FARE-talk is to provide an enduring conversation about contemporary topics relevant to food, agricultural, and resource economics.
Brady Deaton: [0:04] Welcome to FARE Talk where we set out to provide enduring discussions on contemporary topics relevant to our economy with particular emphasis on food, agriculture and the environment. My name is Brady Deaton Junior of the Department of Food, Agriculture and Resource Economics at the University of Guelph. I'll be your host. [music ends] Today I'll be talking to Dr. Cynthia Scott-Dupree and we'll be discussing the science that informs our understanding of the relationship between bees and neonics, a pesticide that the Government of Ontario has recently made subject to new restrictive regulations. Cynthia is the Bayer CropScience Chair in Sustainable Pest Management in the School of Environmental Sciences at the University of Guelph. For the sake of full disclosure I note that Bayer produces neonics, I also note that Cynthia is a well-published researcher in the broad area of pest management and in the specific area that we are going to discuss today. Cynthia, thanks for coming and joining me at FARE Talk.
Cynthia Scott-Dupree: Thanks so much for inviting me.
Brady: [01:02] You're welcome. Alright so let's see if we can just kind of delve in and I'm not sure the best place to start but maybe we'll just talk about neonics and try to break that down and then we'll talk about bees and then let's try to talk about the science, so we'll have some of our terms. So, neonicotinoids and neonics, can we use those interchangeably?
Cynthia: Ah yes, neonics is much easier to say than neonicotinoids or neonicotinoids or whatever you want to say, so let's just call them neonics.
Brady: Alright then even within neonics there's three of them that are typically talked about and they have pretty complicated names too. Is it important that we understand that there's more than one kind of neonic out there?
Cynthia: [01:41] There's certainly several different neonics and there's actually different families of neonics and within those families their toxicity to bees can vary a lot, so again just within the neonicotinoid or neonic family it's complicated, but the ones they speak of most are imidacloprid, which has been around the longest and I would dare say that most of the research studies that anyone wants to read on them has been focused on imidacloprid. The second generation or newer neonics that are also seen, talked about in these research and other articles is clothianidin and thiamethoxam. But instead of just talking about those today I think we'll just talk in general about neonics.
Brady: Okay but even in the headlines I probably read I probably could have been referring to a study that was looking at a particular one of [Cynthia: Yeah] those neonics rather than all and that could be important to [Cynthia: Yes] some of those differences.
Cynthia: [02:45] It's true they have different toxicities but I think the more important thing here is to understand some of the basic characteristics of neonics and how they are used in an agricultural setting. For example, neonics can be used as a foliar so they can be sprayed on a crop. They can be used in furrow so they can be sprayed in the furrow when the seed is planted. They can be used as drenches, but more commonly they are used as a seed treatment and this is because neonics have a special characteristic. They are a group of systemic insecticides and this means that when they are applied to the plant they move upwards through the plant so they are in all parts of the plant tissue, and in the sense that we are today talking about impacts on bees, what can also happen is that these neonics will then become concentrated in the reproductive parts of flowering plants and that would be in things like the pollen, and certainly also the nectar because that's what bees will forage on. So you'll get residues moving to these sites, and that's the interface where these beneficial insects can be exposed to the toxins.
Brady: Alright, just step back a minute. You know we think about bees providing honey and they also are an important pollinator and that's an important input into agriculture production, but so is pest management, right? [Cynthia: Certainly]. Since the plagues of Moses we know that to have food we have to control pests and so [Cynthia: Absolutely] neonics are an insecticide that do that. What came before? How long have neonics been around? Was there another pesticide that they replaced? Is that important to the story?
Cynthia: [04:36] I think agricultural pesticides as we know them today were introduced after the Second World War. A lot of the chemicals we now use in agriculture were developed in terms of chemical warfare, and then afterwards after the Second World War they realized the potential use of them in agricultural applications, and so there’s a whole raft of classes of insecticides specifically or pesticides that have been introduced over the years. We won't get into those, but the more recently introduced group since about the 1990s, early 1990s, would be the neonics, and as I say the characteristic of systemicity or being systemic is quite unique to them. I won't get into a description of the particular characteristics, but the fact that they move through the tissues is valuable. Another form of applying chemicals, pesticides to crops is seed treatments, and I think I should spend a bit of the time talking about seed treatments I don't think a lot of people will understand this.
