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Are pesticides to blame for the massive bee die-off?

Commercial beekeepers across America have been struggling with great numbers of bee deaths over the past few years. What’s behind their failing health? Some research points to a class of pesticide that’s coated onto a large proportion of corn and soybeans grown in the U.S. Allison Aubrey of NPR reports.

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  • Judy Woodruff:

    In this week when we think about food, we take a look now at the vital role bees play in getting some of your favorite dishes to the table, and the way commercial beekeepers in the U.S. are struggling to keep their bees healthy.

    Allison Aubrey of National Public Radio has our report.

    The story is part of the NewsHour’s ongoing collaboration with NPR.

  • Allison Aubrey:

    It’s harvest time at Adee Honey Farms in Bruce, South Dakota. Bret Adee’s the third generation to manage the 80,000 hives the Adees have scattered across five Midwestern states. He says beekeeping these days is much harder than it’s ever been.

  • Bret Adee, Adee Honey Farms:

    In 2010, our bees were just destroyed in a couple of weeks. Most of our bees died.

  • Allison Aubrey:

    Bret says things really haven’t improved much.

  • Bret Adee:

    I would to see about twice to three times as many bees in most of the hives right now. It will be a real challenge to keep them alive through the winter.

  • Allison Aubrey:

    The Adees are not alone. According to a preliminary survey from the U.S. Department of Agriculture, commercial beekeepers lost 42 percent of their colonies last year. Bees are a critical part of agriculture.

    Adee trucks his bees out to pollinate California’s almond groves every year. And it’s not just almonds. Bees pollinate everything from apples to cherries and squash. To figure out what’s plaguing the bees, the Obama administration assembled a task force last year. Scientists at the EPA, USDA and researchers across the country who have been studying the problem are finding there are multiple issues.

    Bees have fewer wildflowers to forage on due to a loss of habitat. There’s viruses that pests pass on to the bees. Climate change is thought to play a role too. Another issue is pesticides. Some studies suggest that a class of pesticides known as neonicotinoid, or neonics for short, are harming the bees.

    These pesticides are coated onto the seed of about 80 percent of the corn that’s grown in the United States and about half the soybeans too. To get a sense of that scale, imagine a cornfield like this taking up the entire state of California. That’s how much of this pre-treated seed is being planted.

  • Christian Krupke, Purdue University:

    This is what corn seeds look like after they have been treated.

  • Allison Aubrey:

    The pesticide is put onto the corn before it’s ever planted?

  • Christian Krupke:

    That’s right.

  • Allison Aubrey:

    Christian Krupke is an entomologist at Purdue University who studies bees. His research shows that neonicotinoids can harm bees.

    What is a neonicotinoid?

  • Christian Krupke:

    A neonicotinoid is — as the name would suggest, it’s based on nicotine. They’re less toxic to mammals, which is a big feature in their wide adoption. But they are more toxic to honey bees and to other insects.

  • Allison Aubrey:

    Neonics are a relatively new class of pesticide. They have been around since the early 1990s. They are easier for farmers to use than the traditional method of spraying crops. And according to researchers at Penn State University, their use has increased more than 11-fold since 2003. Companies that sell them are making billions of dollars.

  • Christian Krupke:

    Virtually all of these large acre plants are being treated. So, the level of use is way out of step with the level of the threat. In most fields, and where we have worked, we just haven’t been able to find levels of pests that would justify the level of use.

  • Allison Aubrey:

    Krupke published a study that linked bee deaths with the pesticide-laden dust that flies up during the planting of the pre-treated corn seeds.

  • Christian Krupke:

    We collected some of those bees and analyzed them and found neonicotinoids on them and in them, so there is an intersection between planting these crops and killing foraging honey bees.

  • Allison Aubrey:

    Bayer CropScience is one of the leading manufacturers of neonicotinoids. Bayer’s chief scientist, David Fischer, acknowledges Krupke’s findings, but he says Bayer has a seed lubricant that reduces the dust. He says that, outside these acute exposures, neonicotinoids are not harmful to bees.

