin. Usually just one spraying will take care of the problem. Unlike BT there is a waiting period after using Sevin.

Thanks B54red. Have you had any issues I should watch out for with the Sevin? I am going to give it a try as I don't want to lose any more plants. I thought I planted more then I could possible need and now I'm worried that I won't even get enough tomatoes to eat much less can.

b54red · August 25, 2011

I've never had any issues with Sevin. I wouldn't spray anything on tomatoes during the heat of the day. I usually spray very early(before bees appear) or very late (after bees are gone from the garden). I prefer to spray very late in the day when it is less likely to affect good bugs.

kpatrick925 · August 25, 2011

Quote:

Originally Posted by b54red

I've never had any issues with Sevin. I wouldn't spray anything on tomatoes during the heat of the day. I usually spray very early(before bees appear) or very late (after bees are gone from the garden). I prefer to spray very late in the day when it is less likely to affect good bugs.

Thanks B54red, I usually do the same, early evening as mornings before work do not work for me.

all I can do to get out of the house

DogsandDirt · October 20, 2011

I've had good luck with spinosad but you still need to spray before or after bees are active. Wet product will hurt them.

clkeiper · November 28, 2011

Kpatrick, This doesn't look like any of the cutworms around here, but the brown worm with ugly face does. They mostly feed at night time and if you do disturb them they fall off the plant and curl up in a "c" shape. They burrow underground during the day and you normally wont see them in the daylight hours. You have to go out with a flashlight to catch them doing their damage. I have had an entire patch infested (first time, last year). if you plant where you had corn and ear damage, also, you may find them more prevalent than where another vegetable was planted last season.

If you find a hornworm that has little cocoons all over its back, leave it. those are tachnid wasp casings and they are beneficial insects for the garden. The horn worms quit feeding as soon as the wasp lays her eggs on the worm. The hornworm will not move after this, either. Then it dies as soon as the wasps hatch out.

kpatrick925 · November 28, 2011

Thanks Carolyn, they really did a number on my plants. I didn't see any of the hornworms with the cocoons on their backs but am now on the look out for next year.

gourmetgardener · December 3, 2011

Bt products work pretty good usually - another product that works pretty good as well is entrust - an organic product from bacteria. In any case, it is important that all surfaces of the plant are throughly covered. Another product with very low toxicity to mammals is called ambush (a synthetic derivative of chrysanthemums) - it has the added effect of having rapid knockdown, usually minutes. Sevin has the problem of resistance with many insects nowadays, and it can leave a little bit of a white residue. For commercial growers, Matador (similar to Ambush) works the best, as it has virtually no risk of poisoning to mammals in small amounts unless deliberately ingested, works on a broad spectrum of insects, and does not leave behind an unattractive residue.

August 25, 2011	#2
saltmarsh Tomatovillian™ Join Date: Apr 2010 Location: 2 miles south of Yoknapatawpha Zone 7b Posts: 662	What you have in the photo is a cutworm. Result is the same as far as your tomatoes go. The hornworm looks like a hornworm whether it's 1/4" long or 3" long. The hornworm is almost the same color as the tomato vine, making it very hard to see. The easiest way to locate them is to look for worm droppings on the leaves and inspect the stems and leaves directly above the droppings. (poop really does flow downhill) Little droppings - little worm Big droppings - big worm. The cutworm in your picture likes to eat around the tomato where it joins the stem and also eats into the fruit (seems to prefer the side you can't see). I don't spray, I pull them off and step on them. According to this link, the worm stops eating within hours on ingesting the BT. http://www.bt.ucsd.edu/how_bt_work.html Last edited by saltmarsh; August 25, 2011 at 02:10 AM. Reason: first link didn't work

August 25, 2011	#4
Keiththibodeaux Tomatovillian™ Join Date: Jun 2011 Location: Louisiana Posts: 587	BT if you are organic, Sevin if you are not. Either way, Horn Worms can be quickly dispatched. BT takes a little longer. Make sure it is fresh and mixed to proper proportions. Last edited by Keiththibodeaux; August 25, 2011 at 02:29 AM.

November 28, 2011	#12
clkeiper Tomatovillian™ Join Date: Nov 2011 Location: ohio Posts: 4,350	Kpatrick, This doesn't look like any of the cutworms around here, but the brown worm with ugly face does. They mostly feed at night time and if you do disturb them they fall off the plant and curl up in a "c" shape. They burrow underground during the day and you normally wont see them in the daylight hours. You have to go out with a flashlight to catch them doing their damage. I have had an entire patch infested (first time, last year). if you plant where you had corn and ear damage, also, you may find them more prevalent than where another vegetable was planted last season. If you find a hornworm that has little cocoons all over its back, leave it. those are tachnid wasp casings and they are beneficial insects for the garden. The horn worms quit feeding as soon as the wasp lays her eggs on the worm. The hornworm will not move after this, either. Then it dies as soon as the wasps hatch out. __________________ carolyn k

August 25, 2011	#5
b54red Tomatovillian™ Join Date: Sep 2009 Location: Alabama Posts: 7,068	I sometimes have to use Sevin when the BT doesn't work very well on some types of worms. I don't know why; but it seems every year I have a spell where there are worms eating the fruit that aren't hornworms and the BT doesn't control them so I resort to the Sevin. Usually just one spraying will take care of the problem. Unlike BT there is a waiting period after using Sevin.

October 20, 2011	#11
DogsandDirt Tomatovillian™ Join Date: May 2011 Location: Dallas/FortWorth, TX Posts: 116	I've had good luck with spinosad but you still need to spray before or after bees are active. Wet product will hurt them.

November 28, 2011	#13
kpatrick925 Tomatovillian™ Join Date: Mar 2011 Location: San Lorenzo, CA Posts: 112	Thanks Carolyn, they really did a number on my plants. I didn't see any of the hornworms with the cocoons on their backs but am now on the look out for next year.

December 3, 2011	#14
gourmetgardener Tomatovillian™ Join Date: Feb 2011 Location: Canada (Zone 6b) Posts: 119	Bt products work pretty good usually - another product that works pretty good as well is entrust - an organic product from bacteria. In any case, it is important that all surfaces of the plant are throughly covered. Another product with very low toxicity to mammals is called ambush (a synthetic derivative of chrysanthemums) - it has the added effect of having rapid knockdown, usually minutes. Sevin has the problem of resistance with many insects nowadays, and it can leave a little bit of a white residue. For commercial growers, Matador (similar to Ambush) works the best, as it has virtually no risk of poisoning to mammals in small amounts unless deliberately ingested, works on a broad spectrum of insects, and does not leave behind an unattractive residue.