Beneficial Nemotodes with David Shapiro-Ilan

Learn how beneficial nematodes can control orchard pests including plum curculio and Japanese beetles with entomologist David Shapiro-Ilan at the Southeastern Fruit and Tree Nut Research Laboratory in Byron in this episode of the Orchard People radio show and podcast. 

The host of the Orchard People radio show and podcast is Susan Poizner of the fruit tree care education website www.orchardpeople.com.  

This show goes out LIVE on the last Tuesday of every month at 1.00 pm Eastern Time. After that you can download the podcast. 

To tune in LIVE (and submit your questions to our expert guests!) you can:

1. Tune into RealityRadio101.com during the time of the live show
2. OR watch the livestream on the Orchard People YouTube Channel

Do you want to learn to grow organic fruit trees successfully? Sign up for OrchardPeople.com's free monthly newsletter at https://orchardpeople.com/sign-up/

For premium fruit tree care education visit: https://learn.orchardpeople.com/. 

More Beneficial Nematode Resources here:

• CornellCALS Insect Killing Nematodes Article
• Nematodes as Model Organisms 
• A sustainable grower-based method for entomopathogenic nematode production

Creators & Guests

Host

Susan Poizner

Author, fruit tree educator, and Creator of the award-winning fruit tree care education website OrchardPeople.com.

What is Orchard People?

Learn how to grow and care for fruit trees with fruit tree care educator Susan Poizner of OrchardPeople.com. Discover how to create permaculture plantings, food forests, and forest gardens in both urban and rural settings. Meet experts on all aspects of comprehensive fruit tree care, including pruning, pest and disease prevention, fruit tree grafting and budding, and soil management.

Show host Susan Poizner, creator of the fruit tree education website OrchardPeople.com, is an award-winning author of three fruit tree care books and an ISA Certified Arborist. This podcast is the winner of the 2021 GardenComm Silver Award of Achievement for Broadcast Media: Radio Program Overall. Learn more and access archived episodes at https://podcast.orchardpeople.com/.

Learn more about Susan's books and courses at https://learn.orchardpeople.com/books.

