MS. DIANE REHMThanks for joining us. I'm Diane Rehm. The mystery of the dying bees first hit the headlines in 2006. Since then, scientists have raced to figure out what's harming these insects, but they continue to die in significant numbers. Now, the Obama administration has released a plan to help address the issue. For this month's Environmental Outlook, an update on the health of our nation's bees.

MS. DIANE REHMJoining me, Jim Doan of Doan Family Farms and Larissa Walker of the Center for Food Safety. Joining us by phone from St. Louis, Dennis vanEngelsdorp. He's assistant professor of entomology at the University of Maryland. I'm sure you'd like to join in. Give us a call at 800-433-8850. Send an email to drshow@wamu.org. Follow us in Facebook or Twitter. And welcome to all of you.

MS. LARISSA WALKERThanks, Diane. It's great to be here.

MR. JIM DOANThank you so much for having me.

MR. DENNIS VANENGELSDORPThank you for having me.

REHMAnd Dennis, I'll start with you. I know they was a survey released in mid-May talking about the health of bees. Tell us what that was all about.

VANENGELSDORPThat's right. So for about nine years now, we've been surveying beekeepers across the country to figure out what the winter loss rate was and we quickly realized that losses only happening in the winter. They're happening in the summer as well. And so five years ago, we started monitoring summer losses as well as winter losses and then, annual losses, of course.

VANENGELSDORPAnd so this year was really unique. This past year was really unique in the fact that for the first time that we've been recording, we've seen summer losses exceed winter losses. So we saw summer losses jump to 27 percent, winter losses at 23 percent and that's really concerning because the summer, it should be paradise for bees. Everything is great and they should be doing really well.

VANENGELSDORPAnd here, they're dying at high rates, higher rates than the most stressful time of the year.

REHMSo has the overall population of bees actually gone down?

VANENGELSDORPWell, no, and that's a really important distinction. Beekeeping is really unique on many fronts and one of those fronts is the fact that when a beekeeper comes across a dead colony and they have a living colony, they can split that living colony in half, buy a queen and then they have two units. And so they're able to replace losses really quickly. But, of course, this doesn't come for free and what is the result of that, you have winter colonies and you also lose productivity.

VANENGELSDORPAnd so we're certainly not worried about honeybees going extinct. What we're worried about going extinct are those commercial beekeepers we rely on to move colonies around the country to pollinate because they can't afford to keep losing 50 percent or more of their colonies every year.

REHMJim Doan, does what Dennis is talking about jive with what you are experiencing as a beekeeper?

DOANIt is. We're seeing tremendous losses that we are trying to recover from, but we're not seeing that we're able to continue to make up the numbers that we're losing. We're losing far more bees in our hives than we can replace in a given year. And, you know, we started out back in 2006 with 5300 hives of bees. We're down to about 1400 hives of bees we're currently running. We just can't continue to build numbers.

REHMWhen did you begin to experience bee losses?

DOANWe saw our first big bee loss back in 2006. We'd actually, previous to that, had some minor losses that we were starting to see, but nothing where we would find whole colonies just completely dead like we did in the fall of 2006 going into 2007.

REHMSo you would look at a hive one day and the next day, they're all dead?

DOANNot quite that fast, but within a week, two week period of time, you had a big vigorous hive that suddenly just disappeared. And literally, there wasn't any bees left in that hive nor were there any dead bees around the hive. They were just gone.

REHMWow. Larissa, remind us why are bees so important?

WALKERI mean, bees are essential to our agricultural economy, to our food supply. It's estimated that about one in every three bites of food we eat is responsible -- we have pollinators to thank. Honey bees are, of course, incredibly important to our food supply, but we have many species of native bees and many other pollinating insects like butterflies and beetles and flies, and all of those really contribute to the health and diversity of our food supply.

REHMAre we seeing similar losses with those other insects?

WALKERWe are. We don't have as good of a knowledge about wild bee populations as we do with managed bees and honey bees, but we do know that wild bees, such as bumblebees, are suffering population declines. And certainly the Monarch butterfly has declined an extraordinary amount over the last 20 years, about 90 percent, so that's really concerning.

