0:00:00.0 S1: Welcome to another episode of the making sense of biological campaign. It's a new weekly series that'll take a dive into various topics with unbiased experts in the field of biologics. This episode is made possible by pure crop on an all organic formula when you just want one tool that does it all, an insecticide Fund decide bio-stimulant and super surfactant containing only seven plant-based ingredients per crop, one is naturally safe for the planet humans, animals and even beneficial insects. For more information, visit per crop 1 dot com. Today, we are joined by a biological control specialist, Mark Hoddle at UC Riverside. Mark, you are not on US land right now. You are out of the country. Is that correct?
0:00:40.2 S2: That's drive, I'm doing a six month sabbatical down here in New Zealand.
0:00:43.7 S1: Very good. We're glad you could take some time, it was a little hard to coordinate with the time differential, you are a day ahead of us, which is... So you technically your time traveling...
0:00:53.6 S2: Yeah, that's right. So we're a day ahead and a few hours time change, even though it's a day ahead and it got a little bit complicated because of the change in daylight savings in the US, but I tell you figured it out, man, and you knew the link at the link at the right time, and here we are.
0:01:08.0 S1: Thank God for Google. So we're talking today because a case study that you have... You had done some work and your lab had done some work on hydrogels for ant baits, let's talk about that complexity first, so ant baits... trying to find a good ant bait that isn't going to have some complications.
0:01:28.4 S2: Right, so that traditionally should growers try to control ants in their orchards, they have really only two options, so if we look at Citrus, for example, they have core first various sprays, which they can put on to the tree trunks, or onto the soil, those dry reduce killed foraging workers ant numbers drop. However there's a couple of problems with that approach. First, Chlorpyrifos use is going to be banned in California starting early next year. So I think December 31 its use is going to be severely rolled back. The second thing with putting out barrier sprays like that, is that it doesn't kill the subterranean Queens, which are living in the nests underground. So if you don't get the Queens, they keep breeding and the ants come back, the other thing I have to take my hat off to these ants is that they're really good at finding ways around these barriers sprays when we put them down, you know they find bridges, they crawl across sticks, or they touch the barrier and they run away and look for another place to go foraging. So part of the grant that we got from the California Department of pesticide regulations was to come up with some alternatives to controlling these ants to replace Chlorpyrifos, one avenue that folks have looked at have been the use of these plastic reservoirs,
0:02:39.4 S2: these plastic bait stations that you can buy. You fill them up sugar water, that's laced with an ultra low dose of insecticide, you place them out in the orchards, the ants come drink poison, take it back to the nest, kill the Queens. Very expensive to do, very labor-intensive. You need to pull these containers in probably every month, clean them, replenish them, put them back out again, and you need to use a lot of them per acre because these ants don't forage very far from the nest, maybe 30 to 50 yards. So it means you need to put out a lot of these plastic bait containers if you wanna hit the ants. So, what we were talking about with some chemical engineers UC Riverside was could we take these plastic bait station concepts and miniaturize them and make them biodegradable? And these guys said to us... Yeah, of course, we do that all the time. It's like, what really... What do you do now? There's this whole field, we call it hydrogel research, and we could make you a biodegradable hydrogel bead out seaweed and it will probably absorb the sugar water with the poison that you put in it.
0:03:42.1 S2: Gotta say, I was very skeptical... I'm often skeptical about a lot of this stuff. We made this stuff up got the beautiful beads, they look like tapioca balls that you'd sort of see in the bottom of your boba ice tea, you pick it up at your favorite Vietnamese or Thai restaurant. Okay, they look nice. We condition them in a 25% sucrose solution, which we put into a laser basically with a very tiny amount of Thiamethoxam, it was a 00001% concentration of Thiamethoxam, vanishingly small, the beads took up the product. Okay, they look good. We did some small lab trials, put them into containers with ant colonies, they came over almost immediately, they drank the stuff took it back to the nest, day later everybody was dead. I was like, ah okay, this stuff always works great in the lab it's a small plastic shoe box with ants they've got no choice, but they wanna eat this stuff or they starve. So again, very skeptical. Time to take it out to the field. We made many, many kilos of this stuff, took it out, put it on the ground underneath the citrus trees, the ants swarmed it, three days later, they were gone, and about that time, these biodegradable hydrogel beads were pretty much dissolved and melted away into the soil as well.
0:05:02.7 S2: So we put out three applications, about three weeks apart, about 250 grams of the stuff per tree we just got on our hands spread it out underneath the trees, we got about 12 weeks of ant control, they just didn't recover from those trials. We think that may be an underestimate of the efficacy of these beads because we had small plots within an orchard and around these treated plots, it was just a sea of Argentine ants waiting to push back in to take over that territory that other ants have left behind. We think if we did like an area-wide or an orchard-wide control program where we got rid of all the ants you would probably need to put out fewer applications and you maybe get longer levels of controls, you're not gonna have this constant re-invasion pressure from the untreated areas of the orchard. So a lot of potential where the California Department of pesticide regulations agree that this has potential and they decide the sponsor this work. So what we're trying to do now, let's take these beads and see if we can infuse into them different types of insecticides, that we think that can kill ants.
