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How Do Pesticides Affect Honey Bees? Ft Reed Johnson Ph.D

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Show Notes

How do pesticides affect honey bees? Find out in this episode of Backyard Bounty podcast as we join Nicole as she chats to Reed Johnson Ph.D.

What You’ll Learn

  • How do pesticides affect honey bees?
  • Why corn planting can lead to Honey Bee deaths
  • What is being done to reduce Honey Bee death from pesticides

Our Guest

How do pesticides affect honey bees? Today we will ask and expert! Reed is currently an Associate Professor in the Department of Entomology at The Ohio State University in Wooster, Ohio. He teaches two courses at Ohio State: one on the biology and practical aspects of beekeeping and the other on pesticide toxicology and application. His research focuses on determining how bees are exposed to pesticides and measuring the effect that toxic exposure has on the health of honey bees with the goal of promoting bee health in the context of modern agriculture. All of this making him an expert on answering the question – How do pesticides affect honey bees?

Reed got his start in research beekeeping while looking for a summer job in his hometown, Missoula, Montana. He knocked on the door of Dr. Jerry Bromenshenk at the University of Montana, was offered employment, and was quickly drawn into the world of bees and their biology.

Reed went on to receive a Ph.D. in Entomology from the University of Illinois at Urbana-Champaign working with Dr. May Berenbaum where he was involved in the honey bee genome project.

Reed then moved to a post-doc position at the University of Nebraska with Dr. Marion Ellis where he explored drug interactions between miticides in bees.

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Announcer: 0:01

Welcome to the Backyard Bounty podcast from, where we aim to educate and inspire you by sharing practical information to help your homestead thrive. And now, here's your host, Nicole.

Nicole 0:17

Hello, everyone. And thank you so much for joining me for another episode of Backyard Bounty. I'm your host Nicole, and today I'm joined by Reed Johnson, who is a Associate Professor in the Department of Entomology at The Ohio State University, and focuses his research on honeybee health and pesticides. And so obviously, that's what we're going to be talking about today. So read, thank you so much for joining me today.

Reed 0:42

Thanks for having me here, Nicole.

Nicole 0:44

Absolutely, you came highly recommended by several of our previous podcast guests. So I'm really excited to talk to you and learn more about your research and your research findings, of course, but can you kind of just give us a little bit more of a background on your research and your history with pollinators?

Reed 1:04

Well, I guess if you want to go way back, I got started working with honeybees when I was an undergraduate and I just got a summer job at the University of Montana in Missoula, where I grew up with Dr. Jerry Bromenshenk there, he hired me to be a Bee Wrangler. I guess that's what you call, you know, your bees up in Montana. So of course, I was just a biology major looking for a summer job. And I never thought it would go, you know, further than that summer. But then I came back the next summer and I kind of got into bees and one thing led to another and I've got a PhD in Entomology and they hired me here at Ohio State to to do research on honey bees and other pollinators. I guess I just got really fascinated with honeybees and how they tolerate the toxic things that they encounter in the world around them, and how that affects them.

Nicole 1:52

It's funny how sometimes, you know, life plays out. I've heard that statement from many of my podcast guests just about, you know, accidental beekeepers that became so fascinated by them that it kind of just turned into one way or another lifetime, either profession or passion or it's kind of funny how they tend to suck you and I guess.

Reed 2:12

They certainly do. It's I mean, I guess the classic way to get into it is to catching a swarm, and then suddenly, you're a beekeeper. I wasn't quite that spectacular, but it does have a way of just sucking you in. Yeah, I just would never think of not working with honeybees now.

Nicole 2:26

Sure. So I know that you're currently doing some pesticide research, is that the majority of your research history or have you done other research as well,

Reed 2:36

Most of it has actually been on pesticides or on the molecular components of pesticide detoxification in bees, more recently starting to get into kind of broader issues about you know, where bees are exposed to pesticides in particular and what bees were actually foraging on. When they leave the the hive where do they go in the environment?

Nicole 2:58

So I guess diving right in what are some things that you've found that research?

