USDA study concludes neonics not driving bee deaths—As White House set to announce pollinator revival plan’

Even as a special White House created task force is poised any day now to address concerns over supposedly vanishing honeybees, new research suggests that the very premise of the federal investigation may be misplaced.

Last summer, President Obama asked the Environmental Protection Agency to investigate conflicting reports that pesticides, and in particular a class of chemicals known as neonicotinoids, were the probable cause of mysterious bee deaths and declining numbers of beehives.

The latest headline on farmers’ critical pollinator? The numbers of beehives are actually growing, continuing a multi-year improvement—gradually repairing the damage wrought by the 2006 mass bee die off known as Colony Collapse Disorder.

The Department of Agriculture announced late last week that honey production, which had been disrupted after CCD devastated the bee population nine years ago, continues to improve, up 14 percent. The total number of hives also increased again, by 100,000 or 4 percent, as it had increased the year before and the year before that.

More to the point as to the acrimonious debate over whether and how much neonicotinoids are impacting bee health, the total number of beehives today is higher than it was in 1995 when neonics as they are often called had just come on the market.

The report also comes just days after a USDA-sponsored study concluded that widely promoted claims that neonics are the primary driver of been health problems seriously distort the scientific explanation as to why bees have struggled over the past decade.

Simple or ‘simplistic’ explanations for bee deaths?

Here are the data for the number of managed beehives in North America, showing the stabilizing situation even before last week’s 4 percent increase:

Screen Shot 2015-03-22 at 5.17.37 PM
Sources: USDA and Statistics Canada

After a rocky few years as the CCD crisis unfolded, beehive numbers stabilized and then began a gradual improvement—and now stand at 20-year highs in North America and worldwide.

The eruption of CCD and the subsequent fall-off in over wintering bee hive counts has prompted understandable and justifiable concern. But–while mainstream scientists warned against politicizing a complex and developing situation, advocacy groups coalesced around one rather simple—entomologists called it simplistic—explanation: bee deaths were caused by the growing use of neonics.

Neonicotinoids are a class of insecticides introduced in the 1990s precisely because they were thought to be less harmful to beneficial insects and humans than the aging chemicals they gradually came to replace. They are most often used by farmers who coat them on seeds, which then grow into plants that systemically fight pests.

Even as the CCD’s concerns faded—scientists now believe it was a short-lived phenomenon that has occurred numerous times over the past few centuries—environmental groups continued to post thousands of blogs and stories citing one out-of-context study or another as the ‘definitive’ explanation for a mystery that most mainstream experts say is complex and not easily reducible to the kind of black hat/white hat kind of narrative that so appeals to advocacy groups.

The real cause of bee health problems is gradually coming into sharper focus. In the latest in a string of studies looking at the relationship of pesticides found in pollen to honey bee colony health, independent researchers, publishing in PLOS ONE, politely slammed many past studies that hyped pesticides, neonics in particular, as the likely driving cause of CCD.

The scientists—all independent and working in a cooperative agreement with the USDA-ARS Bee Research Laboratoryfound that many past researchers often based their experiments on extremely high amounts of pesticides—far more than a bee would normally encounter in its life. They looked instead at field realistic doses of pesticides, although always testing at the high end of what bees might actually experience.

They deliberately fed honeybee colonies the neonic pesticide imidacloprid in a dose-response experiment based on real-world pesticide levels: 5 and 20 µg/kg doses are in the reported high range of residues present in pollen and nectar in seed-treated crops. They also included a 100 µg/kg dose as a worst-case exposure level, representing imacloprid applied to flowering crops. (That level caused a large kill of bumblebees in a 2013 Oregon incident.) Bee exposure occurred over nearly three weeks, longer than bees are usually exposed to neonics, so they they could not be accused of under-dosing them.

What did they find? Even at the highest dose of pesticide exposure, the researchers found no difference in the performance of the treated and untreated hives. They found no evidence that imidacloprid affected foraging activity during and after exposure in their experiments.

Directly contradicting claims by advocacy groups whose complaints prompted the forming of the White House task force, the longer the time period the less pesticides were found. “Bee Death Study Clears Bayer’s Insecticide as Sole Cause [of CCD],” concluded Bloomberg in its summary analysis. “A widely used insecticide developed by Bayer AG and tied to deaths of honeybees isn’t the main cause of the fatalities, University of Maryland researchers said in a study that may weaken arguments used by environmentalists seeking to ban the chemical.”