  • David Fischer, Bayer Cropscience:

    We have done those studies. And those studies basically show, if you spray the product, it’s not safe for the bees. If you apply the product to the soil or as a seed treatment, the level of residues that gets up into the plant is in a safe range.

  • Allison Aubrey:

    Christian Krupke is not convinced.

  • Christian Krupke:

    We find these pesticides in the water. Bees drink water. Plants use water. We find that wildflowers that grow near these areas also have some of these pesticides in them. You add that up over the course of a season, and, yes, we do find concerning levels.

  • Allison Aubrey:

    Krupke says those levels do not kill the bees, but may leave them more vulnerable.

    Bayer’s chief scientist says the major threat to bees is a mite that punctures the honey bees body and feeds on its blood. It’s known as the Varroa mite. And a recent report issued by President Obama’s task force also points to the mite as one issue.

  • David Fischer:

    Eighty percent of the problem is Varroa mites and the viruses and the diseases those viruses cause.

  • Allison Aubrey:

    But some beekeepers suspect the increased use of the newer pesticides is making their bees more vulnerable to the mite.

  • Bret Adee:

    For 15 years, we managed that Varroa mite and kept our losses under 5 to 8 percent. Now we’re losing 50 percent of the bees every year.

  • Allison Aubrey:

    Pesticide manufacturers, including Bayer and Syngenta have launched campaigns of their own to boost bee health. Both companies are planting millions of flowers in the U.S. to increase bee forage.

    And in 2014, Bayer CropScience opened this $2 million bee care center in North Carolina, where they conduct workshops and tours. Environmentalists say these initiatives are a diversion from the real problem, the pesticides these companies manufacture, something Fischer rejects.

  • David Fischer:

    Bayer has actually been in the business of providing products to beekeepers for more than 20 years. It’s not something that we just started doing.

  • Allison Aubrey:

    Beekeepers in Europe came out in force a few years ago in support of the European Union’s partial ban on the use of some of these neonics.

    And here in the U.S., the Environmental Protection Agency says it will speed up a safety review and likely not allow any new uses of the pesticide. Environmental groups are locked in several court battles challenging the EPA over the registration of these pesticides.

    Manufacturers maintain that neonics are vital for increasing crop production and safer than spraying.

  • David Fischer:

    They’re extremely valuable. They increase crop yields often by 20 percent vs. the other competitors. So, they contribute billions of dollars to the ag economy in the United States.

  • Christian Krupke:

    That would be true if these products, these neonicotinoids, were indispensable to these crops, to agriculture, but they’re not.

    Some of our own work in corn and the work of others in the United States has shown that it’s very difficult to consistently show a yield benefit.

  • Allison Aubrey:

    Lucas Criswell farms close to 2,000 acres of corn, soybeans, wheat and rye in Pennsylvania’s Susquehanna Valley. He has stopped using treated seed because he found it wasn’t only killing the bad pests, but the pests he needed to ward off the slugs that were eating his soybean crops.

  • Lucas Criswell, Farmer:

    The soil in our fields are a huge ecology of different critters and insects. And they’re all there. We need good and bad. It takes a balance of them all, and that’s what we have seen.

  • Allison Aubrey:

    Criswell now keeps pests at bay in his fields by planting crops that encourage beneficial insects. The treated seeds cost more, so this method ends up being cheaper for him.

    Is it too soon enough to say whether you’re getting the same yields?

  • Lucas Criswell:

    Is there corn growing on that hill? It grew.

  • Allison Aubrey:

    It looks like a lot of corn.

    Earlier this year, President Obama’s task force called for a reevaluation of the pesticides. And, consistent with the president’s requirements, the EPA has expedited its review.

    I’m Allison Aubrey of NPR News for the PBS NewsHour in Bruce, South Dakota.

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