Brady: Yeah let's do let's talk about the seed treatment, because that adds the value right, to...
Cynthia: [06:04] Yeah. Well, seed treatments I've been a proponent of seed treatments for a long, long time because what you do with the seed treatment situation is you take a tiny little seed and you actually apply the treatment on the coating of the seed, and as the seed grows into a plant the insecticide, the neonic, moves through from the coating on the seed into the tissue of the plant, and therefore it's there from the beginning, so if you have insect pests that attack those plants from the time they germinate and they're just tiny little seedlings when they're very, very vulnerable they will be protected, certainly an advantage. The other thing is that when you utilize the seed treatment versus a foliar treatment where you're spraying a lot of product with water all over the crop and everywhere else, a seed treatment uses a tiny, tiny fraction of the amount of active ingredient that would be the toxin. And so it's advantageous in that way because the environmental impact is much reduced and certainly the people applying these treatments are much safer with a seed treatment than a foliar application.
Brady: Okay so I want to hit that back again make sure I understand it. So prior to this ability to treat the seed I guess if I all of a sudden saw a pest that was threatening my crop then I would have to go out and spray a foliage application and that had a different set of environmental implications. This way pre-emergent I can coat it and [Cynthia: It's protected] deal with the pest ahead of time, so it's almost an insurance policy.
Cynthia: [07:50] It is an insurance policy that in itself makes it a difficult situation because the whole entire seed treatment industry is a complicated one. A grower needs to buy treated seed in the year prior to planting, so by October of this year for example, growers would be buying treated seed to plant in the spring of 2017. So it's really difficult to predict what kind of pest you're going to have in 2017, we don't have this kind of crystal ball, although a lot of growers and pest management people wish they did, so it is an insurance policy [Brady: I see] because you do have to buy it well in advance and the cost of buying them is quite small in terms of the total amount it will cost to put a plant in per hectare. So it's insurance and it's difficult to understand how that fits within a pest management concept, but it's an important application technique in terms of seed treatments and we really need to figure out how to manage it better than we do because it's too valuable to lose.
Brady: Alright well before you go we'll talk about the science behind all of this but now let's turn and talk about bees a little bit. Bees, what I am talking about honeybees typically in these studies but it looks like wild bees come into this discussion, bumblebees. How should I think about bees in this discussion?
Cynthia: [09:32] Well I would say that a lot of the information people hear about is focused on honeybees because they are our domesticated honeybee the beekeepers have kept for thousands of years, and they are often associated with the pollination of cultivated crops, vegetable crops, fruit crops, any kind of crop that flowers bees will be attracted to and are likely beneficial to that plant in some way shape or form, so the bulk of our information is focused on honeybees but that's not to say that there aren't a lot of other bees out there that are really critically important to agriculture and lots of other ecosystems, not just agriculture, but natural ecosystems. When you go to Algonquin Park or some park and you look at the flowers blooming you will find bumblebees and other bees, bees other than honeybees. Not to get into too much science here, but the Latin name for honeybees is Apis mellifera, and so we call it an Apis bee and all the other bees are called non-Apis bees, just to really divide this quite easily. The non-Apis bees encompass bumblebees, leafcutter bees, orchard bees, stingless bees, there are a lot of bees out there that people just wouldn't even recognize because they don't all look like honeybees or bumble bees. I would say in terms of the non-Apis bees, people would easily be able to identify a bumblebee.
Brady: OK, I already just want to say for a minute two pathways of potential confusion for someone like myself that just kind of does a cursory look at this literature that you've already hit on, one is that neonics, there's multiple types of neonics, and when we talk about bees there's multiple types of bees, and the tendency would be for reasonable tendency for people with limited time would be to homogenize these all together but the science that we will talk about I think a little bit more requires that you ...