If you grow fruit trees, you know that there are
a lot of pests that attack fruit trees, and they can damage the trees, and they can damage your harvest. I'm thinking about
Japanese beetles, or
plum corculio, or codling moth, or even cherry fruit flies.
There is so much out there to make it hard for us to grow fruit trees.
Now, there are sprays.
And some people use spray, some of them are even organic,
but even organic sprays, they can take a toll on the environment and even on human health.
So wouldn't it be nice if there was another option?
Wouldn't it be nice to have, for each and every one of us, to have a team of helpers who go out there and help us by taking care of the pests for us? And that's what we're going to talk about on the show today.
We're actually going to be talking about fruit tree pest control using beneficial nematodes.
And these are microscopic little critters,
typically they're in the soil. And they can hunt down and kill Insect pests
that will then not be able to damage our fruit trees and our harvest. So that's what we're going to talk about in the show today.
And I'm going to be chatting with David Shapiro Ilan.
Now, he is a research leader and supervisory research entomologist at the USDA Agricultural Research Service. And he's been researching Insect killing nematodes for 30 years,
he's actually developed strains of nematodes that tackle certain types of pests. We're going to talk about that in the show today.
But first, before we dive into the conversation, I would love to hear from you. If you are listening to this show live, I'd love it if you can send in your comments or your questions for David. And for me. so you can send those questions to the email info at orchardpeople. com. That's I N F O at orchardpeople.
com. And remember to include your first name and where you are writing from. So David, welcome to the show today. Thank you.
So, let's start off with a basic question that I need to know. What exactly are nematodes? Are they an insect? Are they an animal? Tell me about them.
So nematodes are simple roundworms.
they are, they have their own phylum,
so they're not the same as earthworms, which are a little more advanced, segmented, and they're not like the flatworms.
So they have their own group, as I say, a phylum, which are the simple roundworms.
And, some of the nematodes are beneficial, such as the insect killing or entomopathogenic nematodes, also known as beneficial nematodes.
And a lot of people in agriculture. Think of nematodes and think about pest nematodes, plant parasitic nematodes that cause damage to crops. And that can be very serious. the nematodes we're talking about are the good guys, and they only attack insects or other arthropods. They won't harm humans or the environment.
most nematodes actually are free living and, they act like, like earthworms. They're breaking down organic matter, feeding on bacteria and things like that. Those would be the most numerous, kind of nematodes. And so in any soil in my backyard, I got nematodes, hopefully, right? Yes. Yeah.
So they're everywhere. Okay. We got a great question from Ruth. Ruth says, Hello, Susan and David. Very interesting topic. Can you actually see nematodes? So, some, you can, the nematodes that we study, these beneficial nematodes, if you look at a glass of water with the nematodes on the free living stage, you'll see like, it might look like a bunch of little dots.
Then under the microscope you'll see them. if you have them in a cup of soil or in your garden, you won't see them there. there are, most of them are tiny, but there is, there are some big nematodes, like there's one kind of nematode that attacks the sperm whale. and it's a gut parasite, which is about, almost 30 feet long.
So you can imagine this giant worm. That's a parasite. That's as big as a python. so some of them are really big, but most of most are really tiny. Wow, okay, so here we've got a comment from Janice. Janice says, are these nematodes just used for fruit trees or can they be used on flowers? And Janice is from New York City.
Yeah, they're not restricted in use to any crop. They're a little bit harder to Get them to work above ground because their natural habitat is soil. But one thing we've done is developed like a gel formulation that protects them above ground so they don't dry out or get hammered by UV radiation that they're susceptible to.
So you can use them, like in flowers, for example, they've been used against thrips, which are important flower pests. I see. Okay. So they can as well. So, all right, we've got the good nematodes. And we've got insect pests. Now let's make the connection because frankly, most insect pests are in my trees. Like, the codling moth are laying their eggs under the skin of the baby fruit of the apples or, cherry fruit flies, whatever.
they're in the air, they're on the tree. Now we're talking about nematodes that are in the soil. So where's, what's the connection? How are the nematodes going to be able to help us with fruit tree pests?
So then these nematodes can be applied using really any standard agricultural equipment, various sprayers, or through irrigation systems.
So, as I say, they're most easily effective when you apply them to soil. So, Many insects, even though they may have an above ground stage, also have a soil stage. There may be pupating in the soil or something like that. So you might apply the nematodes to the soil at that time and kill them. but if they are only, you're trying to kill them in the ground.
In the tree, like some of the borer pests, like a lesser peach tree borer, flathead borers, things like that, you can actually spray where the wounds occur and the nematodes will go in and find the pest and kill them. But again, it's better to use some kind of protective formulation when you're applying them above ground to protect them from UV and desiccation.
Okay, so let's talk about what application looks like. I'm sure that you test this a lot, and I know you tested in orchard environments. So, what, describe to me what it looks like when, growers are applying nematodes to, prevent a certain pest. give me a specific example. so, one of the targets that we, have worked with a lot is peach tree borers, for example, and that attacks, stone fruit trees at the base and girdles down into the roots.
