-
Brandymae1
- Newly Registered
- Posts: 9
- Joined: Tue Oct 28, 2014 6:04 pm
- Location: South florida
Tomato hornworms, leaf miners, cabbage worm & more!
I just moved into a new house, planted a nice garden with my two little girls and with in 3 weeks the pests are out of control! Ive planted marigolds, tomatoes, iceberg lettuce, basil and just put in a couple pumpkins. We also have a few avocado trees in the yard if that makes a difference. The 1st to come were the tomato hornworms, I sprayed natria on them which didnt seem to make a difference so I bought neem oil and sprayed that. It seemed to be helping until today. I checked my lettuce and found what I'm guessing were leaf miners eating in between some of the leaves. Then, when I checked my basil there was a long green caterpillar eating it! I looked it up and it was a cabbage worm for sure. How do I get rid of these things? Id like to stay organic because we will be eating this stuff (unless the bugs eat it all first) I just re sprayed with neem oil. I'm in S. florida of that makes a difference. Thanks for any help or suggestions!
-
rainbowgardener
- Super Green Thumb
- Posts: 25279
- Joined: Sun Feb 15, 2009 6:04 pm
- Location: TN/GA 7b
If you only have a few tomato plants, the best short term solution for hornworms is just hand picking them. You have to look very closely, because they are well camouflaged, but once you spot them, they just sit there.
Longer term solution is to be sure you grow in your garden. some of the flowering plants that have nectar in tiny florets. This includes anything in the carrot family (carrots, parsley, dill, etc) as long as they are left to flower, but also sweet alyssum, mustard, white clover, yarrow, chamomile, buckwheat, catnip, angelica, fleabane and others. The reason is that these flowers are very attractive to a number of beneficial insects, including a tiny non-stinging parasitic wasp called braconid wasp. These wasps lay their eggs inside the hornworm. When the larvae hatch out, they eat the hornworm from the inside out (I know, eeeuuw, but you really don't want those hornworms, do you). When they are ready for metamorphosis, they emerge from the hornworm and form little white cocoons all over it.
If you ever see a hornworm looking like this:
https://www.extension.umn.edu/garden/ins ... 4-1-lg.jpg
leave it alone. Those cocoons will hatch out into adult braconids to get ready to start the next generation. It really does work. I grow a lot of that kind of stuff and I almost never see a hornworm that isn't parasitized.
You are sure what was in your lettuce was leaf miners, not cabbage worms or cabbage loopers? Leaf miners are inside the leaves and you never see them, just the trails they leave, pale beige or whitish tracks where they have eaten the leaf tissue away:
https://upload.wikimedia.org/wikipedia/c ... tomato.jpg
If you could see the worm, it wasn't leaf miner. Here's a couple articles about organic cabbage worm control.
https://www.motherearthnews.com/organic- ... z3HVPi64WQ
https://www.planetnatural.com/pest-probl ... m-control/
I think it really helps to have bird feeders, bird baths, etc around your garden, because there are a number of birds that like to eat them.
Longer term solution is to be sure you grow in your garden. some of the flowering plants that have nectar in tiny florets. This includes anything in the carrot family (carrots, parsley, dill, etc) as long as they are left to flower, but also sweet alyssum, mustard, white clover, yarrow, chamomile, buckwheat, catnip, angelica, fleabane and others. The reason is that these flowers are very attractive to a number of beneficial insects, including a tiny non-stinging parasitic wasp called braconid wasp. These wasps lay their eggs inside the hornworm. When the larvae hatch out, they eat the hornworm from the inside out (I know, eeeuuw, but you really don't want those hornworms, do you). When they are ready for metamorphosis, they emerge from the hornworm and form little white cocoons all over it.
If you ever see a hornworm looking like this:
https://www.extension.umn.edu/garden/ins ... 4-1-lg.jpg
leave it alone. Those cocoons will hatch out into adult braconids to get ready to start the next generation. It really does work. I grow a lot of that kind of stuff and I almost never see a hornworm that isn't parasitized.