Chensheng Lu’s conclusions discredited

The new study can also be seen as a direct rebuke of the controversial research by Chensheng Lu, a Harvard University environmental scientist who used doses 10-100 times higher than found in the real world to support his claim, accounted before the embarked on his research project, that neonics were the driving cause of CCD.

Lu reached folk hero status among environmentalists last May after the Harvard School of Public Health launched a promotional campaign touting his latest, controversial research: “Study strengthens link between neonicotinoids and collapse of honey bee colonies,” a press release claimed.

News of the “definitive” study exploded on the Internet. Many environmental and tabloid journalists painted an alarmist picture based on Lu’s research: “New Harvard Study Proves Why The Bees Are All Disappearing,” “Harvard University scientists have proved that two widely used neonicotinoids harm honeybee colonies,” and “Neonicotinoid Insecticide Impairs Winterization Leading to Bee Colony Collapse: Harvard Study” are typical examples of hundreds of blog posts.

Scientists now say that the Lu study, published in an obscure pay for play journal, proved only that feeding bees poisonous levels of an insecticide can and will kill them. University of Illinois Department of Entomology Chair May Berenbaum, who headed up the National Academy of Sciences 2007 National Research Council study on the Status of Pollinators in North America, has called Lu’s research “effectively worthless” to serious researchers.

The experimental design and statistical analysis are just not reliable. … He never tested for the presence of pathogens, so his conclusions dismissing other likely causes don’t follow from his data. The whole study just doesn’t hold together. And I’m not being a fusspot here. It’s unfortunate this was presented as a Harvard paper because it gives this credibility that it doesn’t deserve.

Ideology driving federal response?

The buzz that followed the publication of Lu’s 2014 study is a classic example of how dicey science can combine with sloppy reporting to create a ‘false narrative’—a storyline with a strong bias that is at once compelling and wrong. The Lu study was a scientific outlier, albeit one that fit the prejudices of advocacy groups. The eager embrace and promotion of this fatally flawed research illustrates how simplistic ideas get rooted in the public consciousness. And it shows how ideology-driven science threatens to wreak public policy havoc.

Lu is on the board of The Organic Center, an arm of the multi-million dollar Organic Trade Association, a lobby group with strong financial interest in disparaging conventional agriculture, synthetic pesticides and neonics in particular—a conflict of interest that Lu never acknowledges and to my knowledge no other journalist has reported.

Related article:  Talking Biotech: Benefits and unanticipated consequences of neonicotinoid insecticide use

This latest USDA guided study goes along way to reversing the misinformation that has rippled forth in the year since the Lu “solved” the bee death mystery. Are there any prominent entomologists who endorse Lu’s alarmist findings? I couldn’t find any in months of trying.

A Mother Jones article by controversial activist-journalist Tom Philpott suggesting the Lu had all but solved the mystery of bee deaths quoted Jeffrey Pettis, an entomologist and research leader at USDA’s Beltsville’s Bee Laboratory, as appearing to be supportive. “Pettis told me that he thought Lu’s study ‘adds to the list’ of studies showing that pesticides pose a significant threat to honeybees,” he wrote. I emailed Pettis about that quote:

I was trying to be diplomatic when I talked to Philpott but the Lu study should not have been published. It is not good science. I was trying to say that it adds to the list that pesticides and bees don’t mix but it is not a paper that shows that neonics cause problems simply because it was poorly replicated with high dosages used.

Pettis is one of the authors of this latest, far more sober and professionally researched, analysis. The Maryland researchers did acknowledge that neonics are not exactly harmless, but they are far down the list of health challenges faced by bees.

“It contributes, but there is a bigger picture,” they said in a news release. Other factors are thought to include parasites such as Varroa mites and Nosema fungus, a bacterial disease known as foulbrood, viruses, drought and loss of habitat.

Even more surprising, said Pettis and his colleagues, over the course of the experiment, pesticide residues declined, eventually becoming non-detectable within colonies’ beebread and honey. As Wired noted in its analysis, that’s one of the things that makes imidacloprid so popular, as the pesticide is designed to break down quickly. In fact, in one of the three years more “queen events,” or creation of special queen cells, were found in the treated colonies. And while colony overwintering survival did seem to be linked to high doses of the pesticide in one year, the link collapsed the following year. There was no consistent pattern suggesting reports of harm were anything more than random data noise.