0:06:10.1 S2: We don't want to rely just on one product, say Thiamethoxam because we may end up with resistance to that product, so we've screened about eight different compounds, and these different compounds have different modes of action, so that should severely debilitate the ants' ability to develop resistance to these products, so we're doing the lab trials now, seeing how well those different compounds work, and we have the field trials planned for the spring of 2021 assuming that everything goes according to plan, we don't have another campus shut down because of the covid outbreak or something like that. So we're a little bit behind track now, we lost a big chunk of this last summer, these things have got shut down for us, but we've been doing lab work under very strict management conditions and we are making progress again now.
0:06:59.5 S1: That's really exciting. It's like an extreme targeted delivery system of a pesticide basically.
0:07:08.3 S2: Yes, so this is precision pest control, so I'm pleased you brought that point up because we're taking this a step further now, because another part of that grant was to determine where are the ants in the orchard, when do you need to control the ants... So if any grower goes out into their orchard, just that everybody knows us who's ever watched these ants, they love running along the irrigation lines that sit on top of the soil, they use them as super highways, and some behavioral studies have shown that Argentine ant is not only really good at not only linearizing it's roots of travel to get from nests to places to forage, they're also really good at avoiding rough terrain because if they walk over rough ground, it slows them down, and some lab studies have shown that as the irregularity of the terrain increases that they're having to walk over, you can slow them and down by about 42%, so it's no wonder they get off to do it, and the leaves and the twigs and the snail shells, and the brown garden snail shells or any other stuff that's underneath those trees, they get on those smooth plastic pipes, they're smooth, obviously, and the linear, and that's the two things that the ants love to get from their nests to the trees where they can go up into the trees, take the honeydew from those sap-sucking pierce,
0:08:25.3 S2: scare away all the natural enemies, so their livestock is being looked after, they're not losing it to predators or parasitoids, you can think of them almost as wolves picking off the sheep that these ants are protecting and harvesting the honeydew from... So the second part of that grant is that we then started talking to some computer engineers at UCR and see, you know when you walk into a shop and you hear that bell go ding-dong, you broke a beam and somebody knows you're in the shop. So I ask these guys, I said, Could we miniaturized that and put it on top of those pipes and have them count ants as they're running back and forth, just like the chemical engineers, it's like, Yeah, of course, we do this stuff all the time, they've got these miniaturized infra-red leds, and we can build 3D waterproof plastic housing, we can have all this stuff going up into the cloud, you can access it on an app that we can build for your phone, ok really skeptical yeah... Sounds great, guys. I wanna see it. So they build a few protocols, we clamp them on to these pipes, they had a little light on and sure enough as the ants are running back and forth they're breaking the infra-red LED beam the light's flashing, they had a little micro-card in the camera to record the data we pull that out, put it in...
0:09:45.8 S2: yes, we can see the ants going back and forth. Data looks great. They build an app for this. So what we're doing now is that we're in the process, actually, right now, while I'm talking to you, the guys are out in the field doing this we're putting out prototypes of these counters during the last defined tuning of the design, so these counters turn themselves on every hour for for five minutes and count ants, so these ants are being monitored in the orchard all the time, and our data have shown us that ants are active at night when people aren't out there looking around and especially if the weather is hot, you're not gonna be out in the middle of the day foraging, they come out when it gets cooler and people aren't around to see them, so you may think you don't have an ant problem, but in reality, you do, 'cause you just can't see the damn things. 'cause they're hiding underground. You go home for the day, they come out at night and they start going up and down the trees doing their business again. So with these counters, the data goes up into the cloud through the cellular networks that you use, exactly the same system is you'd use for your cellphone... connects to a cellular tower, it gets deposited in a cloud-based reservoir or loading spot.
0:10:55.3 S2: We have software there that summarizes the data, and because each of these counters has a GPS chip built into it, you know exactly where in the orchard the ants are giving you problems, so you can look at these data and decide, Okay, block three, go into row two through eight, we've got some pretty wicked ant problems in there, we just go and put the hydrogels underneath those trees for a few days and just knock those things out. So part of what we have done is that we know that when ants running along the tube on pipe across a certain level, we know that's related to the number of ants going up and down a tree trunk, we spend hours and hours sitting underneath these trees counting ants running on the pipes, counting ants running up and down the tree trunks, and we've come up with a mathematical relationship, so we know that if on average, you're seeing, I don't know just can't think what the exact numbers are just say on the pipe, the counters are counting on average, say, 100 ants a minute or something moving along the pipes, on average that might translate to say 30 ants a minute moving up and down a tree trunk, we know once you cross about 20 ants per minute going up and down a tree trunk, the bio-control services that are operating in that particular orchard start to go down, 'cause there's too many ants in the canopy of that tree, protecting those sap-sucking pierce from their natural enemies, so we know that we need to keep the ant numbers below about 20 per minute going up and down the tree trunk.