You are sure what was in your lettuce was leaf miners, not cabbage worms or cabbage loopers? Leaf miners are inside the leaves and you never see them, just the trails they leave, pale beige or whitish tracks where they have eaten the leaf tissue away:
https://upload.wikimedia.org/wikipedia/c ... tomato.jpg
If you could see the worm, it wasn't leaf miner. Here's a couple articles about organic cabbage worm control.
https://www.motherearthnews.com/organic- ... z3HVPi64WQ
https://www.planetnatural.com/pest-probl ... m-control/
I think it really helps to have bird feeders, bird baths, etc around your garden, because there are a number of birds that like to eat them.
-
Brandymae1
- Newly Registered
- Posts: 9
- Joined: Tue Oct 28, 2014 6:04 pm
- Location: South florida
The worms I saw in the lettuce were TINY and actually inside the leaf, not on it or below. The only reason I saw them was because I picked ip the dead leaf to see what was going on. I just barely noticed two tiny maggot looking things inside. The thing on the basil was definitely a cabbage worm or one of the similar ones. I did a google search and they looked identical. I havent seen any worms like tha, but have seen a couple of those black wasps stuck inside my patio. Thanks for the heads up, I killed the last one I found =( Ill plant some of those plants this weekend and pick up a bird feeder as well. We have an avocado tree that hangs over the garden that would be a perfect spot for the feeder. Thanks for the tips!
I had tomato hornworm problems last season. I had 15 beautiful plants, various varieties, but they were all indeterminate (meaning vines not bush) . It started slowly, with a worm here and a worm there, and I just yanked em off and killed them manually...but never in my life was I prepared for the carnage that ensued.
One night, they came, while I was sleeping. In that night, they ate every leaf off of every plant I had. They start at the top and work their way down, but there were so many, that by the time I woke up the next morning, I had a bunch of green sticks pointing out of the ground... I had no idea they could do this much damage.
I am looking for an organic answer to this problem. I know what chemicals work, but I am looking for something preventive that I can use. I had been using tobacco compost tea and it worked great for all the little pesky bugs (I just soaked cigarette butts in water and poured it around the perimeter of my garden...yes I might be a redneck).
It wouldn't have surprised me if the hornworms smoked a cigarette after they ate everything. I can't even tell you how many there were, it was shocking...and somewhat repulsive.
Does anyone have an organic preventive measure for this? I don't want them around the plants at all...to the point that I will use chemicals if I can't find a solution. Thanks for your help!
One night, they came, while I was sleeping. In that night, they ate every leaf off of every plant I had. They start at the top and work their way down, but there were so many, that by the time I woke up the next morning, I had a bunch of green sticks pointing out of the ground... I had no idea they could do this much damage.
I am looking for an organic answer to this problem. I know what chemicals work, but I am looking for something preventive that I can use. I had been using tobacco compost tea and it worked great for all the little pesky bugs (I just soaked cigarette butts in water and poured it around the perimeter of my garden...yes I might be a redneck).
It wouldn't have surprised me if the hornworms smoked a cigarette after they ate everything. I can't even tell you how many there were, it was shocking...and somewhat repulsive.
Does anyone have an organic preventive measure for this? I don't want them around the plants at all...to the point that I will use chemicals if I can't find a solution. Thanks for your help!
-
rainbowgardener
- Super Green Thumb
- Posts: 25279
- Joined: Sun Feb 15, 2009 6:04 pm
- Location: TN/GA 7b
So when you came down and discovered all the carnage, were the hornworms still there? Were there hundreds of them? If they weren't still there, how do you know they were the culprit? If it was the hornworms and they did that much damage, there should be tons of big green to dark barrel shaped droppings around. And the worms eat the soft part of the leaves and leave the tough stem at the bottom.
Part of the prevention starts now. If your garden is done for the season, then clear all the garden waste and compost it. Then you need to till or turn your soil. If you are talking about a pretty small plot, you might even want to put the top couple inches of soil through a screen. Does not need to be small mesh. What you are looking for is these:
https://goodlifegarden.ucdavis.edu/blog/ ... 1/06/2.jpg
it is the pupa. It is a couple inches long and will be just under the surface in the area around where your plants were and will over winter in the soil and hatch out next year into the adult moth.
However, even if you could locate and destroy every one of them, that doesn't mean your 2015 garden is safe, because the adult moths are large and are strong fliers, so they can still come in to your garden from elsewhere.
The adult is the sphinx moth (aka hummingbird moth, hawk moth):
https://faculty.ucr.edu/~chappell/INW/ar ... 20moth.jpg
there are a number of different species of them, some more drab colored than this. They can hover like hummingbirds (hence the alternate name). They are especially attracted to pale nightblooming flowers like moonflower and angel trumpet so you don't want to be growing things like this.