Cynthia: [00:11:30] The differentiation is critically important and the bulk of research is on honeybees even when we talk about submission of information to regulatory agencies that look after pesticides to ensure they don't have an impact on humans and the environment. That would be like in Canada it would be the Pest Management Regulatory Agency; in the US it would be the Environmental Protection Agency, those kind of regulatory agencies. In the past, most of the information to do with bee pollinators was submitted in terms of being represented by honeybees, but there's a lot of research that's been done now to show that different bees respond differently to the same pesticide. And so now there's a thought that we need to look more widely when we’re looking at new products that need to be registered, new pesticides that need to be registered and look at their impact on other bees other than just honeybees, and so a lot of the work that I also do in my lab is focused on these non-Apis bees because we've got lots of methodology for honeybees, but virtually nothing for these other bees. It's not so simple; we can't take our techniques from honeybees and apply it to these other bees because they function in a very different way.
Brady: [13:03] Alright, before we get into the relationship between the neonics and honeybees I guess we'll be talking about, let me just step back and say in terms of what we know about bee colonies, that's the most popular way it's described, where are we losing bee colonies, are we growing bee colonies? First of all, I just ask two questions. One is, what is really meant when we say bee colonies? What are people referring to? And second of all in Canada and then maybe in Ontario talk to me a little bit about how they've changed over time.
Cynthia: The colony that they're talking about, I don't know if you've actually ever seen how beekeepers keep colonies, they have them in these white boxes that stack up. Every stack represents a colony of bees, and it's usually the first two boxes on the bottom that contain the lifeblood of the colony, that's where the queen is and that's where the brood is. Any boxes above that are honey okay so they separate them out and so the beekeeper will extract those top boxes and take the honey off of them, so when we talk about a honeybee colony it's that complete unit, complete functioning unit, with a queen, a lot of workers, developing brood and these honey boxes are super stacked on top, that's a colony.
Brady: And is there variation in the population of a colony, or are they typically a certain number?
Cynthia: [14:25] They are overwintered by beekeepers. They have special overwintering techniques to keep them alive over the winter, but they're much smaller in the winter than they are in the summer. In the summer you can have up to 60,000 worker bees in a colony and a queen. And so, in all fairness in talking about bee losses we generally talk about it in terms of colony numbers. Occasionally you get media articles that say 20 million bees have died. Well you need to divide that by 60,000 bees basically in the peak of your summer population to determine how many colonies you are talking about. 20 million sounds amazing. [Brady: Colony is the appropriate unit.] Colony is appropriate.
Brady: Alright so what do we know about bee colony loss in Canada and Ontario?
Cynthia: [15:22] Well there's a lot of talk about honeybee colony decline, but if you look at the statistics from Stats Canada you will actually see over time in Canadian bee populations, we're talking colonies, the number has continually risen, specifically in the last 10 years. There are occasional drops in number, but if you average that out over time it's increasing and it's really critically important to look at these increases over a long period of time, not one or two years, because you get sudden drops and everyone panics, but in the whole scheme of things it's increasing. In Ontario the same thing, in the United States the same thing, so overall we're not seeing massive decreases in honeybee colony numbers, but one statistic you will hear is overwintering losses. This is the way beekeepers determine and government agencies determine how well colonies have done, it's this overwintering loss. You take the number of colonies you put into winter and the number that are still alive in the spring and from that you calculate overwintering losses. In Ontario particularly for the last several years overwintering losses have been around 35%, which is high. Typically we would aim for an overwintering loss of between 10 to 15%. If you look at the statistics provincially Ontario continues to be an anomaly, most of the other provinces are in this 10 to 15% overwintering loss range. Ontario for some reason higher. I can't really answer the question why that's happening, but it is a cause for concern for Ontario beekeepers.
Brady: [17:32] Well that's a perfect segue into I think the next section. So Ontario has regulations to reduce the amounts of neonics and presumably one of their concerns is that maybe one reason why Ontario is an exception is because of neonics, and that’s what I want to maybe explore a little bit. So maybe I'll ask a series of questions and we can figure it out because there’s two terms that are used in the literature, throughout this literature that are kind of used differently, and so one is "hazard" and the other is "risk" and you'll kind of see one like I just read I think one was that honeybees have been shown to be highly toxic, or sorry, neonics have been shown to be highly toxic to honeybees, so hazardous I guess, and then there's this issue of risk. Before we hop in just abstractly what is this distinction between hazard and risk, or toxicity and risk, or is there one?