Reed 3:02

Well, my I try to in my research, I try to focus on beekeeper complaints. I think that is a great lead in to finding a really good research question is if you can find a beekeeper complaining about a pesticide issue, that's a great place to start looking for is a pesticide really the problem here, which pesticide and how is it applied, that might be causing the problem. So we've we've done that in several scenarios. Here in Ohio, we're looking at we have looked at the effects of corn seed treatments, this insecticidal coating that they apply to pretty much all the corn seeds that are planted in the United States, and the effect of that insecticidal seed treatment on bees, particularly during the planting period, which is coming right up here, it might be very early spring, so it might be quite soon, the corn is being planted. And that's really when the bee exposure occurs at its highest. Because the problem with those corn seed treatments is it's, I guess, kind of think of it like a Skittle or an M&M, you have to chocolate on the inside. And then you've got this insecticidal coating on the outside. And just like an M&M, it's like brightly colored, they brightly colored that insecticide seed treatment to make it clear that you really should not eat this corn. But the problem with this is this it's not as well stuck to the seed as it probably should be. And so as those seeds are dumped into the planter, and then they are transported through the plants or with air pressure, a little bit of that insecticide on the coating chips off to make a insecticidal dust which is then vented into the into the air around the planter. And bees can definitely get exposed to deadly quantities of the the neonicotinoid insecticides used on those corn seed treatments while planting is in progress.

Nicole 4:52

Sure that makes sense because corn is wind pollinated, correct. So the pollinators don't actually do much with the corn is that well.

Reed 5:01

They will collect the corn pollen, I mean, bees do like wind collected or wind pollinated plants, they will go to those for pollen. And apparently they like sweet corn pollen better than field corn pollen. And so there can be an exposure later on after the plant is full grown and it's it's shedding pollen. But that exposure is just drastically less than it is when the seed has been put in the ground because by that time it's it's diluted throughout the entire plant and probably a lot of is has washed off into the soil. So the concentrations are much much lower in the pollen than they are during planting and you can actually get like acute bee kills. That can be spectacular. If the circumstances are right here in Ohio, that's going to be late April, early May when the corn is being sown, if any beekeeper looks if you're going to corn growing area, I think it's very likely that you'll see a small increase in the number of dead bees that are are outside in front of your colony. When corn is being planted in our work, it's usually about a doubling or a tripling of the number of dead bees ejected from a colony each day. Which I guess what I'm saying that it sounds like a lot, but it's low enough that most beekeepers probably would not even notice that there's a change, particularly if you got grass growing in front of your colonies. Those those dead bees will just never be visible. Despite I mean, that seems like a pretty drastic thing to lose a bunch more bees per day. But the colonies you know in April and May those colonies are growing so fast this time of year that it's it's just a speed bump for them, they seem to recover very nicely and are highly productive for the rest of the season.

Nicole 6:40

So do they then carry these pesticides into the colony or does it pretty much just stay isolated in that one worker and then just affect the individual beat?

Reed 6:50

Well, that's the real problem because this is a dust. And so the the bee that's out there foraging for pollen, presumably these are the classic because pollen is essentially a dust as well. And that's the problem with the secretement dust is it's it's similar in size and properties to pollen. So upon forger or even an actor forger, this dust is going to stick to the hairs on that bee. And then if it's foraging for pollen, it will get mixed in with the pollen that bee is collecting and will get stored on the bees legs in those those beautiful pollen balls that honeybees collect. And so those pollen balls may have a significant concentration of these insecticides in them. But that foraging bee is fine because she's not eating the pollen. You know, bees of that age don't consume pollen. So she transports it back to the colony and unloads it in a pollen cell for her younger sisters to eat. You know, the nurse bees are the primary consumers of pollen in a honeybee colony. And they come and you know, eat and eat the pollen, and then they die. So it's probably the nurse bees, these younger bees inside the colony that are hit hard. And that's why we're seeing dead bees in front of the colony. Those are the nurse bees that were poisoned from this insecticide exposure.

Nicole 8:02

And then does that go on to affect the young bees or any other of the castes in the colony?