So, so, as I said, you can really use any standard agricultural equipment, boom sprayers, handgun sprayers, backpack sprayers, even a lot of the irrigation equipment and just apply the same way you use. So that people would use chemical insecticides. The only thing different is if you have fine screens.
In your, application system, you'd want to take those out so they don't shred the, nematodes, but otherwise really everything else is the same. So they're really pretty easy to use if you're keeping them in a spray tank for a while. You'd want to make sure that's aerated or at least you have good agitation so that so they're not because they will drown and they're also settle down on the bottom.
So you have to keep them agitated so that they stay in your tank. If you have a backpack spray, it's probably good to like, shake it up every once in a while, just to keep them suspended. Okay, so there they are. They're living, they're swimming around in your sprayer. you're taking out the filter so that you don't smush them up, while you're spraying them with pressure out of the sprayer.
So they're still alive. they're in the soil and they're munching away. And I take it that if I have a specific problem, like peach tree borer, I need a specific nematode for it. So I go out and look for the specific strain of nematodes that will tackle the problem that I have.
So that's fantastic.
then they're in the soil and what do they do? Do they look around? Do they, how do they find the enemy? how do they figure it out? That's one of the really fascinating aspects of the nematodes, I think, is how do they find a host on insect kill? You think about these tiny little nematodes and what's like the ocean of soil?
How do they find that? So that's something we've studied a lot. first, we've found that the nematodes They don't just move randomly in the soil, they move in groups like packs of wolves, trying to find like, the caribou that they're going to take down. And they're going to attack the insect in groups because one little nematode may not do very well against the insect pest because of the immune system of that pest.
So they like to attack in, they move in groups and attack in groups. So they could overcome that insect. Now, sometimes one nematode can kill an insect by itself, but generally, they're going to be much more successful with a group attack. So once they get to that insect, They know that it's an insect to attack, because, for example, they'll know, like, if you put them to a centipede, they're not going in, but you put them in front of a nice, juicy, white grub, they're going to go into that.
And they're going to go in through the, usually through natural openings, the mouth, the anus, or the spiracles, the breathing holes of the insect, and sometimes right through the cuticle or the skin of the insect. Once they're inside, Another really fascinating aspect of their biology is they release a partner.
These nematodes have a symbiont, symbiotic bacteria, that the nematodes and bacteria work together to kill that insect pest. So they evolve together and they have a very close and specific relationship with their symbiotic bacteria, which helps to kill that insect. I'll turn my light back on. Sure. That is absolutely fascinating.
So they travel in packs. They attack. do they eat the creature from the inside, or you said there's the bacteria as well? is this for food? So, the bacteria funny that, called, the friend and foe, food and friend, rather. They'll eat the bacteria. for a while, but then they decide that they're going to be friends again, and they'll take some of the bacteria inside their gut and not digest them and then carry them to the next insect.
The bacteria can survive in the soil by themselves, so they have to be carried. They're dependent on that, and the nematodes to vector them from one insect pest to the next. Wow. Okay. Intense. That's, pretty deadly. It's pretty intense what's going on underground. Okay. We have a question here from Dennis.
I have plum corculio in my Toka, Juanita, Pembina plums, et cetera, and it ruins the fruit. I heard that the curculio hides in the crotch of tree branches. A lot of times they're going to overwinter either in the brush in the orchard or outside the orchard.
Otherwise, they would come in to attack the fruit. Plum curculio is a difficult one because, they, if when they're coming in as an adult, they're attacking the fruit directly. So it's, it's hard to get that kind of broadcast spray to get all the fruit covered with nematodes.
So the more likely scenario that we've worked with in Plum Cucullio is to wait until the fruit drops, once it's infested and then kill the larvae in the soil. So then you're preventing the next generation. Another thing that we've worked on with some collaborators is using trap trees. So you attract.
Pretty most all of the plum curculio one or a few trees, say, per acre and then use those. And when the food drop drops, you clean up all of the lobby with never told. So you're avoiding them entering the orchard, but killing them off. So essentially what you're saying is if they're already in your trees, you've got to wait, you've got to wait, you're not going to help your tree for this year, but you'll be able to help your tree for the following year.
And that's not ideal. Yeah, what Dennis is saying is that he, heard that the curculio hides in the crotch of tree branches over the winter. And he heard that you need to spray these regions like those crotches before the tree blossoms in the spring. Yeah. That would make sense if they're overwintering in those areas, you can get them, if they're overwintering in the brush, and within the orchard, you should be able to get them then as well.
The nematodes you'll want to apply, say, between, At best, 18 to 28 Celsius, roughly in that range. If it's too cold, they won't be active and it's really getting too hot. You'll lose activity. Some species of nematodes will be more cold tolerant. Others will be more heat tolerant, so it depends which one you're using.
Okay, and I know you can't recommend a specific brand or type. so Dennis needs to find, a brand of nematodes that tackles the plum curculio. And we, you said the application will be after the fruit falls. But again, his question about, spraying the crotches of tree branches after the winter and the spring, so you have to wait for the right temperature, but would it be okay to spray the nematodes right onto those crotches of the tree branches?