Cynthia: [18:35] And now we peel off the layers of the onion, the complexity comes in and this is the difficulty for people when they read headlines is there's a mountain of information that you really need to understand. So hazard and risk are different and I think often people lump them together and they're totally different. In terms of long-term policy development by government, the concept of hazard and risk assessment, which is an accumulation of different types of information, both of those areas, both hazard and risk, need to be dealt with to develop really strong long-term valuable policy, science policy. Hazard deals with the toxicity of the chemical or toxin you're dealing with, plus the intensity of the exposure, and that would be things like dose and duration. So, if you increase the dose and or increase the duration, the two, if you look at these as two circles, toxicity, intensity of exposure, if you look at them as two circles if you increase dose and duration those two circles overlap more, and where they overlap is the hazard. Okay? But risk is another circle overlaid on top of this. Risk involves the probability of exposure. A honeybee is not 100% exposed to a toxin all the time 24-7 it's not going to happen. So you need to think of the realistic exposure in a field situation. How often will that bee be exposed to those potentially worst-case scenarios of toxin exposure? So that's a third circle of overlay and where all three of those circles overlap, that is your risk.
Brady: [20:38] Let's try to break this down into for some people that won't be in this area an example. You tell me if this is a fair example. The child Tylenol in my cabinet is a hazard, but when it's stored properly children aren't at risk. Is that kind [Cynthia: Yeah, yeah that’s true] of what we're getting at?
Cynthia: If that bottle is locked because usually they have childproof lids and it's placed in an area where they can't get them then the probability of exposure is zero. If they can get at them though there is a hazard because that Tylenol if they eat too many of them like candies then the dose and the duration is high, the toxicity is there, that's a hazard, but you can eliminate that hazard by storing it properly.
Brady: [21:43] Okay, so let's use this as the spring load and I'll just ask some questions. What do we know about, and how do we know, I guess I'll ask both at the same time, about the toxicity or hazardness, you can correct me, about neonics, or if you want to get into a particular neonic, fine. But let's just start there at the extreme: how do we come to that knowledge and what do you think we know?
Cynthia: [22:04] Okay so when we do and we're really focusing on studies that are done in a toxicological framework here and toxicology is complicated, but when we're looking at these kinds of experiments we divide them into three different categories and the first category we will call tier one category, and these are the laboratory studies. These are studies where we would take a bee and we would expose them to a certain dose of the toxin over a certain period of time in a laboratory situation, so it's very artificial. The advantage of these laboratory studies it helps us determine if a compound is toxic at all to bees, okay? And if there is toxicity and it reaches a trigger value, which are set out in a regulatory framework, it may tell us that we have to do more studies, we need to clear these up, we need to dig deeper and fill in the knowledge gaps. So we would go to a tier two study, and a tier two study is a semi-field study. It's moving more to a realistic realm we'll call it quasi-realistic because it's outdoors, we plant a crop, we put a big screen tent over this flowering crop, it has to be a flowering crop to attract the bees, and then we'll spray that crop in the tent with the chemical the pesticide we are interested in, we put a small colony of bees in that tent and here's the important factor and one of the main differences between your tier one laboratory study and this tier two study is the laboratory study focuses on an individual bee, but how do we know that bees live what do we call bees? We call them social, they live together in large numbers, they live together in a colony. So truly we need to assess the impact of these toxins on the colony not just an individual bee because these colonies can have 60,000 individuals. If they lose 10 or 15 or 20 bees it's not going to impact that colony at all, but if something happens to that colony that really decimates the numbers then the colony is lost that's the living unit that we are interested in. So if we do these tests at the tier two level and at that experimental level we get some indication of toxicity and we reach the trigger values again then it may tell us that we have to do more studies, and we move to the tier three studies. These are the large-scale field studies, totally realistic. The farmers go out, they plant their seeds as they normally would with the amount of chemical on them they normally would in the field and you put the bees out in the field and they're free flying there's no tent. So these experiments are extremely expensive, they're very variable and it's terribly difficult to deal with a bee that may not want to stay in that field. If you're dealing with cattle you can put the fence up and you can keep them there, but with a bee not so. So there are some difficulties with these studies and our idea with these three tiers is that there can be a lot of the tier one lab studies and fewer and fewer of the tier two and tier three studies.