Reed 8:08

You know, we looked for that and no, you just get a an increase in number of dead bees during that period, I would assume there's probably some effect on the larvae. Because of course, you're you're knocking out a bunch of nurse bees. So those larvae probably aren't going to be cared for as well as they would have been. But there's surprisingly little effect from this exposure. Aside from just seeing a bunch of dead bees when the corn is being planted. We did this study on we've done it on 13 different sites around central Ohio over multiple years. The appearance of those dead bees is very reliable during burn planting. But the the long term effects just just don't seem to be there.

Nicole 8:45

Well, I guess this is a silver lining. How do they present you said they they're really reliable? What do they look like?

Reed 8:53

So I mean, it's just they look like dead bees there, they don't look like anything special. Really, it's just that there's more of them than then you would expect to see, we have never gotten to observe a really spectacular bee kill. And it is possible. I think if the particular if there's errors made in applying that seed treatment to the seed that the formulation is off or something, you can get much more of that seed coating coming off of the seed and that's when you can get really spectacular bee kills where you you do see large, obvious numbers of dead bees in front of colonies. And those colonies actually can collapse if if there was a misapplication of the seed treatment on the corn, and those are reported occasionally. There was a big incident in Germany back in 2008, where the whole bunch of seed was not properly coated and then there was just like apocalyptic bee losses when that when that corn was planted. So I think thankfully they have improved in in keeping this insecticide on the seed but it's it's still a risk for for bee colonies. I guess depending on what your goals are with beekeeping it may or may not be a problem for you. I guess if beekeepers are looking to split their colonies right after corn planting, they may not have as many bees to split as they would have if they had not been exposed to that corn planting exposure.

Nicole 10:10

Sure. You know, this is something that here in southern Colorado, we don't have corn crops here. So this is something very unfamiliar to me. So I find this unfortunate, but very interesting. Has there been any attempts with the growers to try and reduce the amount of coding loss on the seeds? Are they concerned about that?

Reed 10:31

Oh, definitely everyone is, has been concerned about this. And I think that's why it's probably becoming less of an issue because the companies that make the that are selling the seed and making the the seed coating, they have no interest in having that drift off of the seed, it certainly is not a benefit to the corn having that dust produced, and it kills bees, and they are certainly not in the business of killing bees. Sure, I think there have been some technical improvements to getting that that secretement to adhere to the seed on the upstream, the plants or manufacturers are also aware of this problem. And I think they're trying to incorporate new designs into the planters where the air is vented into the soil, rather than currently, it's just kind of up into the air. But that's going to be a long term solution. Because the planters that are out there right now really can't be modified to change that air venting. Most farmers really like bees, and they don't want to be killing bees with their corn planting. So there are some best practices just after planting, there's usually a bunch of dust left in the bottom of the plants or from this the sea treatment that's just sloughed off in the hopper. And a good recommendation is not to clean that dust out anywhere where bees are going to be encountering it not on top of the patch of dandelions or in an area where we're bees are going to encounter it. So just care in handling the seed and dealing with cleaning out of the plants or after planting is something farmers can do to reduce the bee exposure to these insecticides.

Nicole 11:55

Well, it's reassuring to hear that there's at least some, you know, attempts made to mitigate the problem, at least to some degree. So how do you go about actually testing and finding out, you know, the exposure levels and things,

Reed 12:10

The best way that we found is to use a pollen trap, and we just trap the pollen that the bees are bringing back in. And I don't know if you've seen a pollen trap. These are amazing devices. They're a series of screens essentially. And we use bottom mounted pollen traps. So the bees entering the colony, they go through this series of screens and that scrapes off those pollen balls on their legs. And then it collects in a drawer that you can pull out and you can empty that pollen out. We did it every two to four days. And then we take that collected pollen and we we send it off for pesticide residue analysis to find the the concentration of the secret and insecticides that that are in that pollen. And then additionally We've also looked at the plants that the bees have been foraging on. We've done some identification of the pollen since we have the pollen identifying which plants the bees were foraging on. And we attempted to figure out if particular plants were more likely to be contaminated with the seed treatment dust. It seems like they're all about the same. But it was a really interesting study just to see exactly what bees are foraging on in the spring corn planting period.

Nicole 13:17

And so what are some of the predominant plants?

Reed 13:19

Well, it actually changes day by day.

Nicole 13:21

Oh, really?