REHMSo let's go back, Dennis, to 2006/2007. Isn't that about the time when concern over these bees began? What happened?

VANENGELSDORPWell, that’s right and that's when we really started paying attention to these loss rates. It was actually a good friend of Jim, Dave Hackenberg, who -- I was the state apiarist for Pennsylvania at the time and he, actually that November, had bragged about how good his bees looked that year and he brought them down to Florida, as he does every year, and he came back a month later and he describes this scene that Jim has just talked about where he had to get on his hands and knees.

VANENGELSDORPYou know, when you ever open a hive, a truck, and you're in an apiary, it's a buzz. It's a loud noise. And it was dead silent and he got on his hands and knees looking at the entrances, describing this as a ghost town. By the time everything was said and done, he'd lost 2,000 of his 3,000 colonies in a very short period of time and we became aware that this was happening with other people, including Jim and people in California and so that's when we went with a team and we went out and we took a whole bunch of samples and we turned the term colony collapse disorder.

VANENGELSDORPI do want to emphasize that colony collapse disorder in our definition meant a very specific set of symptoms and it's really clear that these are not just dying with these symptoms. There's lots of things killing bees and so it's a bigger issue than just colony collapse disorder. I think colony collapse is very...

REHMSo how different, Larissa, is what we're seeing today from what we saw back then?

WALKERWell, I think, you know, one of the differences between what happened 10 years ago and what's going on now is that it's not as mysterious. There's not this disappearance of bees and a lot of cases were just, you know, hearing from beekeepers that their hives are weaker than they normally were. You know, the bees might not have vanished, but they're just not as healthy as they once were. And that’s the case, as well, with many wild pollinator species, too.

WALKERThey're just not as healthy as they once were and that's definitely a problem not just for our food supply, but for our environmental well being and our own well being as well.

REHMI gather we're also seeing specific problems with queen bees. Is that the case?

WALKERYes, certainly, and Jim can probably speak about that better than I can, but that's definitely a big problem for beekeepers.

DOANYeah, what we're seeing is hives just simply lose their queen for some unknown reason and the hive itself, a lot of cases, does not try to replace her, which is not natural. Normally, a hive, if they kill the queen or the queen dies, they simply replace her. They take an egg that's viable and make a new queen.

REHMHow long do queens usually live?

DOANIn the old days, it used to be a queen would live three, four years. Today, we're seeing queens that aren't even making it 60 days.

REHMAnd what do you think is going on?

DOANWell, there's a variety of things going on. I mean, we're seeing certainly are areas that were habitat -- that were good habitat for bees are disappearing. But we're also seeing more use of pesticides out there and that's certainly a concern that we have for our bees. And, you know, we've also learned that mites are a bigger issue than we originally thought they were and we're seeing some new viruses that are out there that were not known prior to 2006.

REHMHow much does it cost to keep bees today?

DOANWe run with a figure about $200 to run a hive of bees for one year.

REHMAnd how many bees are normally in one hive?

DOANNormally, this time of year, there should be 70 to 100,000 bees in that hive.

REHMIn one hive?

DOANIn one hive.

REHMAnd so you've got how many hives?

DOANWe've got about 1400 right now.

REHMWhoa. So it gets pretty expensive.

DOANIt gets pretty expensive to take care of bees, yeah.

REHMSo if that queen dies in one hive, is there any effect on other hives?

DOANNot on other hives, but what happens is we have to -- in order to fix that hive back up to make it a viable hive once again, we're gonna have to go rob bees or brood out of another hive or hives and put into the hive that we want to reestablish and we've also either got to buy a queen or buy a queen's cell that we can put back in that hive. And that's not cheap.

REHMAre queens expensive?

DOANQueens are very expensive today. You're gonna spend $20 for a mated queen. You're gonna spend $4 to $5 for queen's cell.

REHMHuh. So you're spending lots of money to keep hives going.

DOANWe're spending lots of money.

REHMAll right. I want to let listeners know we invited the EPA, the USDA, the White House office of science and technology policy and all declined to appear on the program this morning. I'd sure like to know what's going on there. Short break. We'll be right back.