Brady: [25:51] And that kind of makes sense to do the tier one if there's no toxicity there's no need to do…
Cynthia: No need to do any other experiment.
Brady: And they're the least expensive.
Brady: Okay so what do we know from those tier one studies about the relationship between neonics if that's a fair question.
Cynthia: It's absolutely obvious from well-done tier one laboratory studies that these neonics are toxic to honeybees and it's not really surprising. Neonics are insecticides honeybees are insects, so having a confirmation of toxicity at this level? Not surprising, but the really negative thing to do is base your policy just on these tier one studies.
Brady: [26:42] Sure a lot of people might you know, but you're saying that there's a methodology that has to consider all three, but when I get to the conflicting, back to our kind of our early theme that there could be these conflicting results various quotes out there, one is that there can be two statements can be you can find something in a tier one and not find something in a tier two or tier three. I guess you can't find something in a tier two that's not in tier one. That makes sense.
Cynthia: That's right once you're at tier two and tier three they've obviously found some toxicity in the first level. All science, all science at least biologically based science has to be confirmed in the field. Every scientist knows that what they do in the lab has to be taken to a very realistic plane and looked at and confirmed.
Brady: In order to understand risk.
Cynthia: To understand the risk.
Brady: But we can establish toxicity so let's go so that's established. So have there been a lot of the first-tier studies?
Cynthia: A lot. In the one paper, the PLOS ONE paper you referred to I think it says just over 70% of all the studies on neonics and honeybees are laboratory-based tier one studies and then there are a smaller group of the tier two studies and fewer of the tier three studies so just as I have indicated. Lots of lab, not so much large-scale field.
Brady: What are we finding as we move away from the tier one or the toxicity studies as we move to the tier two and tier three?
Cynthia: [28:23] Well based on the research I've done and I've done a lot of the large-scale tier three studying is that what we're seeing in these laboratory studies is not being confirmed in the field. Not in terms of what we would call acute mortality of bees and that means a massive loss of bees suddenly. These large-scale field studies do look at bees over a period of time, but one of the questions that people are raising now is, what happens when bees are exposed to a small amount of toxin over a very long period of time? Does it make them sick? Do they not fly the way they should? Do they not forge the way they should? These are questions that I think in this PLOS ONE paper are discussed as being knowledge gaps.
Brady: So that's an area that we will continue to explore. Would you say that the from your understanding of that broad literature I mean it's clearly you're identifying as a knowledge gap do you have a sense of how the small subset of tier three studies have come out? Are they consistent, do you find colleagues arguing with you, you know as economists we're always arguing with each other about everything so I don't know if it's the same in your field?
Cynthia: Well I don't think the people who do large-scale studies argue with each other because I think they typically find the same answers and they agree on the fact that what we are seeing in the laboratory studies doesn't pan out in the tier three studies. But the problem is that people who need to make decisions about how we move forward in terms of utilizing neonics in ecosystems don't always consider the finding of these tier three studies they just focus on the tier one studies, which show toxicity and scare people, but they haven't looked at the risk assessment. What is the probability of those insects being in the crop and what residue levels are they exposed to when they are in the crop? That's not looked at in a laboratory study.
Brady: [30:40] One aspect, and this is a nuance of the study that maybe we can shed some light on, there's sometimes a discussion of dusting in that planting stage with the treated seed and that there was some evidence that that had affected bees. What is that and what's that mean in this discussion?