Reed 13:22

Oh yeah, it changes. I mean, honeybees are incredibly dynamic in their foraging, and they change depending on what is blooming and what's being most productive. So before corn planting, it was largely the the mustards and mints, as well as tree pollen here in Ohio, that would be like Oak or Maple or even Ash pollen, then using corn planting around here happens right about the same time the fruit trees are blooming. So we see the fruit trees and the plants in that that rose family all bloom roughly the same time, including the brambles and the blackberries that we get along the field edges. And then after planting, it starts to see willows and and other honeysuckle starts to show up. And so it was actually really fascinating just to see how much it changes over just a few weeks, and the bees are foraging on completely different things from week to week.

Nicole 14:12

Wow. How neat. You know, I was familiar with the concept of, you know, what's, what's in season or whatever, you know, this is booming right now. But I guess I didn't realize that it changed that frequently.

Reed 14:25

And I mean, they're there, they... yeah, they switch it up a lot. It's it's pretty amazing. I first mentioned dandelions, of course dandelions were important earlier, earlier, before corn planting as well.

Nicole 14:36

Sure. So what are some of the maybe most surprising or most unexpected things that you've found along your research?

Reed 14:45

Unexpected things? Well, I guess relating to this quarantine study, the most surprising thing we found out of that whole study? Well, number one, you know, bees are definitely dying during corn planting, and that that really should not be occurring. I mean, that's good. Clearly it's pollution is occurring here with this insecticide release. And even though the colonies do recover, I still think it's unacceptable that this stuff is being released into the environment in that way anyway. But the colonies do appear to recover, at least in in the environments that we were following them in. And then we found a strange thing as we follow these colonies through the subsequent summer and into the fall. And that's that the colonies that were exposed to more currency treatment dust were around more cornfields, those colonies were actually doing better by the end of the season. And so I mean, it might be tempting to say that maybe there's some weird, beneficial effect of insecticide exposure. I don't think that's the case, I think it's that these highly agricultural environments where there is more corn planted, at least in Ohio, we think those are actually better environments for keeping bees in than the more forested or urban environments that were, we were comparing them to. So I that was that continues to kind of surprise me is that agricultural areas, at least here in the Midwest seem to really be the the premier place to keep your bees if you want to do well, and for honey production. And strangely enough, that's where most of the commercial beekeepers in Ohio, keep their bees is out in among the corn and soybeans. So I guess that just validates that that's a that's a good place to keep bees, if you can make money keeping your bees in that environment.

Nicole 16:30

Sure. I mean, yeah, that's not really what you would think, you know, you think, "Okay, well, the toxic potential the corn, so don't put your beehives there." But that's really interesting.

Reed 16:39

I mean, then the question is, what is it about that environment? I mean, clearly, the insecticides are not good for bees, I think that's, that's pretty well established, I think it could be that there's just a lot less managed land out there, you know, you've got the various weeds in the roadsides and the field margins, as well as the soybean fields. I mean, soybean is potentially a good nectar source. It does produce nectar and does draw bees to it. And so it could be that those huge soybean fields are actually a big contributor to the success of bees in these agricultural environments, at least here in Ohio,

Nicole 17:13

I guess, yeah, yhat would make sense. Yeah. I'm sure you've got your your water source, and you've got nectar and pollen, I mean, that kind of satisfies most of their needs anyways, that are maybe harder to find, and especially in urban environment, or out in the forest, like you mentioned, something you wouldn't think.

Reed 17:30

Yeah, so we're trying to figure out what if soybean is actually driving that. And I mean, I guess soybean, there's a whole nother realm of insecticide exposure in soybean because they do apply insecticides and fungicides to soybean while it's in bloom. So there's another potentially large exposure that's happening there. I mean, apparently, at least in the colonies, we were looking at it didn't harm them substantially. But I think there's a real risk for for pesticide exposure here in the Midwest environment from from soybean pesticide applications during bloom. So that's, that's the direction we're heading in next.