REHMAnd welcome back. We're talking about bees, the concern regarding their lifespan, the concern regarding what is killing them off at greater rates than at one time earlier. Here's an email from Jake in Rochester, New York, who says, I found data that from about 2001 to 2006, the average hive death rates were 16 to 20 percent. The 40 percent we're having now is obviously unsustainable. But what are the average growth rates during the year, and how did they compare then versus now? Dennis, can you answer that?

VANENGELSDORPWell, I think I can. I think that when we look at the number of bee colonies in the country, as counted by NASS, the National Agriculture Statistics Service, what we've seen since the World War II, a steady decline, from 6 million to 2.5 million colonies. However, since CCD happened, we actually see an increased number of managed hives in August in this country, and the reason for that increase, we think, is because beekeepers have contracts, to fulfill pollination contracts in February in almonds. And so what they're doing is they're saying, well, if I'm going to lose 30 percent, and I need 1,000 colonies to get -- to meet the contract demand, I'm going to have 1,300 colonies instead.

VANENGELSDORPAnd so we've seen this increase in numbers of colonies managed by some of the large commercial beekeepers as an insurance against these 30 percent losses.

REHMI see. Sort of -- well, I won't go there, but Jim, how different is beekeeping today from what it was, say, 10 years ago?

DOANBoy, 10 years ago we didn't keep bees more than 50 miles from our house, and today we're keeping bees, you know, three to four hours from our house.

REHMReally?

DOANBecause the area that we live in has developed so much into big agriculture that we cannot sustain bees there. And so we're having -- and all beekeepers are.

REHMWhy not? Why not?

DOANWell, because there's lack of forage, there's more pesticides being used, and so it's just not good areas to keep bees. And the other thing is that the bottom line, we were losing 60, 70 percent of our bees throughout the season, and that's unsustainable.

REHMBut were you doing, as Dennis says, making up for that by increasing the number of hives?

DOANWe were making bees up, but we weren't making them up at the rate that we could keep going.

REHMGot you, yeah.

DOANAnd Dennis is correct, and a lot of people are gearing up to go to California, but we're also seeing a lot of bees being lost throughout the season and beekeepers going and buying bees from other beekeepers, and so there's this huge bee market going on, and everybody's moving bees into different directions. You know, last year there was reported there were more bees in North Dakota than ever, but it's because everybody was going there to try to hide their bees from all these agricultural areas, which are not sustainable for bees any longer.

REHMLarissa, can you talk about that?

WALKERSure. I mean, you know, I think Jim hit on the issue really well, in that these areas where there are monoculturals, essentially just fields upon fields of one crop, leaves little diversity for bees to have a, you know, diverse and nutritious diet with many different types of flowering plants. And on top of that, you know, on top of the not having access to enough forage and therefore not good nutrition, they're being bombarded with a variety of pesticides. You know, it's not just one type of pesticide we're using in these areas, it's many types of pesticides, and that's not healthy for them, either, and it's going to make them more susceptible for the other threats that they're also being faced with, such as parasites and diseases.

REHMSo tell me what, Dennis, tell me what you think of the president's plan to help save the bees.

VANENGELSDORPWell, I think that it's a fairly well-balanced document, I think it's a good document, and it attacks the three big areas of concern. One is certainly varroa mite, this parasitic mite. It's like a vampire, and it bites bees, and it spits viruses into bees, and we think those viruses are evolving and becoming much more lethal. And we're seeing that these populations are changing in the fact that they're growing much quicker and spreading. So he's got a policy in place to try to give more tools to beekeepers in order to control varroa. That's really important.

REHMBut...

VANENGELSDORPThe big, exciting part is the land management. He's partnering with private-public partnerships to get a lot of landscape into good pollinator forage, and I think that's the big message. This can't be just government. It has to be everybody involved in making sure we have good, clean, year-round food for bees in our landscapes. And that's a big one, and I think that's good for everybody.

REHMThere's been a lot of finger pointing, though, at a class of pesticides referred to as neonics. Is that the correct pronunciation?

WALKERYeah, the neonicotinoids, or we call them neonics for short, correct.

REHMNeonics, tell me about that.