“It’s not surprising that higher levels will hurt insects,” said Dennis vanEngelsdorp, a leading bee researcher often credited with identifying and naming the 2006 CCD event. He was not involved in this study. “They’re insecticides after all,” he added. “But this study is saying that neonicotinoids probably aren’t the sole culprit at lower, real-world doses.”

That’s consistent with mixed results of many other experiments with these pesticides. vanEngelsdorp, said. In general, pesticides don’t kill bees, but they can make other bee problems worse.

But even that statement needs to be put in context. All farming requires tradeoffs and risks. Best practices require striking a reasonable balance between costs and benefits. Farmers necessarily use pesticides; even organic farmers use them, extensively. And all pesticides, even organic ones, result in some collateral damage—the killing of some beneficial insects.

The most honest and realistic question therefore becomes: Which pesticides yield the most benefits to farmers while causing the least harm to the environment, including in this case, bees? Demands to neonics because they are ‘part of the problem’ make no reasonable sense, as all pesticides are part of the problem.

Real world impact of ban

If the U.S. government moves to restrict the use of neonics, what would replace them? In Europe, where neonics were banned 15 months ago after a ferocious lobbying campaign by activists, farmers have begun replacing them with older pesticides phased out years ago precisely because they caused too much collateral damage. So the panic solution—an open-ended moratorium on the use of neonics—has actually led to increased bee deaths.

The impact on farm production of the European ban is also coming into sharper focus, and the picture is ugly. Neonics are used most commonly on rapeseed, more commonly known in North America as canola. It’s used primarily to make oil. While rapeseed production has reached record levels in the United States and Western Canada, in places where honeybee hive numbers are hitting record levels, Europe’s farms are in disarray. Figures released earlier this month by European farmer cooperatives reveal regional rapeseed production is expected to fall by as much as 7 percent this year, compared to 2014.

“The situation is very serious, with declines of up to one million tons in rapeseed production estimated in Germany. Some areas have been particularly badly hit, like in parts of the UK where producers lost 40 percent of their production,” said Arnaud Rousseau, chairman of the oilseeds working group.

Why the sharp drop off?

“What makes it worse is that there are no alternative tools [replacing neonics] for crop protection for the spring varieties and crops are being destroyed by flea beetle attacks.”

This confirms anecdotal reports that have been mounting for months. As Matt Ridley reported last fall in The Times of London:

All across southeast Britain this autumn, crops of oilseed rape are dying because of infestation by flea beetles. The direct cause of the problem is the two-year ban on pesticides called neonicotinoids brought in by the EU over British objections at the tail end of last year. … Farmers in Germany, the EU’s largest producer of rape, are also reporting widespread damage. Since rape is one of the main flower crops, providing huge amounts of pollen and nectar for bees, this will hurt wild bee numbers as well as farmers’ livelihoods.

The EU farmers cooperative has called on the EU Commission to do a socio-economic impact assessment to look at the extent of the damage.

As the harmful consequences of the precipitous European moratorium deepen, all eyes are turning to Washington. Activists have been trying to jack up political pressure in the United States, just as the surge in bee deaths in the US and Europe appears to have reversed. Last September, a coalition of environmental groups co-wrote a letter signed by 60 Congressional Democrats urging the EPA to restrict neonicotinoid use citing Lu’s work in arguing that “native pollinators” have “suffered alarming declines.”

What’s next? The White House pollinator task force is set to issue its evaluation of the honeybee health “crisis” any day now, and it may include calls to further restrict the use of neonics.

Here’s the nuanced reality: The uncomfortably high number of bee deaths eludes the kind of definitive but reckless calls for action that could result in precipitous regulations. Science is not a set of results; it is a method. If the method is faulty, as in the case of the Lu study and the simplistic ‘neonics causes bee deaths meme’, the results are useless.

“This is a really complex issue with no quick and easy solutions,” May Berenbaum told me. These papers simplistically fingering neonics are” just not good science.”

Jon Entine, executive director of the Genetic Literacy Project, is a senior fellow at the World Food Center Institute for Food and Agricultural Literacy, University of California-Davis. Follow Jon Entine on Twitter @JonEntine

66 thoughts on “USDA study concludes neonics not driving bee deaths—As White House set to announce pollinator revival plan’”

  1. I would like to comment on the USDA study published by Dively et al. Your statement that “Even at the highest dose of pesticide exposure, the researchers found no difference in the performance of the treated and untreated hives. None.” grossly misrepresents the findings of the paper referred to (

    While they indeed find no significant effects on foraging activity, they do find significant effects on colony health and survival such as:

    “However, Varroa infestations did show a significant dose response in both years, and the 100 μg/kg treated colonies in 2009 had statistically higher mite counts compared to counts in control colonies.”