Nicole 18:06

And have you looked at the effect of these pesticides on pollinators other than honeybees,

Reed 18:11

I really focus a lot of my research on honeybees anymore. But these I mean, all the same. Certainly the insecticides are, are at least as devastating and possibly more devastating to the solitary bees and the bumblebees just because they don't have you know, this social environments to help sustain them I think a honeybee colony with you know, 20 to 30,000 individuals that's like a really has a lot of buffering capacity. So you know, you it's really not that much skin off their back to lose several 100 bees to this pesticide exposure for a honeybee colony. But if you're a bumble bee Queen out there trying to found a nest and you get hammered with you know, a seed treatment dust exposure, I think I mean that that could be the end and you're just colonies just I mean, that be may die and the the larvae feeding on that contaminated pollen maybe really compromised. So I think honeybees are probably uniquely resilient to exposure, at least in this scenario, but the solitary and bumblebees are probably much more exposed to this. So I think I mean, it's definitely a concern.

Nicole 19:15

So that makes me think of a question that might be totally way left field and I don't know what your climate or season is really like up that direction. But you mentioned the the bumblebee queens, do you have any issues with Virgin queens going out on their mating flights at the same time that the corn is being planted?

Reed 19:35

Um ,there probably are a few but that's usually just before swarming really kicks in so there's it's probably not as many as it would be if it if the corn planting happened later.

Nicole 19:45


Reed 19:46

It's definitely concern I'm sure a queen could pick up this dust as well. And I mean, I'm not sure that she grooms herself but the her retinue was probably going to get a dose of insecticide from putting that stuff off of her.

Nicole 19:59

So you I mentioned in the beginning that, you know, for the backyard hobbyist beekeeper, they might not necessarily notice the addition of new or double the amount potentially of dead bees out front. Other than being aware of the corn planting season, is there any telltale signs of pesticide exposure causing these losses, just you know, for the backyard beekeeper to be aware of?

Reed 20:24

So with the the neonicotinoids the death if they just looked like dead bees, I mean, I guess one signal could be that if you find particularly young bees being ejected, but I think for the backyard beekeeper, and for most beekeepers, it's even getting to see the dead bees is really a challenge. So people might want to consider, you know, putting some cardboard or old carpet, you know, putting your bees on some sort of concrete pad or some surface where you can actually kind of inspect what kind of dead bees are those Undertaker bees dumping out in front of the colony. I mean, I think it has other value as well for beekeeping. If you have a deformed wing virus problem, looking at those dead bees is probably going to pick it up pretty quick when you start seeing, you know, bees out there with with twisted wings. So I think it's just generally a good thing for beekeepers to do to keep the front of the colony clear so that you can actually observe the dead bees, I think they are another stream of information that can help you understand the problems that your bees are having, and certainly can help you pick up on on big spikes and dead bees that might be associated with a pesticide exposure.

Nicole 21:31

Sure. So going back to the seed coating, since it does go into the air, is there any concern about that being then spread with wind or anything? Or is it pretty isolated?

Reed 21:44

It's probably not isolated, these are small particles. I mean, our suspicion is and I we have not done the air sampling that would be needed to support this. But I suspect there's just a big cloud of insecticidal dust over the entire Midwest during the corn planting season, because there is so much corn and it's all planted, usually within a week of each other incredibly intense planting activity. And so I think we just get a whole lot of dust in the air. I mean, we did detect seed treatment dust at apiary sites, miles away from the nearest cornfields that were being planted, it was at much lower concentrations. But it's it's pretty clear this stuff is getting up into the air and and moving with the wind over a relatively large geographical scale. So...

Nicole 22:31

So it could definitely impact folks that aren't necessarily within foraging range of a crop?

Reed 22:37

it could depending on the wind, I mean, it does appear that the higher concentrations are associated with being near more cornfields short, but if the wind is blowing the right way, and there's a application problem with seed treatment, it is possible that someone away from a cornfield could observe this kind of bee kill event.

Nicole 22:53

So you mentioned that the the soybeans, but what else do you have in your kind of future research? Or do you have any specific questions that you're hoping to answer or goals or anything else?