Given that you have had a major infestation like this, I think your best choice for next year would be to be ready with the Bt. Bacillus thuringiensis is a bacterium that only infects certain caterpillars and is harmless to everything else. It is sold as Thuricide, Dipel, Bactus, Biological Worm Control, Leptox, SOK, Novabac or Tribacture or other names, but will be labeled as Bt or Btk, the variety that affects caterpillars. Be watching your tomato plants carefully. As soon as you see the first hornworm, spray your plants with Bt. The caterpillars will ingest it when they eat the leaves and it will kill them. It is a disease, not a poison, so it doesn't kill on contact. It will take a couple days to kill the caterpillar, but that is not really a problem, since the first symptom of the infection in the caterpillar is gut paralysis and they stop eating. Bt doesn't affect the eggs, pupae, or adult moths, so you need to spray when the caterpillars are active and eating. It needs to be reapplied after rain.
That is the short term solution. In the long term I believe that having an infestation like that, means that the ecosystem of your garden is out of balance. You need to boost your Garden Patrol - all the beneficial insects and other creatures that eat your hornworms. Keep some bird feeders with nyjer / black thistle seed and bird baths and feed birds year around. Birds that will eat the hornworms include cardinals, downy woodpeckers, baltimore orioles, bluebirds, flycatchers, barn swallows, sparrows, blackbirds, grackles, phoebes. Some lizards and frogs will also eat them. Insects that will prey on the eggs or young caterpillars include praying mantis, ladybugs, green lacewings. These can be ordered on line and released in your garden to start the colony. But they won't stay unless they find conditions they like and they will die if your garden has been sprayed with poisons.
To attract beneficial insects like praying mantis and ladybugs provide them a water source, which would be a shallow dish with little rocks in it. Keep it filled about half way up the rocks. Put a little bit of sugar in the water and they will love it. Provide them some cover. Mantids like to hide in tall grass or in ground cover plants, so leave some shelter spots for them. Grow nectar flowers like cosmos, marigolds and dill, yarrow. And see what was already written in this thread about the braconid wasps. In my garden, the braconids are the most effective parasite of the hornworm and I rarely see a hornworm that hasn't already been parasitized.
Part of the prevention starts now. If your garden is done for the season, then clear all the garden waste and compost it. Then you need to till or turn your soil. If you are talking about a pretty small plot, you might even want to put the top couple inches of soil through a screen. Does not need to be small mesh. What you are looking for is these:
https://goodlifegarden.ucdavis.edu/blog/ ... 1/06/2.jpg
it is the pupa. It is a couple inches long and will be just under the surface in the area around where your plants were and will over winter in the soil and hatch out next year into the adult moth.
However, even if you could locate and destroy every one of them, that doesn't mean your 2015 garden is safe, because the adult moths are large and are strong fliers, so they can still come in to your garden from elsewhere.
The adult is the sphinx moth (aka hummingbird moth, hawk moth):
https://faculty.ucr.edu/~chappell/INW/ar ... 20moth.jpg
there are a number of different species of them, some more drab colored than this. They can hover like hummingbirds (hence the alternate name). They are especially attracted to pale nightblooming flowers like moonflower and angel trumpet so you don't want to be growing things like this.
Given that you have had a major infestation like this, I think your best choice for next year would be to be ready with the Bt. Bacillus thuringiensis is a bacterium that only infects certain caterpillars and is harmless to everything else. It is sold as Thuricide, Dipel, Bactus, Biological Worm Control, Leptox, SOK, Novabac or Tribacture or other names, but will be labeled as Bt or Btk, the variety that affects caterpillars. Be watching your tomato plants carefully. As soon as you see the first hornworm, spray your plants with Bt. The caterpillars will ingest it when they eat the leaves and it will kill them. It is a disease, not a poison, so it doesn't kill on contact. It will take a couple days to kill the caterpillar, but that is not really a problem, since the first symptom of the infection in the caterpillar is gut paralysis and they stop eating. Bt doesn't affect the eggs, pupae, or adult moths, so you need to spray when the caterpillars are active and eating. It needs to be reapplied after rain.