    “Of the 2010 colonies that did survived to October, most imidacloprid-exposed colonies had numerically fewer bees and less brood, beebread and honey going into the winter.100, 94.1, 82.4 and 82.4% of the colonies in the control, 5, 20 and 100 μg/kg treatment groups, respectively, survived to the last inspection in October. Although not statistically significant, this overall dose-dependent response strongly suggests that the higher imidacloprid doses had delayed sublethal effects on colony health.”

    as well as their most striking finding:

    “Pooled over both years, colony survival in March averaged 82.4, 58.8, 47.1 and 52.9% in the control, 5, 20 and 100 μg/kg treatment groups, respectively”

    their conservative conclusion from this data is merely:

    “Given the weight of evidence presented here, we conclude that chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg) in the pollen of certain treated crops could contribute to reduced overwintering success but the most likely encountered field doses of 5 μg/kg, especially relevant for seed-treated crops, have negligible effects on honey bee colony health.”

    While the use of neonicotinoids can certainly not explain the observed patterns of colony collapse by itself (in fact, the authors of this study note that the symptoms of the lost imidacloprid-treated hives did not match CCD), we do not have sufficient evidence to rule it out as a contributing factor in this complex issue.

    • It is articles like this that causes disaster for wildlife, habitat, the world’s food chain, and mankind. It doesn’t even take a scientist to figure out that poison is never has been or never will be a problem solver. To work against nature instead of with nature has historically been a huge mistake, and humans like this author seem to keep making the same mistake over and over again. Sorry, sir, but poison, no matter how you engineer it, is not selective and affects more than the bees, it also affects you, too. When they die, so do you!

      • This isn’t a rational response. Scientists and others who base important decisions on data rather than emotion and narrative would be the last to say “poison never has been and never will be a problem solver”. “Poison” in the form of pesticides, for farming and other purposes, has solved an extraordinary number of problems over many years.

        As the article makes clear, there is a balance of risk to be managed. With increased scientific and consumer focus on the unwanted side-effects of pesticides, that balance is shifting and producing changes in both the way they are applied and in the formulations used. That’s progress. An unbalanced response like a moratorium on tha poisonz would just unacceptably increase the *other* risks to the food chain.

        • Ur just the latest soon to be debunked pseudo science advocate. Lead is fine. Tobacco is fine. PCBs and Dioxin are fine. U apologists with extremely short memories are so funny. In twenty years we will be ridiculing people like u. Science is on our side idiot. Money is on urs.

  2. “The buzz that followed the publication of [Divelly’s 2015] study is a classic
    example of how dicey science can combine with sloppy reporting to create
    a ‘false narrative’—a storyline with a strong bias that is at once
    compelling and wrong. It illustrates how simplistic ideas get rooted in
    the public consciousness. And it shows how ideology-driven science
    threatens to wreak public policy havoc.”

    I’ll be looking for this paragraph to be repeated with the corrected study reference in more reputable media sources in the not-too-distant future. Did you even read the study on which you apparently based your article? The results, as correctly described by Peter Emmrich in a previous comment, bear little resemblance at all to the press release, subtitled:

    “Field-based study shows honey bee colonies are not harmed by realistic levels of exposure to the world’s most common insecticide”

    The results show little difference in all kinds of details like bees per colony, brood ratio, etc. The one difference that’s shown is the one difference that matters:


  3. A typo I think
    “Demands to ban bees because they are ‘part of the problem’ make no reasonable sense, as all pesticides are part of the problem.”

      • Damn bees r all islamofascist woman-raping homosexual atheistic terrorists posing as “insects” anyway. Just like their human “supporters.”

        Kill them all, praise Jesus. God bless America. Better off without “pollination” and “honey.” That shit just gets in the way of God’s corn syrup.

  4. Good work, Jon. Only if you had done any research whatsoever you’d know that U.S. keepers began importing Australian honey bees in massive amounts due to Colony Collapse Disorder in 2007 and the numbers have steadily increased because of that save for a few die-offs over the past few years.

    This is, as usual, a misleading headline and a misleading article.