I think so. I have to say from what I've read, the crotches in the tree are not necessarily the primary place, but it may vary where they're overwintering. So if you know that's where they are, then yeah, go after them there. But if you know they're in the brush at the base of the tree, then you'd probably, you'd want to go there.
I can say like for Plum Cucullio, The species of nematodes that we see work the best, the most common one is Stannanema corporecapsi, and then Stannanema reabraba, which is also very effective against that pest. Oh, that's good to know. So we can identify which strains are important for that particular one.
We've got an email from Jamie and I, it's a really important question.
So Jamie asks, do nematodes live all year round? Jamie's listening from Niagara Falls, Ontario, and I feel like it's an important question because you're applying these nematodes, you're paying money for whatever the product is, the biocontrol product, and are they going to be helping you out next year?
Or is this, they're only helping you out for the next two weeks? How long did they last? It's a really good question, that many farmers want to know, can I apply it once and have them work for several years. the general thinking has been that you will have to apply them every year. Now, they will let, they do live.
they can live several years and they'll recycle and, in the pests that are in the ground, they'll reproduce. But usually the level of population of nematodes you have the following year is not at the level that you need for pest control. However, there has been recent research on finding more persistent strains Ways to make them persist better.
So, for example, just recently, one of our postdocs, Kyle Slusher, was working in a pecan orchard and applied nematodes one year and saw even more control the second year than the first. And we just conjectured, this, that orchard stayed moist, which the nematodes like. It had a lot of pests to eat, so it recycled really well.
And there are a lot of other examples. I would say recently in the literature where you see these, persistent nematodes. And so I would say, our general thinking is still that you're likely going to have to apply again the next year, but sometimes not. that leads into a comment that was on Facebook and another really good comment.
This was from Matthew from Georgia. So Matthew writes, I rear and use nematodes in May and June they do work, but there is some concern that lab grown nematodes have lost their ability to persist from year to year,
is this a problem that they persist? Are they going to cause problems for us? I'm just thinking of certain types of insects that have been introduced and caused problems over time.
like, let me see, what used to be called gypsy moths. was that not introduced into the silk industry? And now it's a major pest. So could these nematodes cause us problems in the future? Now it's called spongy moth, I think. Ah, spongy moth. Okay. But, yeah, so it's a good question. the nematodes, first of all, we generally use ones that are already endemic to the U.
S. and there are some countries that would not allow a species to be applied that doesn't occur already. There's been a lot of research on impact on non targets like beneficial insects like lady beetles and that, and it's overall found that, the impact is either nothing or just negligible in the long run.
So they seem to be beneficial overall and really not a threat to the environment. certainly, Much less impact than any chemical insecticides, so they're deemed to be positive and, because they generally won't recycle at high levels, that's in a way a plus, there was one study in, Ireland where they showed that the introduced strain of a nematode was, less of a threat for long term persistence than the endemic nematode.
So. Overall, I would say that very safe to use and not a threat to the environment as far as the lab read ones. any nematodes, we've done a lot of work on what you call trade deterioration like anything else. If you repeatedly culture them again and again, you can lose beneficial traits like virulence or reproductive capacity and that.
So it can be important to introduce it. new wild type material into the culture or to use, like inbred lines, like purebred lines, like we use for corn and cow and other commodities or hybridize the strain. So there's definitely ways around that.
But I think the idea of farmers growing their own nematodes is a great idea.
We just developed and were actually published on a method for farmers that they could grow their own continuously. and we're expecting maybe to do a video on that sometime this year. So I think it's a very nice idea for farmers to be able to grow their own. But of course, there are many commercial, sources as well.
that's fantastic. So I'm glad Matthew mentioned that. so it is possible to grow your own. Perhaps you can give us a link with some instructions. can you give us a quick summary, like where you get your nematodes from and how you get them to multiply? Bye. So, basically. we get, we, in our method, you have a tray of, say, waxworms, or the easiest nematode, the easiest insect to use as a host because they produce a lot of nematodes, and you could buy them anywhere pretty much in North America.
You can expose that to an initial inoculum of nematodes, say one dead insect that has the nematodes in it, or a little bit of formulated nematodes that you start with, And once you start your, you should never really need to get any outside source nematodes because those insects will die. The nematodes go into a gel formulation that you can either store in the fridge or apply in the field, and then use that gel or infected insects to, to start over again and produce another round of nematodes.
But it, the paper was published in Journal of Insect Science. last year, and so, I can provide a reference for that. And like I say, we're working with partners also in Wisconsin, Sean, Stephan on a method that he developed as well that I think some cranberry growers are using to produce their own nematodes.
That is so incredibly empowering. It means that people are not going to be reliant on expensive inputs. that's incredible. That's wonderful. we've got a bunch of questions. Let's see who has written us here.
This one is from, B. let's see live podcast question. Our new orchard is fenced around our chicken coop and yard.