Reed 23:07

Well, I can tell you about the other side of our pesticide research. Yeah, which is really focused on almonds. Oh, and of course, almonds are the 8000 pound gorilla in beekeeping. Because everything revolves around almonds, we have you know, 80% of our, our managed honeybee colonies in this country going to service almonds for pollination each winter. And they do apply pesticides to almonds during bloom, right while the bees are present. And so the other side of my research program has really been looking at, you know, what are the effects of the pesticides applied to almonds during bloom on the bees that are out there. And we've especially been interested in looking at combinations of pesticides, because it's very common for a pesticide applicator and almonds to mix several different products together to make one application. Okay, and the problem is, is that all of the testing done on these pesticides to evaluate their bee safety is done on on individual compounds, it's it's never done on kind of real world combinations as they're actually applied in the field. And so we're trying to fill that gap to see, you know, of the field relevant combinations, you know, the combinations that the applicators are actually using in almonds, are there any of those that are likely to kill bees or to affect the development or to affect Queen development and cause Queen issues? And so we've just been looking at the whole suite of fungicides that are applied during bloom in combination with the handful of insecticides that are are quote unquote, be safe, that are also applied during bloom and maybe tank mixed with those fungicides that are also applied.

Nicole 24:51

And what are some findings that you've did what are some things there are others that you found so far?

Reed 24:56

Well, you can kill bees if you get the combination right.

Nicole 24:59

Oh, sure.

Reed 24:59

The fungicides on their own, at least for causing acute bee death, the fungicides appear to be be safe. There may be subtler issues with some of the fungicides that they're applying, which is good news because fungicides are applied to essentially all almonds. Unless they're under organic production, it's very likely that fungicide is going to go on during bloom when bees are exposed insecticides you add an insecticide to that and that insecticide may be be safe on its own. But we found that a particular group of insecticides, the chlorantraniliprole, which is the active ingredient in altacor, and insecticide that is approved for use when bees are present, if you mix that altacor with a fungicide, particular fungicide called tilt, which has the active ingredient propiconazole, then you can start killing bees, despite the fact that the tilt and the altacor alone are relatively safe. You can't kill bees with them. And we've replicated this in both you can if you spray adult bees, you can kill them. If you feed this stuff to honey bee larvae, you'll kill those larvae. This particular combination appears to be bad news, and maybe responsible for some of the kind of sporadic reports of bee losses that beekeepers have been observing when they're pollinating elements.

Nicole 26:17

And so why do you think that that combination is especially fatal?

Reed 26:21

Well, I could get deep into the weeds on this. I think it's because so there's actually a mechanistic reason this group of fungicides that tilt belongs to, they kill fungi by inhibiting a particular enzyme called the the cytochrome. P450s. is actually a big family of enzymes. But this, this fungicide inhibits that group of enzymes, which then makes it so the fungus can't produce the hormones that it needs and it dies. All living things have the cytochrome P450. enzymes. And we think what's happening is in honeybees, this tilt inhibits P450 activity in the bees. And then these particular P450s are the ones that are important in detoxifying that altacor. And that's one of the reasons that ultra core is so safe for bees is because they're really good at detoxifying it. So the same group of enzymes is the is a group of enzymes that detoxifies caffeine, for example. And this is the reason that we can consume me in particular, very large amounts of caffeine without suffering any apparent ill effects. So same thing with honeybees, they can they can consume large amounts of chlorantraniliprole or altacor without ill effects until you inhibit that enzyme that is allowing them to tolerate that that insecticide. And that's what's going on here is that that fungicide inhibits that P450 enzyme. And what was not toxic is now toxic, because it can no longer be metabolized by that P450 enzymes.

Nicole 27:43

So with that research, would you then be able to encourage farmers to apply them separately?

Reed 27:49

Well, that actually the route we've taken and this this work has all been done with funding from the Almond Board of California, and they have been really eager to incorporate the findings into the recommendations to their own growers, their recommendation has just been to not use insecticides, when bees are present. So a much simpler a much broader recommendation. And I think they're comfortable making that because there's and this is kind of the dirty secret of a lot of pesticide applications is that there's no documented benefit of applying an insecticide during bloom. It's it's not solving any problem. And therefore Why are they even doing it? If it's costing their growers money, and it's killing bees, there's just no reason to even be using this insecticide during bloom. And so they've actually been advising their their membership to not use insecticides during bloom. And and it's worked the the amount of insecticide applied to California almonds has really fallen off a cliff. I think we're down to 30% of the insecticide used in 2018 versus 2014. Before this, they started making that recommendation. So it's the rare case where I think this research has actually led to a recommendation and people are using less insecticide now which is which is great. That's probably the thing I'm most proud of, of anything I've done is that this is actually changed practices and reduced pesticide use on the ground.