That is the short term solution. In the long term I believe that having an infestation like that, means that the ecosystem of your garden is out of balance. You need to boost your Garden Patrol - all the beneficial insects and other creatures that eat your hornworms. Keep some bird feeders with nyjer / black thistle seed and bird baths and feed birds year around. Birds that will eat the hornworms include cardinals, downy woodpeckers, baltimore orioles, bluebirds, flycatchers, barn swallows, sparrows, blackbirds, grackles, phoebes. Some lizards and frogs will also eat them. Insects that will prey on the eggs or young caterpillars include praying mantis, ladybugs, green lacewings. These can be ordered on line and released in your garden to start the colony. But they won't stay unless they find conditions they like and they will die if your garden has been sprayed with poisons.
To attract beneficial insects like praying mantis and ladybugs provide them a water source, which would be a shallow dish with little rocks in it. Keep it filled about half way up the rocks. Put a little bit of sugar in the water and they will love it. Provide them some cover. Mantids like to hide in tall grass or in ground cover plants, so leave some shelter spots for them. Grow nectar flowers like cosmos, marigolds and dill, yarrow. And see what was already written in this thread about the braconid wasps. In my garden, the braconids are the most effective parasite of the hornworm and I rarely see a hornworm that hasn't already been parasitized.
OMG what an incredible answer, thank you for taking the time to write out such a detailed explanation, that's great! I have never grown anything here at my house before, this was the first season, so I am pretty certain they must have flown in. It's a very rural area, so there are all kinds of things around my house in terms of wildlife.
I am 100% sure it was hornworms, they were still on the plants in the morning, and there were at least 50 of them, if not 100 I was so mad I certainly wasn't counting. None of them had the parasites shown in this thread. They were huge though (not all of them , some where smaller, but still really big and fat)...
I live in a rural area like I said, but not many people grow around here, it's mostly livestock and large fields for grazing herd animals.
I am going down to the feed and seed today and look for the products you mentioned, I also will look into getting the feeders but I Am going to have to order that seed, I doubt he has it. If nothing else, I like birds anyway so that's a win-win!
I just can't imagine how they all showed up at once like that. There were a couple here and there, and my neighbor about 1/2 mile down had some plants and picked a couple of them off, but then all at once, they just ate the whole plant in less than 10 hours, did they hatch from the ground? I don't understand the process, I know that worm builds a cacoon and then turns into a moth. but how does the moth make more, that big 'ol thing in the ground you showed in the picture?
This is a pretty large plot for me, I have horrible back problems so I dread going to turn this soil, but I do really want to have a bunch of tomatoes, because up until that point, they were the best tomatoes I had ever had in my life, I loved them! I would eat em like an apple they were so good... ohh yummy!
I am 100% sure it was hornworms, they were still on the plants in the morning, and there were at least 50 of them, if not 100 I was so mad I certainly wasn't counting. None of them had the parasites shown in this thread. They were huge though (not all of them , some where smaller, but still really big and fat)...
I live in a rural area like I said, but not many people grow around here, it's mostly livestock and large fields for grazing herd animals.
I am going down to the feed and seed today and look for the products you mentioned, I also will look into getting the feeders but I Am going to have to order that seed, I doubt he has it. If nothing else, I like birds anyway so that's a win-win!
I just can't imagine how they all showed up at once like that. There were a couple here and there, and my neighbor about 1/2 mile down had some plants and picked a couple of them off, but then all at once, they just ate the whole plant in less than 10 hours, did they hatch from the ground? I don't understand the process, I know that worm builds a cacoon and then turns into a moth. but how does the moth make more, that big 'ol thing in the ground you showed in the picture?
This is a pretty large plot for me, I have horrible back problems so I dread going to turn this soil, but I do really want to have a bunch of tomatoes, because up until that point, they were the best tomatoes I had ever had in my life, I loved them! I would eat em like an apple they were so good... ohh yummy!
-
rainbowgardener
- Super Green Thumb
- Posts: 25279
- Joined: Sun Feb 15, 2009 6:04 pm
- Location: TN/GA 7b
You are very welcome!
The life cycle goes that the adult moths come in to your garden, fly around, drink nectar, mate, and lay their eggs. So the moths make more by laying eggs.
The eggs, which can be seen with the naked eye if you are looking very closely, are laid on the underside of tomato (or other host) plant leaves:
https://www.uky.edu/Classes/ENT/574/inse ... m/eggs.gif
The egg hatches in to baby hornworms
The hornworm goes through several instars, getting bigger and bigger and more voracious.