Is there any danger to applying these in the yard as the chickens are free range? No, yeah, they're, safe to any kind of vertebrates. Okay. Yeah. So no, not to worry. So they're not going to attack chickens or, little chickens or whatever. It's good question. You got to ask these questions.
Yeah. George asks, are nematodes male and female? And if so, do they work in harmony? We love the show from Toronto, Ontario. Thank you, George. Yeah. So. There's basically two families of these beneficial nematodes, the steininum adidi and heterobdidity. The heterobdidates When they, the first generation, when they get into host, all of them are going to be actually hermaphrodites.
then subsequent, generations, they'll have males, females, and hermaphrodites. The stein anema, Those only have males and females, except for one species, Tynanema hermaphroditum, that has hermaphrodites, but that's a rare exception. So, yeah, they have males and females that, yeah, I guess you could say they work together.
One cool finding from a Irish group was that, they found that sometimes the males will fight with each other inside the insect, inside that insect for, reproductive rights with the female. So, like sea lions, or elephant seals and all that, the males will fight each other and strangle each other, all kinds of drama going on inside the insect.
It's brutal. Oh my gosh. Oh, what a, what an existence. Okay. let's see,
Brett writes, I don't know where you're from. I heard that nematodes need to be watered in for the application. Is this true? It's a great point. they have to be, The nematodes have to be, remain moist in order to survive and also to move.
They need a moist soil environment to move. So yeah, it's best to water them in and keep that soil moist during the period that you want them to be working. Gotcha. Okay, so they have to be watered in. All right, there are so many more questions I have, and I want to go into a little bit more detail about the different insects that they can help us with.
But in the meantime, I'd love to take a few moments and just listen to the commercials from our sponsors. David, are you okay staying on the line for just a moment or two? Sure. Okay, . Thanks. You are listening to Orchard People, a radio show and podcast brought to you by the Fruit Tree Care training website, orchard people.com.
This is Reality Radio one oh one.com. And I'm Susan Poizner, author of the Fruit Tree Care Books, growing Urban Orchards and Grow Fruit Trees Fast. And my new book, fruit Tree Grafting for Everyone and we're gonna be back right after the break. If you're thinking of planting fruit trees and you're looking for a wide selection of
cultivars, consider Whiffle Tree Nursery. Our 62 page full color catalog includes over 300 varieties of fruit and nut trees, berries, grapes, and other edible perennial plants. Not only In our catalog, we help you through the selection process with tips and advice about all aspects of growing fruit trees.
You can learn about adding nitrogen, fixing plants, rootstock choices, and even about planting a windbreak. If you have a windy site, we're a one stop shop as we sell fruit tree care books, pruning tools. Organic sprays and natural fertilizers. We're located in Elora, Ontario, but we can ship all over Canada.
Call us at 519 669 1349 to order your catalogue. That's 519 669 1349. Whiffletree Nursery. Call us today.
If you're listening to this show, you are passionate about fruit trees. But, do you care how your trees are grown?
Silver Creek Nursery is a family owned business, and we grow our fruit trees sustainably using only organic inputs. We stock a huge range of cultivars, like Wolf River, an apple tree that produces fruit so large you can make an entire pie with just one apple.
We also carry red fleshed apples, like pink pearl, as well as heirloom and disease resistant varieties of apples, pears, apricots, cherries, and more. We ship our trees across Canada, and we can also supply you with berry canes and edible companion plants to plant near your trees. At Silver Creek Nursery, we grow fruit trees for a sustainable food future.
Learn more about us at silvercreeknursery. ca.
Do you want to grow fruit trees that thrive? Then don't miss a single episode of the Orchard People radio show and podcast. It is packed with insightful interviews. expert advice, and all the fruit tree care tips that you'll need to grow healthy and productive fruit trees. Sign up for our monthly newsletter at orchardpeople.
com slash sign up and you'll get all this juicy information delivered right into your inbox. Plus, you'll get early access to our latest videos, in depth articles, and sweet deals on our online fruit tree care education. Whether you're a seasoned orchardist or just starting out, we've got something for everyone.
That's orchardpeople. com slash sign up. Join our community. And let's grow together.
Hi everybody. You're listening to Orchard People, a radio show and podcast brought to you by the Free Tree Care training website, orchard people.com.
This is Reality Radio 1 0 1, and I'm your host, Susan Poizner. So in the show today, we have been talking to David Shapiro Ilan. He's research leader and supervisory research entomologist. And he works for the USDA Agricultural Research Service, and we've been discussing fruit tree pest control with beneficial nematodes.
So in the first part, we talked a little bit about what these little tiny nematodes are and how they can protect, help us protect our fruit trees from pests. And we're going to get into a little bit more detail in just a minute. But first, I would love to hear your questions. If you're listening to the show live, whether it's on reality, radio, one Oh one.
com or on YouTube live, just send us an email with your question or your comment. Or you can also just write us to say, hi, send that email to info at orchard, people. com that's info at orchard, people. com. And remember to include your first name and where you are writing from.
So David, oh my goodness. we have been talking about nematodes and how these teeny tiny things can make a difference.
What kind of differences have you seen in the test? Sites that you have. Can you give me some concrete examples of what pests you have defeated with the help of these little nematodes? down here in, middle Georgia, we target especially pecan and peach pests. And we've seen the nematodes do really a great job in killing peach tree borers, especially lesser peach tree borer.