WALKERSure, well, neonics are, you know, a pretty concerning type of insecticide for bees, and there's three big reasons why they're problematic for bees and other pollinators. One is that they're systemic, so that means that they're actually taken up into the plant tissue when they're applied, whether as a spray or even as a seed coating, which is a new that we're using these chemicals. And that means that all parts of the plant are toxic to bees, including the pollen and nectar, which is not great for bees when they're feeding on these crops.

MS. BECKY LANGERTwo is that they're very persistent and mobile. So they can stick around in the soil for years after their application. And they're mobile in the environment. So we've found the contamination of groundwater, surface water and soils throughout the country, and that endangers countless species in those habitats.

WALKERAnd the third problem is their high toxicity. Neonics are very toxic to bees. Scientists have found that they're up to 10,000 times more toxic than other insecticides, like DDT, and that's a really big problem for bees not just in the short term, in terms of killing bees outright, but also there are now sub-lethal and chronic effects that we're aware of. And the impacts that these pesticides are having on bees when they're exposed to low doses over a long period of time are really concerning.

REHMJim, what's been your experience?

DOANWhat we've seen is where we're near corn in particular, we've seen high losses of bees, first with populations declining within those hives when the bees start gathering pollen around them, but we'd also seen, in the spring when corn is first planted, that we had hives that showed contamination from these neonicotinoids, and those hives would certainly be reduced in population, if not killed outright. And then we also experienced, and Dennis has this information actually, we had the highest level thiamethoxam, which is one of the big neonics, in the nation in our hives, and we were 39.6 parts per billion, which is more than enough to kill a beehive, and...

REHMAre you, or am I understanding correctly that you're saying that these neonicotinoids are more potent than DDT?

DOANYes.

WALKERYes, that's what some researchers have found, and, you know, when you -- when you consider that, on top of the just ways in which we're using them and how long they can stick around in the environment and accumulate over time, it's really concerning.

REHMWhat about the president's plan? How far does that go to satisfy your concerns?

WALKERWell, I think the fact that we have a national pollinator strategy is tremendous. It's really important that we raise the level of attention and awareness about this issue. Certainly bees can use all the help they can get right now, but the plan could have and should have gone farther with respect to addressing pesticide issues. Largely there's a lot of emphasis being placed on more research with pesticides. And I think there's a lot of research out there already that shows really alarming, you know, harms from the uses of these chemicals, and I think we have enough information to take action on these pesticides now.

REHMHow about you, Jim?

DOANI agree with Larissa that we've -- we've got enough data out there to show these products are a problem.

REHMAll right, and joining us now is Becky Langer. She is head of the bee Care Program for Bayer CropScience, one of the world's largest manufacturers of pesticides. Thanks for joining us, Becky. Tell us what you think of the pollinator plan.

LANGERWell, first off, thank you for inviting me to participate.

REHMCertainly.

LANGERAnd here at Bayer CropScience, we believe that the national pollinator plan is a balanced and very multifaceted approach for improving pollinator health, and that's great news because improving honeybee health, which they're facing today, is going to take a very concerted effort from all of the stakeholders, even the public. And so this strategy provides an excellent roadmap, if you will, for everyone to kind of follow and get on the same page.

REHMOf course there are many, many environmental groups that felt the plan did not go far enough on trying to limit pesticide use, and certainly you've heard from the beekeeper here, Jim Doan, you've heard from Larissa Walker. What are your thoughts there?

LANGERI think that the plan is really focused in on some key areas, the research, the forage and the education. And then it mentions statement management plans. This is a very important part and a very smart strategy because you can imagine that the problems that a corn grower in Iowa faces are going to be very different from a citrus farmer in Florida. So by allowing states to develop a management plan that's applicable for their situation and their growers and beekeepers that are coming in makes the most sense. It allows them to work together and create the communication, and communication is really going to be the key to some of the success factors.

REHMTell me how big a contributor pesticides are to the poor health outcomes of bees from your perspective.

LANGERSo pesticides, when used according to their label directions, can be safely used around pollinators. They have been found to not have a long-term effect on colony health. The critical component is using them according to the label and how they're intended to be used.

REHMIs that what you believe, Larissa?