Eventually it pupates, becoming the big brown "cocoon" that was pictured, rests, metamorphosizes, and emerges as the moth. Especially in Florida, you probably have two generations of them in a season. So the first adult moth emerges early in the spring, goes through the life cycle and the second generation emerges from pupa mid summer-ish. When it goes through the whole moth to egg to larva to pupa life cycle, that pupa remains in the soil over the winter.
I wouldn't get the Bt now, it doesn't keep that well. Get it in the spring when you first see a hornworm. The nyjer seed for birds is also called thistle seed or black thistle and everyone has it. You can get it at your local big box store.
Not sure why you had the sudden infestation, but they didn't just hatch. The pupa in the ground emerges as the adult moth. The moth lays the eggs, which hatch in to very small pale baby hornworms. The fact that you had different sizes of worms, means that they were eggs that were laid at different times. And the hornworms don't multiply themselves. One hornworm becomes one pupa becomes one moth. The moth does the multiplying because she lays lots of eggs. And the worms don't fly and don't move that fast or cover long distances (the moths can cover long distances, but not the caterpillars). So I'm not sure why all at once you had the infestation. All I can think is that they were there already and some combination of circumstances drew them or favored them getting more active....
The life cycle goes that the adult moths come in to your garden, fly around, drink nectar, mate, and lay their eggs. So the moths make more by laying eggs.
The eggs, which can be seen with the naked eye if you are looking very closely, are laid on the underside of tomato (or other host) plant leaves:
https://www.uky.edu/Classes/ENT/574/inse ... m/eggs.gif
The egg hatches in to baby hornworms
- tobacco_and_tomato_hornworm01.jpg
- tobacco_and_tomato_hornworm01.jpg (52.98 KiB) Viewed 3889 times
Eventually it pupates, becoming the big brown "cocoon" that was pictured, rests, metamorphosizes, and emerges as the moth. Especially in Florida, you probably have two generations of them in a season. So the first adult moth emerges early in the spring, goes through the life cycle and the second generation emerges from pupa mid summer-ish. When it goes through the whole moth to egg to larva to pupa life cycle, that pupa remains in the soil over the winter.
I wouldn't get the Bt now, it doesn't keep that well. Get it in the spring when you first see a hornworm. The nyjer seed for birds is also called thistle seed or black thistle and everyone has it. You can get it at your local big box store.
Not sure why you had the sudden infestation, but they didn't just hatch. The pupa in the ground emerges as the adult moth. The moth lays the eggs, which hatch in to very small pale baby hornworms. The fact that you had different sizes of worms, means that they were eggs that were laid at different times. And the hornworms don't multiply themselves. One hornworm becomes one pupa becomes one moth. The moth does the multiplying because she lays lots of eggs. And the worms don't fly and don't move that fast or cover long distances (the moths can cover long distances, but not the caterpillars). So I'm not sure why all at once you had the infestation. All I can think is that they were there already and some combination of circumstances drew them or favored them getting more active....
-
applestar
- Mod
- Posts: 30543
- Joined: Thu May 01, 2008 7:21 pm
- Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)
The hornworms are very good at hiding....
Subject: Thought you could eat my tomatoes and get away with it, eh?
Subject: Thought you could eat my tomatoes and get away with it, eh?
SP8 wrote:applestar wrote:BTW -- That caterpillar IS in the first photo. Can you spot it?
What do I win?
OK, this has been great. I will wait to get the bt, the store by my house doesn't sell it anyway. I will turn and start incorporating some compost I have for this year as well (I have a lot of compost, we have 13 live oaks on my property), I will hunt for the pupae. It's a shame really because the moth is pretty. I guess I just wasn't watching as closely as I should have been, they do hide really well, I mean...REALLY well, I had so many plants going, that I would look at the tops, and look for the missing leaves, and that's how I was finding them in the past. I don't know why they go to the highest point, but it seems that they do, they seem to eat from the top down.
Again thanks so much, I have this bookmarked now for all this wonderful information. What other place can you get an expert answer like that in no time flat, my hat's off to you!
Again thanks so much, I have this bookmarked now for all this wonderful information. What other place can you get an expert answer like that in no time flat, my hat's off to you!