The peach tree borer or some people call it greater peach tree borer that goes into the roots. We can get consistently as good a better control targeting peach tree borer compared with the standard chemicals such as chlorpyrifos, which is been more recently restricted, in many areas, but then the antipathogenic or beneficial nematodes have always done as well or better than, than those chemicals and killing pitubora, against, pecan weevil.
We've also gotten very high levels of control. so we're talking, with peach tree. borer and pecan weevil, 90 percent and above. Levels of control. so, just, they can be highly effective, but, as mentioned previously, it's best to use the appropriate nematode species for each target, to apply them in a manner that keeps them alive, with, irrigation or keeping the soil moist.
I had mentioned a protective formulation if you're applying them above ground. for your time. we developed like a, gel that's used most often as a fire gel. So it protects houses and other structures against wildfire. we thought it would protect the nematodes too against desiccation and UV, and it does a good job at that.
There are other protective formulations that you can use as well if you're applying above ground.
And so with each pest, I'm assuming the timing is going to be different, depending on their life cycle, like for instance, with peach tree borers, when is the absolute right time to apply the nematodes?
We like to apply them really, towards the end of the egg laying season, which would be, really about September, October here, depends on where you are. And then the nematodes will cuddle everything that's there, those that already started to bore into the tree and maybe some that are just getting there.
And then we might do a second application in the very early spring when the soil temperatures are lower. warm up just to clean up anything that's remaining. So yeah, the timing is very important. Thinking about And you have to know who your pests, who your pests are.
So I guess the reason I want to know is many of the listeners to this show are home growers, and each and every one of us has a different challenge, a different pest that they're fighting.
How can a home grower be empowered to use these beneficial nematode products? you can do a lot of research on the web just to see which nematodes are best for which target pest or contact someone like myself, if you're not sure, me and a colleague, at Lewis at University of Idaho, putting out a book this year, on antipathogenic nematodes as biological control agents and, that will have, the target pests listed for, Many, different commodities, including various fruit trees and other commodities.
So you can look for sources like that to find which nematode to use. And most of the companies that sell them will have good instructions on how to use them as well, and also information on which nematodes they recommend for the target pest. That's fantastic. I don't know if there's something you can share with me that I can put on the show notes like just whether it's a chart or a listing of the different pests, maybe a different species of nematode that's appropriate and a timing.
So maybe David, after the show, you and I can chat about something like that because it would be so empowering for people.
We've got an email from Sarah. Stephanie, and I'm really glad Stephanie, you emailed me because, I know that Stephanie's one of my students and she has a great question. Hi, Susan, listening on your program, I'm here in the high desert of Mexico and have discovered root knot nematode.
nematodes. Does David have information on destroying these guys? What about drowning them? And any ideas about how to buy good nematodes in Mexico? So these are great questions. We've been talking about the good guys, but there are bad guys. I don't know anything about root knot nematodes. Do you, can you explain to me what they are, David?
Yeah, as we mentioned in the beginning, there are many nematodes that are serious pests of crops, the bad nematodes, you might say, and, we're focusing today on the beneficial nematodes, the insect killing nematodes, but there's a fair bit of research that's out there. on using the good nematodes to kill the bad nematodes, such as root knot nematodes.
And the root knot nematodes will attack the roots and they form these little nodules that you can see. So, a lot of people that are growing tomatoes or carrots in their garden might pull up and see these little root nodules there, and those are likely the root knot nematodes. but that whole group, among the different plant parasitic nematodes have been probably the most susceptible to suppression by the beneficial nematodes.
They don't kill them out directly. There's some evidence that they produce certain, chemicals, allelochemicals that, suppress the plant parasitic nematodes. or sometimes there might be some kind of competition for space and whatnot going on. but there has, there is evidence, of suppression using the good nematodes against the bad.
Or, we were, we're doing some work right now using the bacteria, the symbiontic bacteria from our beneficial nematodes, particularly against the bad. The plant parasitic nematodes and seeing some good results with that. So the root knot nematodes, can they also affect fruit trees or just tomatoes and vegetable plants?
Oh yeah, no, they're definitely, many fruit trees have significant, plant parasitic nematode problems. Peaches. Pecan. okay. So this is serious. So the bad guys can somehow get in to the tree through the roots. And how do they mess around with our fruit trees? The bad ones. They stay, they're going to be attacking the roots and then just, basically draining the tree, causing, a decline.
and various diseases. So they drain the tree, they drain the tree of nutrients or of moisture? They're attacking, yeah, they're attacking the roots. and causing damage. Okay. So there, these are something like root knot nematodes or other bad nematodes. They can take out your trees, not a good thing. So you've mentioned that possibly good nematodes can help, by killing the bad ones.
How before, this beneficial nematode products came out, how did growers protect themselves from root knot nematodes and other bad nematodes? So there are a lot of, pesticides and nematocytes that are called that kill the plant parasitic nematodes. Many of them will be chemical based.