Nicole 29:16

Absolutely. I think that that's a wonderful achievement. And I applaud you for that. That's fantastic.

Reed 29:22

People actually listened. It's great. It's...

Nicole 29:26

I'm sure it's very fulfilling to see that your your work is is then causing some positive changes. And I think that's fantastic. And so are you working on then any other research right now?

Reed 29:38

I guess to continue with the almond story, the next phase in that is going to be the spray adjutants and so this is another kind of mysteriously dark corner of the pesticide world. The spray adjutants are our products that a pesticide applicator will add to their tank to improve the Pesticide Application characteristics to improve the of the spray quality or the sticking of the pesticide application to the plants, or to improve the penetration of that pesticide through the, through the leaf surface into the, into the tissue of the plants. They serve all sorts of functions. And if you look at if you look, there's there's hundreds of different adjuncts that people are using. And, again, we're looking at almonds in California, California actually has a very unique system where they have a publicly accessible database for every single Pesticide Application that goes into agriculture. Everywhere in the state, going back to the early 90s. See, you can actually look to see what people are applying each year. And there are dozens of different pesticide ads events applied to almonds during bloom that are going in that tank, with the fungicide with the insecticide and potentially with other adjuvents as well. So it's it's really a mixture of a number of different products. And so we're looking to see if we if we add these adjuvents in there, does that alter the toxicity of the fungicides and insecticides that are also going into that tank mix. And what we found is that this the same combination of altacor and tilt that was toxic, together, though they were not toxic. Individually, if you add in a spray adjuvent on top of that, now you're really seeing, you know, market the mortality even at you know the the application, right, you're probably going to be killing bees, killing them dead in the field, if you mix that particular combination together. So the spray adjuvents are problematic. And there's some indication that these spray agents may be toxic to bees just on their own, depending on the rate that they're applied. There's really been very little research into the interaction between bees and bee spray agents. There's a new research out in in California Davis doing this now and but it's definitely an area that needs more research looking at these agents and their their bee toxicity.

Nicole 32:00

Sure. And so that's something you're going to spend some more time on?

Reed 32:04

That's that's the goal is to look at a broader range of fungicides in combination with more of these dozens of adjuncts to see if that can explain some of the mortality that some beekeepers have been observing. And currently, the recommendation is to just really avoid use of these adjuvents. Because again, there's there's not a huge amount of evidence that they improve the Pesticide Application. So again, the board is just recommending don't apply, spray adsorbents during bloom either, which I think is a really common sense. recommendation.

Nicole 32:36

So with these, both these applications, what they're not being a whole lot of evidence that they're even effective and what they're intended to do. Is it just something that's kind of tradition for lack of better terms, or why do you think they do that?

Reed 32:50

Well, I think with the spray adjuvents, I think people really need to learn more about why those things are actually being used. It could be that there are benefits that I don't understand, because I'm an entomologist, I'm not a plant biologist, or I mean, it's I think really getting to the bottom of those benefits and how much adjuvent until you really need to realize those benefits. But I think with the insecticide they saw adding that insecticide as cheap insurance. And because they do have insect pests and almonds, they have the peach twig borer is the pest that is supposed to supposedly control even though this is really a poor time period to making to be making an application to control that pest. But I think they just saw Well, if we can add it, we got to make this spray application anyway to put the fungicide on the cost of adding in an insecticide is quite low, because we're already making the application. So why not just add it in there as a little insurance in case there happened to be any peach twig boars out there that we can knock out for really minimal costs with this application. So I think it's it's kind of convenience and and just looking to, I guess mitigate any risk that that might be there, even if it's not particularly effective risk mitigation.

Nicole 34:05

Sure, that makes sense. And then when they apply these pesticides, are they doing them during the day, or are the pesticides you know, active for long enough that even if they applied them in the evening, that the you know, it would still affect bees for some period of time.