    • If you had done your research genius you would know that illegal importation of bees and bee products were implicated in bringing new pathogens into the US. These pathogens, along with the acaricides beekeepers use in hives were just two of several factors scientists think were exacerbating conditions leading to CCD.

  5. Is the number of colonies/hives the best measure to visualise the impact of CCD? For all I’ve heard about the disaster, beemageddon, etc. it neither appears to have been a catastrophic effect in 2006 (more like a slow decline over the preceding 10 years), nor quite as devastating as most people imagine: looks like a ~10% decline, or maybe a bit more. Or at least that’s the picture according to the number of hives measure: is it a fair choice of observable?

    • I would also like to see a bee expert chime in on the ‘total number of hives’. It seems like number of hives would need to increase if the density of bees per colony was decreasing due to higher worker mortality and hence, honey output, pollinator services would also decrease, necessitating more colonies.

  6. Hi Jon, nice article. But I recall that there was some apparently reasonable criticism of Matt Ridley’s Times article on the impact of the EU neonic ban on English rapeseed crops, and that the final count of the decline might be much less than suggested (albeit after requiring a large-scale replanting, which is hardly cost free).

    But these competing points have been made by advocates for policy positions, and hence it’s very hard to know what’s actually going on: is there an objective report of the cost impact of the ban and/or environmental impact of the switch to older pesticides?

    On potentially biased sources of data, *predictions* for 2015 from European farmer cooperatives don’t obviously sound to me like a robust or objective source of information either! But maybe I’m too pessimistic.

    • Hi Andy, you are right. Most of the claims of problems have been anecdotal, and they are coming from farmers who are miffed/angry that one of their pesticide tools has been taken away. The recent information from the farmers cooperative is more credible but a truly independent evaluation has not yet been made to my knowledge. We will continue to monitor.

  7. Jon, Your article headline, too, is misleading and does not include all the facts. In addition to the complex effects of neonics on insects there is also the question of the adverse health effects of neonics and the chemical residuals found in honey and plants for humans and other animals. Also of concern is the increasing admixtures of various pesticides on our fruits, vegetables, and ground water. Isolating one chemical to study in nature is now no longer possible due to the multiple pesticides currently in use.
    Although it’s always reasonable to look at both sides of an issue, this is not a balanced look as you claim.

    • I have talked to the two beekeepers that put hives up on our neonic treated canola fields every year and even they have zero concerns about the neonics harming their bees. The chemical only controls flea Beatles for about two weeks and you expect it to harm Bees three months later when the canola is flowering. Give your head a shake. I’m pretty sure if it did the beekeepers wouldn’t purpously put their hives in our canola fields.

  8. Even the abstract of the paper contradicts what this article says :/
    ” Analysis of colony survival data showed a significant dose effect, and all contrast tests comparing survival between control and treatment groups were significant, except for colonies exposed to 5 μg/kg. Given the weight of evidence, chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg) in pollen of certain treated crops could cause negative impacts on honey bee colony health and reduced overwintering success, but the most likely encountered high range of field doses relevant for seed-treated crops (5 μg/kg) had negligible effects on colony health and are unlikely a sole cause of colony declines.”
    Also, a working link for the article:

    • Read it again, RoroG:

      “Given the weight of evidence, chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg) in pollen of certain treated crops could cause negative impacts on honey bee colony health and reduced overwintering success”

      There are a LOT of qualifiers there. Do they indicate what percentage of the planted acres in the US receive these higher application rates? If the application rate is considered ‘high’ I doubt very seriously that a significant percentage of the acres in the US receive this level of treatment.

      “but the most likely encountered high range of field doses relevant for seed-treated crops (5 μg/kg) had negligible effects on colony health and are unlikely a sole cause of colony declines.”

      So… like the blog post above says, the effect is *negligible.*

  9. Neonics have only been around for a couple of decades, but annual
    global sales now top $2.6 billion. They were initially embraced because
    they are less directly toxic to humans than older pesticides and are
    effective at low levels, reducing the volume used. They can be applied
    to seeds and are absorbed into the plant, which then becomes toxic to
    insect pests, reducing the need to spray.

    We now know these characteristics are the problem. These chemicals are nerve poisons
    that are toxic even at very low doses and persist in plants and the
    environment. They affect the information-processing abilities of
    invertebrates, including some of our most important pollinators.