WALKERI think a lot of beekeepers have already experienced problems with these pesticides when they are used according to the label. You know, the label is not taking into account how long these pesticides stick around in the environment. They're not taking into account all the other species that may encounter these pesticides besides just honeybees. And I think they're really nasty chemicals, and they're being used in ways that aren't even necessary right now. They're being greatly overused in this country, and that's very concerning considering all of the risks we know that come along with them.

REHMNow Becky, I gather you have some data from Australia that indicates that they're being used well.

LANGERYes, in Australia they use neonicotinoids as much as other countries, if not more, and they do not see the bee declines or the bee health issues that we see in the United States. A key connecting piece of information here is that Australia is one of the only places in the world that does not have the varroa mite, and I believe you've already talked a little bit about the varroa mite being such a key pest in the bees and injecting viruses that are really affecting the health.

LANGERSo when we look at that example, we don't have the varroa mite, but we have the neonics, and we have a healthy bee population.

REHMAnd you're listening to Diane Rehm Show. Jim Doan, how do you account for the differences that Becky is pointing out Australia with the use of these chemicals and what you're seeing here?

DOANWell, in Australia, for one thing, a lot of the beekeepers moved far away from the places where crops were being grown with neonics, and that was what helped them stave off this problem. And the other thing is, when you start adding multiple stresses onto bees, then you see more problems, and certainly if they don't have varroa in Australia, that's one less stress that they have to deal with, and so maybe the bees can survive in certain conditions, you know, through that. But it is not what we've been hearing in -- when we've been talking to Australian beekeepers.

REHMDennis, do you want to weigh in here?

VANENGELSDORPWell, I do think that the idea that we want to reduce how much pesticides are in the environment is a really important and no doubt that that will help bees. I do -- I am a little bit concerned about the focus on neonics. I think we have to make sure that we follow the data and make sure that we're looking broadly at the synergistic effects that happen between chemicals, certainly, and I think we just have to use wise policy when using pesticides. The fact is that the studies are out there. At real-world doses, neonics at real-world doses, aren't hurting honeybee colonies, probably a lot of the other pollinators but not honeybee colonies, and that's because honeybees are these social organisms that if you look at the colony as the living organism, it can lose 30 percent of its worker force and still survive.

VANENGELSDORPBut these combinations of different things, also the mixtures that the pesticides are mixed in, probably all have adverse effects and additive effects. So with mites and with poor nutrition, it all becomes worse.

REHMNow Becky, finally I understand that the EU, the European Union, has banned the use of these neonics. How has your company, Bayer, reacted to that decision?

LANGERWe have the information that the large-scale studies have shown that honeybee health correlates well with the parasites and the diseases and not the pesticides. Both the USDA and the EPA have stated in a joint report that it's a wide range of factors, as Dennis just mentioned. And so the EU ban is not a realistic approach to improving bee health, and in fact they have not seen a correlation of improving bee health since that ban went into place, and it's affected the farmers.

LANGERThey've have crops ravaged by the flea beetle because they have not been able to apply products. And so they're actually seeing some adverse consequences to this ban.

REHMLarissa?

WALKERWell, you know, the moratorium there has not been in place for long enough. I think that we could see some long-term improvements with pollinator health. As I mentioned, these are persistent chemicals, so we will need to give them some time to leave the environment and for bees to actually improve. But I also think it's important to point out that, you know, not all uses of neonics are benefitting farmers, as we've been told. One of the largest uses of neonics is as a coating on a variety of annual field crops, as a seed coating, such as corn and soybean, and that's a very concerning treatment.

REHMLarissa Walker. And Becky Langer, I want to thank you for joining us. She is head of the bee care program for Bayer CropScience. Thanks for joining us, Becky.

LANGERThank you.

REHMShort break, and we'll be right back.

REHMAnd welcome back. We're talking about bees, the kinds of death rates they are suffering. Over all, we've been told the overall population of bees around the world has not declined simply because beekeepers are able to establish other hives as soon as they see that one is dying. But the expense involved is pretty terrific. We've got lots of callers waiting. Let's go first to Bill in Baltimore, Md. You're on the air.