There are some organic products that can be found to use against the plant parasitic nematodes. previously, there were a lot of stuff that had a fair, Heavy environmental impact, like methyl bromide and just across the board, governments and other agencies have tried to get away from methyl bromide because of its environmental impacts.
So, looking for alternatives that are softer on the environment and there are products out there that can be used. Okay, so now Stephanie's last question is any ideas how she can source good nematodes for Mexico, in Mexico? It'd be hard. I don't know offhand if that, if there are companies selling there, you'd have to research that.
And if not, then that's a good place for the grow your own amateurs. That's right. And we will provide a link. David and I will chat after the show. We'll figure out what link I can send you, Stephanie, so that maybe you can grow your own. Pet nematodes to enjoy and help you with your fruit trees. We got a good question from James here.
James says, where do we buy nematodes? Are they available commercially or do we need to go to a special garden supply store? They're definitely available, commercially, and you can go online and find various sources. you can, you can compare prices and that, and, see which ones you want to buy and see which species you need.
So, so yeah, they basically, James, you're gonna have to do your research. I bet you, that there's probably stuff available online as well. I wonder for sure. Yeah, for sure. Yeah. Yeah. So, so that's terrific.
Now. So something that I was wanting to ask you here, hang on, a lot of insect pests that affect our fruit trees.
are not, cannot, you can't help us. Nematodes can't help us with some insects. Is that correct? are there, sorry, yeah, there, there's, there, there are some that are not susceptible, or at least challenging sometimes, but not often because they just, the, nematodes can't get in or they don't win the fight against the immune system.
but other times maybe they're just not reachable. which, which is not common, but possible. there's a prehonest beetle, which is a, longhorn beetle. That's, tree past, like in pecan and some other hard words. For example, we've tried in the lab sometimes to put a lot of different really.
like many nematodes that really should kill almost any pest. And these guys are like a tank. They seem like they can't be penetrated. but so far, maybe we haven't used the right species yet. So we're still trying, but that's just an example. but it does vary which pests you're talking about. for us, we always want to make sure that there's sound literature Field testing that's been done, in experimental studies showing a high level of efficacy before anybody would go out and use, the nematodes against the target past and I'm sure there must be some insects that just don't have a life stage when they're in the soil.
Maybe. so then they would not then they'd be immune from well, like, like I say, like some Insects above ground, if you apply them with a protective formulation, you can kill them. So like lesser peach tree borer. you can kill when it's in the tree, in the peach tree or plum tree or whatever.
You just have to spray that wound and use some kind of protective gel to protect them. Okay. So now Eric asked this question, can you say more about getting and using the gel for above ground use? I'm thinking in terms of. Peach tree borer, excuse me, they bore into the tree, can you squeeze the gel into the hole and somehow they'll work their way up and find the peach tree borer and kill it?
Is that what you would do? We found that even just spraying the tree with a suspension with the gel in it, or spray the nematodes and then the gel on top, then you, you're going to get the nematodes will go into that wound and find them. there's various, any kind of gel that you could, By, maybe viable, the one that we use in particular that you would see in our publications is called barricade gel.
That's the fire gel that we've used, but others have used other kind of gels too. And, so what's the future here?
You guys, I'm sure you're not alone doing this research. are there quite a few people researching this? There are, around the world, and, we just had our 100th anniversary of discovering these types of nematodes.
So there was a big meeting in Spain, to celebrate that hundredth anniversary. And there's a lot of really good things going on for the future. one exciting thing that we're doing is we found that these nematodes talk to each other with pheromones, the way some people think about how some insects talk to each other.
so that. We can then use those nematode pheromones to direct their behavior. For example, you'd, tell the nematodes, hey, now it's time to go out and find an insect and attack it. So we found that if you expose the nematodes to these pheromones before applying them, they're going to disperse more and they're going to infect more.
So there's actually a company now producing Those pheromones, that we're partnering with, company that we've published some work with. so that's really exciting. all the work that we're doing with a look to the future.
We did 1 experiment where we sent the nematodes into space. to the space station to see if when people will eventually be living in space and growing crops in space.
Can these nematodes do their job? Can they navigate in soil and find insects and attack them? so that you can use them instead of using, more harmful agents. And we found that they did do their job and do very well in space as well. So your nematodes went to space. Yes. Oh, my gosh. What was that like?
it was a great experience. we got to go. They gave us a lab, and this was also in collaboration with Incorporated.
We got to go to the Kennedy Space Center. They gave us a lab to set everything up, and then we got to watch the launch. First hand and then nematodes,
they splashed down a month later, and then we checked them out and made sure that they killed the insects and did everything they're supposed to, so we published a nice paper on that as well.
Unbelievable. it's very interesting potential here.
A few more comments that were on Facebook that were interesting. Luke writes, I don't know where Luke's from, Luke writes, I've been using beneficial nematodes for years, primarily for ticks. However, insects still come in off my property, so, A, I didn't realize that they could, also kill ticks, which is, great for, not spreading Lyme disease, that would be wonderful, but, what Luke is saying is, you're still getting more ticks, crawling in somehow, or do they fly, I don't know, do ticks fly?