    Bees have borne the brunt of our unfortunate, uncontrolled experiment
    with neonics. Beekeepers report unusually high bee death rates in
    recent years, particularly in corn-growing areas of Ontario and Quebec.
    Virtually all corn and about 60 percent of soybean seeds planted in
    Ontario are treated with neonics. A federal Pest Management Regulatory Agency investigation concluded that planting neonic-treated seeds contributed to the bee die-offs.

    Europe reached a similar conclusion and placed a moratorium on the use of neonics on bee-attractive crops, which took effect last year.

    Critics emphasize that other factors—including climate change,
    habitat loss and disease—affect pollinator health. But these factors are
    not entirely independent; for example, chronic exposure to neonics may
    increase vulnerability to disease. A comprehensive pollinator health
    action plan should address all these factors, and scaling back the use
    of neonics is a good place to start.

    Apart from the immediate and lethal effects on bees, neonics
    represent a more subtle threat to a wide range of species. The 2014 Worldwide Integrated Assessment
    of the Impacts of Systemic Pesticides, the most comprehensive review of
    the scientific literature on neonics, pointed to effects on smell and
    memory, reproduction, feeding behaviour, flight and ability to fight
    disease. Jean‐Marc Bonmatin, one of the lead authors, summarized the conclusions:

    • U mean nerve disrupters and estrogen mimickers even at chronic low doses are NOT good to digest? Say it ‘ain’t so. Surprise surprise. I mean I thought the ego and brain size of these highly paid ‘scientists’ was enough to prevent any negative repercussions of these toxins.

      • You both forget that these are insecticides, they are meant to kill insects, and they do a very good job of it, with little risk to humans and other mammals.

        John conveniently failed to mention that one of the main reasons for neonics’ popularity is that they reduce the need for foliar applications of insecticides, which are KNOWN to directly cause bee deaths. In your attempt to villify scientists, farmers, and neonics, you let your bias show clearly.

  10. This report is junk. Independent scientists have consistently linked neonicotinoids to not only reducing the number of Queen’s produced by Bumblebees, but to affecting their ability to learn how to pollinate flowers and most importantly how to navigate their way back to the nest.

        • You mean where it says this:
          “Bumblebee (B. terrestris) colonies were placed adjacent to single oilseed rape fields grown from seeds that were treated with clothianidin, imidacloprid or had no insecticidal seed treatment. No relationship between the oilseed rape treatment and insecticide residues was observed, presumably because the bees were foraging over spatial scales larger than a field. Insecticide residues varied among colonies and
          the authors reported no evidence of a correlation with colony performance”

          That doesn’t support your claim, now does it?

          • Wow what an amazing bit of selective reading!

            This is a paragraph describing the conclusions of the original flawed analysis, it is not the conclusions of the actual paper you quote that reanalyses the data and concludes” It strongly suggests that wild bumblebee colonies in farmland can be
            expected to be adversely affected by exposure to neonicotinoids.”

            Incidentally there was no relationship between posticide treatment and insecticide residues because there was extensive environmental contamination on all fields, including the control.

          • Speaking of selective reading, what really chaps my backside is people that have zero agricultural knowledge quoting iffy studies.

            Some doofus landscaper sprays flowering trees, kills a bunch of bumblebees and all of a sudden neonics are like loose nukes.

            But since you’re so smart, how about you tell me what hazard I present to bees when I plant corn treated with a neonic like Poncho 500?

            Poncho 500 works out to 1.25 mg/kernel. A dent corn plant at VT growth stage has an above ground dry mass of about 1 lb. Conservatively, the below-ground dry mass is going to be around 12 oz.

            16 oz. + 12 oz = 28 oz. Convert to grams, and that’s 795 grams. Which is 795,000 mg.

            1.25 mg/795,000 mg = 1.57 ug/g. How is a pollinator of any kind going to be exposed to a hazardous amount of neonic at that that concentration?

            And the above assumes that the neonic is going to be evenly distributed over the mass of the corn plant. I don’t think it will, since the pericarb of the corn seed is relatively impermeable. But let’s pretend, just for fun.

            Then think about the actual pollen-generating structure of a corn plant. The anthers in a tassel only open up under specific conditions. So the bees have to be right there when the anthers open up.

            And we have the fact that corn plants aren’t really that attractive to bees in the first place, since corn plants don’t generate nectar.

            So, I’ll be crude and say that I think you are full of crap.

          • It is impossible to work out the exact risk to bees on a field by field basis. Factors such as how much of the active is washed into the soil before being absorbed, how much is absorbed from the residues in the soil and indeed the extent to which the active is concentrated or diluted in the pollen depends on corn variety, soil type and weather.