BILLHi, yes, I'm a treatment-free urban beekeeper in Baltimore, Md. Maryland has saw I think the fifth highest death of bee colonies in the nation this year. We were over 60%.

REHMWhoa.

BILLWhich is clearly way unsustainable. The first thing I'd like to try and address here is the studies done by industry on neonicotinoids, they do not use the same colonies in their studies from year to year. They actually replace colonies and start the studies over again, and/or the re-queen those colonies, which in a sense is basically showing that these studies are showing that these chemicals are highly problematic. The second point I'd like to make is, we no longer are focused on quality of queens and honeybees. We are mainly just, simply just trying to keep up with the quantity. We need such a large quantity of queens and colonies that these things are being replaced so often that, you know, again, the survival rate of these queens are inside of a year, whereas traditionally they were three, four, five years long. We no longer have that quality any longer.

REHMAll right. Larissa.

WALKERI think, you know, the fact that we know the Environmental Protection Agency relies quite heavily on industry data for a lot of their risk assessments when approving these pesticides is a problem, and especially when we know how much, you know, scientific literature is available out there now and how much research has been done, where there are adverse harms being shown to honeybees and other pollinators. We'd like to see those taken into account just as much as industry science.

REHMHow difficult is it to find new queens, Jim?

DOANIt's not difficult. The problem is that because there's such a high demand, you're having to wait to get queens quite often, because the queen breeders can't make queens fast enough for the need that's out there. And so if you want to order queens, you really need to almost -- a year in advance, go ahead and place your order.

REHMOh.

DOANBecause they're just -- there's not as many queen breeders as there once was, because they're having problems also, just like the commercial beekeepers, so are the queen breeders.

REHMHere's an email from Kathleen, who says, "Since Toronto has become a no-pesticide city, the urban beehive population has been shown to be healthier, have far fewer losses than the bee colonies located outside the city." Larissa?

WALKERI think that that's great and we've seen similar efforts happen across the country here in the U.S. There have been a number of cities that have adopted, you know, pesticide-free areas. Eugene, Oregon was the first to do this and we've seen this happen across the country since. And it's really important it's not just that they're going pesticide-free, but they're also creating safe havens for pollinators with planting pollinator, you know, friendly habitat. And it's really just making this a safe space for bees to exist in and have access to good nutrition and habitat, without being (word?) with pesticides.

REHMHere's another email from Alice, and Dennis, I wonder if you can address this. Becky said that pesticides are fine when they're used according to label, but Alice said "that being said, how common do you think it is that in the U.S., farmers misuse pesticides. How can we address that?"

VANENGELSDORPWell, I think that's a really good question, and I think that all farmers, especially those renting colonies to pollinate their crops, know enough not to spray pesticides on the flowering blooms. I don't think this is necessarily a farmer misapplication. We do have evidence that we are finding that when we put colonies in places that -- for pollination, that the pollen they're bringing back isn't necessarily the crop of interest. And so that's why we have to look at what these exposure roots are.

VANENGELSDORPWe certainly know that on average, every -- 80% of colonies in this country have at least three products in them. And so there's a lot of different chemicals in these colonies. And we have to understand the synergism. Again, though, it's not just about how toxic they are, it's how much of these products there are in the hives. And so just because you're able to detect it doesn't necessarily mean harm. We have to understand the complexity there. And certainly being healthy with good nutrition is gonna make it easier for you to detoxify, again, with these two. So it's a complicated problem and so it needs a complex but balanced approach.

REHMAll right, let's go to Moses Lake, Washington. Elliott, you're on the air.

ELLIOTTHi, Diane, I appreciate you taking my call.

REHMSurely.

ELLIOTTI'm a farmer in Moses Lake, I actually raise thousands of acres of seed crops, and so I rely on thousands of hives of honeybees, but we also use leaf cutter bees and alkali bees to pollinate our different crops. So it's obviously a topic of great concern to people in my industry, but I have two comments. One is, like the other people have said, pesticides are safe if they're used according to the label, and 99% of the time, they are. You know, when pesticides are put up for review or receive a label, they generally run tests to see the toxicity level for not only honeybees, but other actively foraging insects and beneficials.