No. So how are they getting in from the rest of his property? ticks, they're going to disperse in various manners or aren't a lot of times they're going to be carried by the animal that they're attacking. I would think would be a primary mechanism that they're dispersing any kind of distance.
But we've done work on ticks to against, Especially cattle fever tick, which is a very bad, tick that spreads disease to cattle, and in Texas and working with a colleague down there, John Goolsbee, we, they, have cattle as well as antelope that they grow for meat there. And, we developed, like, this smart sprayer when the animal comes to the feeder, the camera sees the animal and then sprays the nematode.
Onto the skin of the animal so that the nematodes will kill the ticks on the animal, so that was a nifty, way to go after those ticks. Wow. Yeah, those are, those guys are tricky and they're very, dangerous.
Paul writes here, in Indiana, I've considered, nematodes as an option to help control rose chafers.
So, have you seen any? Any evidence that works? Yeah, those are scarab. they'll, what and white grubs and a lot of the white grubs are susceptible to the nematodes, especially Japanese beetle. Some white grubs are more species are more susceptible than others. But yeah, they're definitely one of the targets.
Yeah, Japanese beetle is a nightmare for those people who have it bad, the trap seemed to just attract more Japanese beetles. So, so this gives people hope.
Then we've got North from Austin writes, I've used it in combination with surround. this interrupts the reprodu reproductive process cycle over time.
Remove any fallen infected fruit from the property. When the tree is fruiting, I'm vigorously shake the tree in the morning and night. And I've had my first good harvest this year. So, yes, this is an interesting point about using it in combination with other products like Surrounds Organic Spray. Yeah, and maybe he's using it against, plum curculio, which would be a good way to go at it because surround can be, one of the organic approaches to plum curculio.
And then if you get a fruit drop, you're using the nematodes in the soil. That'd be a nice combination. The nematodes are compatible with a lot of different, other products, but it does depend on which ones and the timing and which things. target pests you're using. For example, people who use imidacloprid, a lot of times the nematodes will be synergistic with that compound.
They've also sometimes been synergistic with a Beneficial fungus, like, called matter is, and many examples, such as against white grubs, there'll be synergistic with each other, meaning the amount of control you're getting is more than you'd expect, by the sum of the parts, Bavaria is another insect killing fungus.
and in that case, sometimes it's, advantageous and synergistic and sometimes not. So you do have to explore that, to see if they're all compatible or not. That's a very good point. So you have spent. 30 years, 30 years studying nematodes. You're an entomologist. You could study lots of things.
How come, what is it about nematodes that fascinated you 30 years ago that made you take such a deep dive? I guess I fell in love with them. I started out really interested in biological control and, and gravitated towards, insect diseases or biopesticides. That are used against the, the insects.
I started really working on insect viruses, which are also, a great, there's some great biopesticide products based on viruses, but then I started studying the nematodes and stuck with it. I did a postdoc with Fulbright, and studied with Edemol Glazer, who was a great leader in that field and just really pushed me forward.
that's very cool. It sounds like you've made a big difference in developing new strains and, helping growers of all sizes and scales. what advice do you have for home growers who are dealing with these pest problems? what did, what would you suggest? I would say, consider the nematodes, for the past that you're having problems with.
look at the literature, and go on the web and see if there's, good levels of efficacy against that person, how to use it. And, you can contact me if you like. If you don't find the information that you need, we'd be happy to help you. Oh, that's fantastic. And again, you and I will also have a conversation.
We'll make sure lots of information is in the show notes to empower people to grow their own or breed their own nematodes, to know which nematode, strains to use with which problems.
So I want to thank you, David, so much for coming and spending this time with us on the show. And you explain what is a complicated topic in a really accessible way.
And I really appreciate that. I enjoyed it. Thank you. So to the listeners, if you want to learn more about today's topic, we are going to have lots more information in the show notes, and I'm going to put up the recorded podcast within the next day or so. So if you want to find that, you need to go to orchardpeople.
com and you can click on podcast. You'll go to our podcast page and you'll find this episode and there'll be lots more information, but there's also lots more shows. And so you might want to subscribe. You can subscribe to our podcast on that page. You can also go to our YouTube channel. I'm going to put up a video of this conversation with images of some of the things that we discussed.
So if you want to see what we're talking about, as well as hear what we're talking about, go to Orchard People's YouTube channel. And while you're there, you can click on subscribe and any new videos will come to you. And finally, I highly recommend if you are interested in fruit trees, if you want to grow them successfully, go to orchardpeople.
com slash sign up. And there you can sign up for my monthly newsletter where I will tell you what the upcoming podcast is. And I also recommend information about seasonal information about fruit tree care to help you grow fruit trees successfully. So I really appreciate you guys for joining me on the show.
today, I appreciate David for coming on the show and we have another show coming up next month with another great topic, so hopefully I'll see you. Then bye for now, everyone.