Reed 34:20

So the recommendation is it has been for some time to apply pesticides and almonds in the evening. But that doesn't definitely not always happen and they could be applied during the day. All of these things are labeled such that they can be applied really at any time. There's no prohibition against application when bees are actively foraging. So I think that's that's a really good way to reduce the risk to bees is to do that late day application after the bees have already exhausted the pollen and nectar from the Allman flowers for that day. And I think that's that's protective because in many plants, those flowers that are open on one day, they're going to close up and it's going to be a whole new batch of flowers. Ours that are going to open up fresh and new the following day. And those will be relatively uncontaminated. I mean, there may be a little bit that gets in there. But I think that's a really good way to really reduce the exposure to the bees get for not just for almonds, but for, for many crops, and many Pesticide Application scenarios. If you can make that late day application, most plants are going to put out new flowers in the morning. And those are the ones that are most attractive to the bees. So they may really not encounter much pesticide at all, if you do this this late day or evening Pesticide Application.

Nicole 35:30

So as with all of the different research that you're working on, if you could have it your way. Is there any other changes and things that you would like to see implemented?

Reed 35:43

changes? Well, I mean, I honestly I think this this issue of insurance application of pesticides, people applying a pesticide, when it's not really needed, I really would like to see that stop. I think it's number one, it's it's there, I've been looking at bees, but who knows what else these pesticides are killing or harming out there in the environment, there may well be you know, that there's the solitary bees and all these other bee species as well as aquatic organisms and a whole range of other organisms that could be affected by pesticide applications that aren't really serving any productive purpose. I always enjoy working with specialists, you know, in these cropping systems in soybeans, and corn or in almonds to to talk about what are these applications actually justified? And is the simplest way to protect bees, just to stop making this Pesticide Application that really maybe not is not actually all that useful to begin with? Yeah, I come back to that again and again. And even going back to that first study, you know, with the corn seed treatment dust, there's actually not a lot of evidence that that insecticidal seed coating provides a huge benefit for corn growers. Again, it's viewed as cheap insurance. In most cases, it doesn't actually kill any insect. Yeah, I mean, it kills bees. And there are situations where growers do have problems with like a seed corn maggots consuming that that corn seed before it has a chance to sprout. But I think in many cases, a grower knows which fields are going to have that issue and could order seeds that are coated with the insecticide for that specific, you know, scenario. But in this country, right now, it's almost impossible for someone to buy corn seed without this seed treatment insecticide on it, they've got it locked in. So if you want to buy any of the new, most developed varieties of corn, it comes automatically with a seed treatment insecticide on it. The grower has no choice, but to apply that that secret when insecticide, so I'd like to see people have the ability to make the decision, you know, and to only apply insecticides or any pesticide, when it really is justified given the situation. And I think that would that would protect bees and protect a lot of other things in the environment as well.

Nicole 38:02

Sure. on that, I think that that that absolutely makes sense. And hopefully, in due time those changes can be made.

Reed 38:10

I can, I hope so too.

Nicole 38:12

So obviously you have a lot of really exciting research going on and research that has made some actionable changes, which I get, I think it's just fantastic. What is the best way to to either follow you and follow your research or get more information?

Reed 38:29

Well, there's a Bee Lab website. But that's probably one of the best ways to keep up with what's going on in the Bee Lab here. And that's that website is managed by my colleague, Denise Ellsworth, who's with Extension here at Ohio State University.

Nicole 38:42

Wonderful, and that has your current research and stuff on there as well?

Reed 38:46

I hope if it does not I will go and make sure that it's updated.

Nicole 38:49

We'll post that link and make sure that people can find it.

Reed 38:52

That's great!

Nicole 38:53

Wonderful. Well Reed, thank you so much. I really enjoyed talking with you today. I've learned so much. This was such a great episode. Thank you. Thank you so much for your time and your expertise today.

Reed 39:03

It was great. Yeah, I really enjoyed talking with you, Nicole.

Nicole 39:06

And for those listening. Thank you so much for joining us and we will see you again next week.

Announcer: 39:12

For more from Backyard Bounty text the word "Podcast" to 719-292-3207 or visit See you again next week.

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