ELLIOTTAnd so, you know, people following the label, it's not a problem. But we deal with a lot of beekeepers and I keep my own bees, and really the key to the whole thing is how you put them to bed for the winter. If you have an actively growing hive, with good reproduction, good nutrition, it's alive and well when you go put it away for the winter, when it's gonna go through that period where it slows down for the winter and stops really growing, you're gonna have good success. And we've actually had people out here put them into cold storage and controlled climates, and drop their losses down to less than 10%, which is great any year, even before colony collapse disorder made its appearance.

ELLIOTTSo there are ways to fight it, but it comes down to how well are the beekeepers keeping their bees. And if they're running them all over the country and stressing them out, and moving them too often and not feeding them well, they're gonna die.

REHMWhat do you think, Jim?

DOANWell, he is right about some things. It's taking care of bees, but I'm dumping into 1400 hives of bees, we fed almost 100,000 pounds of sugar this year. And so nutrition is not my issue, and we're feeding tons of protein also, because our bees are not getting the proper nutrition from the environment, so we're having to supplement.

REHMHere's another issue from Keith in Gainesville, Fla., who says, "Including the pesticides killing and weakening the bees, their overuse has increased the strength of the pests that survive and attack the bees. So just like the overuse of antibiotics, the pesticides have killed the weaker bee-killing parasites, leaving ever stronger parasites to attack the bees." Larissa.

WALKERWell, we definitely have a lot of research showing that exposure to pesticides can weaken the immune system of bees, and impair their detoxification systems. And that does leave them more susceptible to a variety of other threats that they face, such as the varroa mite, such as, you know, diseases like the Nosema virus, and that's a problem.

REHMI want to ask you all about the varroa mites. Dennis, they've been around, I gather, since the '80s, but the deaths of the bees didn't start spiking until eight years ago. So how significant an issue can these varroa mites be, unless, as our caller from Florida says, the mites themselves have grown stronger?

VANENGELSDORPWell, it's a really good question. And I think that there is a real legitimate debate. Do varroa mites kill bees or did the viruses they transmit kill bees? And so what we've seen before the varroa mite was introduced from Asia, over here, that there were viruses in bee populations that were benign and they weren't hurting the bees. But that was because the viruses got transmitted from mother to daughter.

VANENGELSDORPNow, we have the mite and the viruses are getting transmitted from sister to sister. And so just that evolution suggests that the viruses are going to evolve and become much more virulent. And so the virus complex has changed. And so what we see is that 20, 30 years ago you could tolerate populations of 20 mites per 100, that was the threshold. Now, that threshold is down to 3 mites per 100. Also, the chemicals that we have -- the beekeepers have to control these mites has really, really changed.

VANENGELSDORPA lot of these practices aren't working as well, and so that the mites have become resistant to some of our tools. So certainly the mite we're talking about now is different than the mite we had. I'm not sure it's agricultural pesticide related, though.

REHMWhat do you think, Jim?

DOANWell, certainly the mites, you know, we're seeing lower levels of mites are killing hives' bees with having parasites or, you know, viruses in the bees. But also you have to understand that when the hive has much lower population it doesn't take as many mite to kill that hive. And with the stresses that we're having out in the environment, the bees just cannot handle one more stress. And the mite population, as small as it is, has just as dramatic effect as 20 mites did in a 100, you know, 20 years ago.

REHMWhat about changes in the weather? How might that be affecting bees?

DOANWell, we certainly are seeing like this past spring it was extremely warm compared to what we normally experience in the Northeast. And that -- and so we're seeing that flowers bloomed much earlier than normal. The bees are on a certain time schedule. The flowers are on a different time schedule. And so the bees aren't ready, necessarily to work those flowers when they should have the best population to do that. And so that certainly has an effect.

DOANI just wanna make one point that I don't think, you know, we've heard Bayer say properly used chemicals. The problem is only about 10 to 20 percent of these materials are actually being sprayed and mixed by farmers. The rest of it is already made up by the chemical company, applied to the seed and put out in the environment. And I think that's a strong point that needs to be made, that it's not the farmers that are overdosing pesticides out in the environment. It's the chemical companies and the seed treatment companies that are putting all these products out in the market.