            Taking your calculation at face value (I thought it was Poncho1250 that is applied at 1.25mg/kernel, but happy to be corrected) and going back to the paper you just quoted you will note that 1.57ng/g (corrected from your ug/g) is still five times higher than the 0.3ng/g(=ppb) of clothianidin that appears to have caused reduced bumblebee queen production in the field study

            These chemicals are capable of causing debilitating sub-lethal effects at very low levels indeed.

            Bees are surprisingly fond of corn pollen. In fact scientific studies suggest it is their favourite – see the table in this paper –

            Not constipated, but thanks for your concern.

          • JoeFarmer’s calculation and units are correct (ug/g or micrograms/gram). But the typical amount of neonic found in corn pollen is usually in the nano (ppb) range, as this paper indicates.

            Matt, the clothianidin value of .3ppb you cited is from nectar not pollen, so it would not be applicable to corn. The paper you cited shows thiamethoxam causing reduced queen production above 1ppb. But it also says that other things besides pesticides can affect queen production, as seen by the variation at lower amounts of neonics.

            As to the claim that bees are fond of corn pollen, the table you reference just shows how often corn was in the top 5 pollen sources. That does not necessarily show preference, it could just as easily be due to prevalence. Everything I have read previously indicates that corn is not an especially preferred source of pollen for bees.

            I guess the thing that is most convincing to me that neonics are not the main cause of bee deaths, is that in western Canada canola production, which uses neonics and provides both nectar and pollen to bees, there have not been the problems with bee deaths that have occurred in areas with varroa mites.

          • Oh yes, my apologies, 1.57ug/g is so high it is in the fatal rather than sub-lethal range for bees, and well out of the range usually found in pollen and nectar – guttation fluid and dust much higher of course.

            You are quite right that the preferences of bees have not been fully illuminated and the graph is one of frequency of use. However, some grasses have abundant pollen and are routinely used with vigour by bees. In rice growing areas that is often the commonest pollen used. A plant does not need gaudy flowers to attract bees. I imagine that maize is not the commonest NAmerican plant, so some preference is likely.

            Death is not the only problem for bees, fecundity, queen production and overwintering success are all important. In terms of effects on wild bees Varroa is not an issue, although there are other relevant parasites (and of course habitat loss is disastrous). And we know that the factors interact – starvation, disease and pollution go hand in hand.

            I frequently encounter the view that people should not claim that neonics are the only problem that pollinators face, I am not sure I have ever encountered anyone actually arguing that neonics are the only casue of pollinator declines.

            The evidence is clear, neonics are one of the main problems that pollinators face. If someone has two potentially fatal diseases you treat them both, don’t you?

          • That bumblebee kill was due to an idiot landscaper spraying flowering trees. It has nothing to do with ag use of neonics.

            People like you don’t care to take the time to learn about a subject. And you just proved it by posting those links.

          • The bee death incident in Portland undoubtedly happened, it was reported in such main stream places as the Portland newspaper that this article itself links too. But JoeFarmer is right, that was a single applicator applying in a manner that is specifically against label regulations. Using that event as a basis for lobbying for a ban on this class of chemicals is akin to seeking a ban on water because it’s the leading cause of drowning. If the substances in question are used in a manner that is consistent with label requirements then the Oregon incident doesn’t happen.

          • You realise that Bumblebees and Solitary Bees pollinate the vast majority of all insect pollinated crops? If they die, agricultural costs will soar. I am talking by magnitudes of 100s or even 1000s.

          • That is a gigantic if, and there’s zero evidence that it’s actually happening. It’s not news that insecticides kill insects. The important thing to study is whether real world level of pesticides affect bees negatively. There’s also zero evidence that this is the case. Dr. Lu’s study at Harvard is a joke. Everything else is just speculation, like the link you gave me above. “If”, “might”, “maybe”- those words should set off you’re sensor that you’re reading pseudoscience.

          • I have to laugh with disbelief. haha, how much independent scientific evidence do you want? There’s a tranch of robust, independent scientific evidence that proves how harmful neonicotinoids are to pollinators. It does the industry no credit to continue to seal up the stable when the horse has already bolted. It is ridiculous.