Cynthia: There's really two ways bees can be exposed to neonics in agro ecosystems and especially when we're dealing with corn for example most of the corn in Ontario is planted with a seed coating of neonics on it. And actually it's not I'm in error it's not a seed coating it's a seed treatment, and this means there's a bit of a powder coloured powder coating containing the toxin that's placed on all the seeds. The corn is planted with very large pneumatic seed drills and this means that a high blast of high-pressure air is injected through these machines to shoot the seeds into the soil, and when this happens you get kind of scarification or dusting off of some of the powder coat of toxin that's around the outer part of the seed, and the exhaust system of these particular machines that you're using to plant shoots this contaminated exhaust dust up in the air and what can potentially happen is it's windy, and it often is during planting, that this contaminated dust can be blown into hedgerows and areas where there might be things like dandelions and other flowering plants blooming that bees will forage on, or it can get into the water or what not. There is a concern about that and a valid concern about that and this first raised its ugly head in Ontario in 2012 and if you go back and look at the information you'll see very high losses of bees around planting time that they associated with this particular contaminated dust off situation. But over the subsequent years they've really focused on mitigating or finding ways of managing this problem and things like putting a fluency lubricant in the machines so that there's less scarification and there's less dust off, modifying the baffles where the exhaust comes out so it shoots it down to the ground instead of up in the air and then another thing that's being worked on is polymer seed coatings so rather than a dusty coating they'll actually seal the toxin in with a polymer sealant so there can be no dust off. And over time since 2012 incidents associated with bee loss during planting have gone down substantially, so it's a really great example I think of how these situations can be mitigated if everyone works together for a common goal. The other side of the coin, and this is where you need to make the separation, is the potential exposure that bees have when they're foraging on a flowering crop, like canola, like any kind of plant that produces a flower, and those plants will produce pollen and a nectar and as I mentioned there's a potential of these neonics accumulating in the nectar and the pollen, and that's the interface for the bees. Most of my work is on the residues and nectar and pollen in flowering plants, my large-scale studies focus on that. We need to really clearly separate the two and because Ontario is a major corn producer in Canada, our particular problems may be focused more on the dust off problem in the spring rather than the residues in nectar and pollen. One thing I'd like to add is that western Canada grows a lot of canola, way more than you would see in Ontario and canola is that bright yellow plant that you see blooming in the spring out in fields it's really pretty to look at. You'll see some of it in Ontario not in the really southern part of Ontario but certainly north of Guelph. If you go to the West we're talking Manitoba, Saskatchewan, Alberta massive amounts of canola just yellow as far as the eye can see. They've been planting that crop, canola, with seeds treated with neonics for 15 years, and in all of those provinces they don't have any problems with high, unusually high overwintering losses of bees and none of the beekeepers out there are concerned about bee losses in association with canola that's very much interrelated with this neonics seed treatment thing. Canada's big growing conditions are big but I'm just bringing this up because agriculture you can't really generalize, everything does not fit into the same hat.
Brady: [36:09] So given that do you have any ideas of why this issue has been so contentious, why the Ontario government has moved in a fairly decisive way? Do you have any sense, is the issue the different ways that science is the complexity? Clearly we've laid out this is a complex issue, there's, just to kind of review, I think we've hit a couple you might add in, we have what neonic you're talking about, what kind of bee you're describing, the distinction between a set of hazard studies and risk studies that can coexist, something can be hazardous and that can be true, something can not be hazardous but not risky that also can be true statements. Is that what's going on here or do you have any other sense of why this issue has kind of emerged in the way it has?
Cynthia: [36:59] Well I think typically people feel very connected with honeybees. They feel that honeybees represent everything that's good and natural in the environment and any kind of situation where you end up being focused on the demise of the honeybee and any way I think it hits us where it hurts in terms of "oh my God the environment is not balanced anymore" and I think that's why anything to do with honeybees continually concerns the general public and this is great. It's good to see people concerned about the environment, but on the other hand if you want to be concerned about the environment you have to read broadly and educate yourself on the topic rather than just believe everything that you hear and we get a lot of information that's thrown at us. The governments try to protect the environment, they try to protect everyone's interests and sometimes decisions are made too quickly. I firmly believe that science policy or policy, agricultural policy any kind of policy has to be based on a real strong foundation of science and not just the little body of science you choose to focus on, but all that’s available, the complete story and this doesn't always happen.
Brady: [00:38:26] Well I hope that this FARE Talk if it does anything it inspires the people that listen to this FARE Talk to check out this issue more thoroughly, to challenge the ideas that you've heard here, look into the literature and read more I mean I think that's what at the university we strive to encourage our students and we also strive to encourage this audience to do that.
Cynthia: I would say that it's important to have an opinion, but your opinion better be an educated one.
Brady: I think that's a perfect way to end this FARE Talk. [Music begins] Dr. Cynthia Scott-Dupree, thank you very much for joining us for a very interesting FARE Talk.
Cynthia: Thank you it was great to be here.
Brady: Thanks for joining us for at FARE Talk. We hope you will continue to check our website for updates and the latest podcast.
[Music ends] [00:39:25]
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