REHMWhat do you say to that, Dennis?

VANENGELSDORPWell, I haven't heard that statistic. I certainly think that there is a lot of room for wiser use. It seems silly to me that 99 percent of the corn in the country is treated with neonics, but clearly there is some advantage there. And so we have to move away from this prophylactic treatment to a treatment by need. And…

REHMBut…

VANENGELSDORP…I think that that's true.

REHMI just have to ask, if we banned DDT and these neonics are said to be stronger than DDT, has there been a move to ban the neonics?

WALKERThere's not been a move here in the U.S. by the Environmental Protection Agency to ban them. I think the EPA has said that they're looking for more research about these, you know, synergistic affects and, you know, everything that's affecting bees. There has been an effort recently by the EPA to prohibit spray applications of these pesticides in an areas when beekeepers have their hives on those grounds for contracted pollination services.

WALKERBut that's really only protecting bees in that area. And bees don't like to stay confined to one area. And this is really only an effort to protect honey bees. We're neglecting then the impacts of these pesticides to thousands of other species of wild bees in the U.S.

REHMAnd you're listening to ""The Diane Rehm Show." Let's go to Gaye, in Cadiz, Ky. You're on the air.

GAYEYes, ma'am. Thank you. I have two points, actually. The first one is that -- I told the screener. I have heard on the news of three semi-trucks loaded with bees, 60 million bees per truck and they crashed. One in Las Vegas, one in Colorado and the most recent one was in New Jersey. The beekeepers are called in, but eventually they were all euthanized with some sort of foam spray. Why aren't these trucks being escorted through cities just like house trailers are?

GAYENumber two, these -- you hear about eat beef that's grass fed. Well, that's all these pastures are is grass. There's no weeds allowed out there. There are sprays. I have a field across the road from me and they spray in the springtime and then a couple times during the year. They also go through and mow down any kind of weeds that have the temerity to grow in that field. So -- and then they also spray Roundup on the fence lines, so that eliminates all the weeds that these bees could be feeding on.

GAYEI have five apple trees and two pear trees. And this year was the first time I had honeybees show up. When an Amish neighbor moved in, he said he had a beehive with him. All I've had to depend on the other pollinators, the bumblebees and the wasps and stuff.

DOANI just wanna say that, you know, as far as the crashes of bees that there's hundreds of thousands of loads of bees that travel all over this country. And unfortunately, you know, we try not to have any accidents, but, you know, transportation is an issue that we all have. But overall the bee industry is safe about moving bees and that. And certainly I'm glad that you got some Amish beekeeper that's next door.

REHMYeah.

DOANAnd we certainly -- we promote people wanting to keep bees.

REHMEncouraging small…

DOANExactly.

REHM…homeowners, too.

DOANThat's right. Everyone should have a hive or two of bees.

REHMDo you wanna comment on that quickly, Dennis?

VANENGELSDORPYes. No. And I think that the one point that was -- is that we have to reexamine why we think the green lawn is beautiful. Why don't we have our lawns full of flowering plants? Some people call them weeds, but they're bee food. And so we have to reconsider what we think is beautiful because that's the core. We all can play a role. Pollinator gardens and let's have flowering yards.

REHMYou agree, Larissa?

WALKERAbsolutely. More habitat, but let's make sure that that habitat is pesticide free so it's truly a safe haven for bees.

REHMSo do you see the EPA at least beginning to examine neonics? And she mentioned Roundup. Is that one of the neonics?

WALKERNo. Roundup is an herbicide. So neonics are insecticides. Obviously, they're gonna be toxic to insects like bees. And Roundup is the most widely herbicide in the world. The key chemical in it is glyphosate and that's really been a big issue for monarch butterflies because glyphosate has virtually eradicated milkweed plants in corn and soybean fields.

REHMMilkweed, one of my favorite plants. Well, I want to thank you all. It's been a most interesting discussion. Jim Doan, he's a beekeeper, owner/operator of Doan Family Farms. Larissa Walker and Dennis vanEngelsdorp. Thank you all. And thanks for listening. I'm Diane Rehm.