            I am always happy to debate in good faith, but there’s no ‘if’ any more. Independent studies are consistently proving the major concerns of farmers and environmentalists together. Yet, the industry refuses to even consider the possibility of danger which is what makes their position all the more ludicrous. Let me put it in a way everyone can understand the yields will drop off a cliff if the pollinators die, much worse than if their is a plague of locusts every year muching on crops for the rest of time!

          • Well, that depends on the crop, and crops like almonds will suffer immensely if there are no pollinators. But, here in the US, we have more honey bees (our chief almond pollinator) than ever before. Despite the rampant use of neonics. Again, there is no evidence that bees are being impacted at real world levels, just as there is no evidence that neonics are the primary cause of CCD. Lab studies only reinforce what we already know, insects are vulnerable to insecticide. Isn’t that the point of insecticides? You don’t have to convince me that been can be killed by neonics, I’m well aware of that. The problem for you is this: they aren’t being killed by neonics in the real world.

          • Honeybees? You realise that studies consistently show that honeybees are less efficient, less reliable and less diverse than wild bees such as Bumblebees. Nor will honeybees pollinate some crops that Bumblebees will e.g. Tomatoes.

            Regarding the other issue about lab tests. The study I referred to above (reported in the Independent) is about a study, a field test that took place in sweden that was published this week. Neonicotinoids were lethal to Bumblebees. Have another look.

          • You’re selectively reading what I wrote. I never said honeybees were primary or even efficient pollinators. I’m a botanist, I fully understand the role of pollinators and their importance to plants.

            As to your link to the independent, where in your link did it specifically say that neonics were toxic to bees? The solitary bees didn’t nest next to treated fields, the bumble bee colonies didn’t grow, but did they decrease? Did they find dead bees? What specifically is the evidence that they’re toxic to bees? Give me a legitimate source, a reputable scholarly journal, that says so.

    • What about the acaricides used by beekeepers? Think they have anything to do with it? Nope. Probably not. That’s why you have no place in a serious discussion on this topic. Go back to reading the Acres USA pseudoscience.

  11. I find it odd that you include the Oregon incident where thousands of bumblebees died as a result of exposure to the chemicals in question and make it sound like it was the experimenters who conducted a study, when in fact it was an incident for which the Oregon Department of Ag issued civil penalties. Using that kind of a shady approach to your subject makes me question the whole article.

    • I disagree, I think it was plainly worded with a link to a story about the incident from a local Portland paper. The article did reference the dosage used by the research team as being representative of this incident, but no mention was made that this research team was a part of that incident.

  12. Good read, I’m really fascinated watching this issue unfold. Where I live in the Pacific Northwest -CCD is a flashpoint among many enviromentally-minded groups. Listening to an episode of EconTalk (podcast) where Wally Thurman was interviewed (
    was what hooked me. filled in a lot more details, and has made my ears perk up as the science keeps coming in.
    Jon, the nit-picker in me twitched when I read one line in this article and I wondered if you could provide a source for this statement:

    Under the paragraph headed: “Real world impact of ban”

    “So the panic solution—an open-ended moratorium on the use of neonics—[[[has actually led to increased bee deaths]]].” -Is there a source I could look at for that, or attribute it to?


  13. what a hack job…. ask the bee suppliers how many packages of bees they are needing year after year… the numbers are staggering. Winnowing the genetic of bees through selective reproduction and exponential requeening is hurting the bee’s ability to fight maladies today and into the future. This article and the departments supposedly protecting us are strongly influenced by the monies unleashed by Citizens United. Its appalling that we play so carelessly with the balance of the planet as we know it. Articles like this only strengthen the disconnect tween truth and spin.

  14. Inconclusive, to me. Seems like the safest thing to do is find another, better pesticide that clearly, demonstratively does not harm the bees. We need ’em!

  15. In our area, activist hobbyist backyard beekeepers are the ones losing hives, and who are calling for a neonic ban. The professional beekeepers, who have an association, know that beekeeping is like keeping any other kind of livestock, and that skills, science, and best practices are needed to keep colonies going. The professionals do not call for the end of neonics as the activists do, and point out healthy hives very near farmer fields where neonic-treated seeds are used. They call for a much more reasoned and studied approach to beekeeping success, including workshops and training for beekeepers who do this for a living. This is an excellent article that points out the many fallacies and flaws of current misconceptions. Activist hobbyist beekeepers who don’t know what they are doing should not drive public policy based on their inability to successfully raise bees. In our area, pollinators of all types are on the rise, and neonic use has actually increased.

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