0:12:19.1 S2: So what we're hoping to do with all this is that'll be automated, you'd be sitting in your office or in the ATV or pickup truck going around the orchard, now what are the ants doing, you check it on your phone. You go, Right, okay. Most of the orchard is good, that area need some treatment. And you go out and dump the gels underneath the trees. Ultimately, what I think could happen, is that this whole process could be completely automated. You have your phone, but instead of you reading it, it goes off to a land drone or something that's sitting in the packing house or a storage ship somewhere, it loads itself up with the gels, it knows the GPS coordinates it travels out there at night, spreads them underneath the trees itself, goes back, charges itself up, gets another load of these gels and just works its way around the orchard, does all this at night, nobody in the orchard, temperatures are lower, humidity is higher, the gels have a longer activity period because you're not putting them out in the middle of the day when it's hot and dry. So, if we can pull all this off and fully automate this whole system.
0:13:18.5 S2: I think it would be a huge advance for the integrative pest management of not only Argentine ant, but the sap-sucking pierce and these trees or vines that these ants are looking after.
0:13:27.8 S1: So you have a couple of those technologies already, you've got the ___ and I think there's a couple other ones too that do the weeding and grapevines at night, and that would be really exciting. This being a biologics episode, I think it's interesting that in this fact, you are actually taking a biological and using that to help deliver the pesticide, they are working together in this one... Literally.
0:13:50.5 S2: Right, so that's the focus of this whole project, is we want to maximize... Or you can even think about synergize, the natural enemy community in these orchards. And the way to do that is to get rid of the ants. We've done a lot of work now, not only in our lab, but you've probably talked to Ken Diner as well, he's done a lot of work in grapes... There's a handful of us who have worked on these systems, and this work really stretches right back to the 1920s when the early citrus growers, for example, after Argentine ant invaded in around 1908 in Southern California, they noticed that their biocontrol programs really took a hit because the ants were so good at protecting these sap-sucking piece from their natural enemies and it's sort of been a battle ever sinse to figure out how can we best control these ants to get the maximum amount of impact from our natural enemies, and in this case, yeah, we're gonna have to use insecticides, but we're using vanishing ly small amount of insecticides to unleash the biocontrol potential in these orchards. I have to hand it to these old guys, now they really set up some damn effective guilds of natural enemies through all the foreign expiration programs they did. When we take the ants out, these pest populations collapse in about a month and they just don't come back.
0:15:08.3 S2: The data are very clear on this, our lab has shown it, Ken's lab has shown it. There's labs out of Santa Barbara, UC Santa Barbara that have shown similar results as well. Argentine ant is a major disruptor, you take it out, and the natural enemies really come in and do a great job for us and it's free pest control. Why wouldn't we wanna be using that, it makes economic and environmental sense.
0:15:33.0 S1: Well, and I think a lot of people still have a hard time wrapping their head around... Well, I don't have Argentinian ants, so I don't need to control them. That's not what it is. That's not what the problem is. It's not that they're causing damage to your crop, it's out there keeping other insects from keeping the other insects from damaging your crop.
0:15:50.9 S2: Is that... That's exactly right. That's the issue, the ants don't damage your fruit, they don't chew holes in your trees, they don't eat up the leaves, they don't do anything like spread pathogens around, they just protect these sap-sucking pierce from their natural enemies and you get rid of them in the bio-control agent really do a great job on psyllids, mealybugs, aphids, soft scales. One of the things we found out from this work, which was really interesting to us, is that California red scale numbers go down a lot when you control Argentine ant, but California red scale is a hard scale and it doesn't produce honeydew. It's like, Why does this happen? The ants get nothing from Red scale, they don't even, like, look after it. And what the work suggests is that even though you have ants running up and down the tree, if there's a group of sap-sucking pierce say, like brown soft scale or aphids that are in close proximity to red scale colonies, those red scales benefit from the ants just being present and moving around, 'cause they scare away aphytis, which is a really important parasitoid of California red scale, so just the presence of ants patrolling these trees tends to scare away a lot of the natural enemies and you get rid of the ants
0:17:02.9 S2: and non-sap-sucking piece also succumb to the biocontrol agents, 'cause the ants aren't just there patrolling and scaring things away.
0:17:12.3 S1: That is crazy again, the grant you got, the research, you're looking at his title, Taking Chlorpyrifos Out of Citrus, we'll look forward to following that and see how it goes. It's exciting and it's exciting that you guys are using these hydrogels with the deliverable being a biological... Again, UC Riverside biologic specialist, Dr. Mark Hoddle, I appreciate your time.
0:17:33.8 S2: Thank you very much too. It has been great chatting to you again.
0:17:36.5 S1: Again, this has been another installment of the making sense of biological campaign, it's a series to help spread the understanding of the biologics field with unbiased experts, and again, this episode was made possible by PureCrop1, an all organic formula when you just want one tool that does it all, and Insecticide Fungicide bio-stimulating super surfactant containing only seven plant-based ingredients. For more information, visit purecrop1.com