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New research adds to evidence that pesticide is driving honeybee collapse

honeybee
REUTERS/Miguel Vidal
Scientists are scrambling to explain the mass disappearance of honeybees.

Two new studies about the impact of a controversial pesticide on bees came out late last week, in the prestigious journal Science, and stirred up a flurry of stories around the country.

This one, in the Strib, used the occasion for an update on the efforts of honey producers in Minnesota and elsewhere to seek an emergency ban on products from Bayer CropScience that they blame for massive and mysterious losses of honeybees.

It was a good piece, but narrow in the way that much of the coverage has been over the five or so years that “colony collapse disorder” or CCD has been in the headlines.

When it comes to environmental issues, Americans and therefore the American press like simplified and even romanticized narratives:

Man’s manipulation of the natural world, over here, wrecks the natural world over there — often by driving species to extinction. Big, modern businesses wipe out small, traditional businesses for the sake of profit. Environmental regulators abdicate responsibility by caving in to special interests, usually industrial but sometimes environmental.

Even the 2009 documentary “Vanishing of the Bees” — an excellent film, I want to emphasize — is too often inclined to stay within these familiar, empathetic themes.

Out of the ordinary

But if you watch it closely, you can also see the elements that lift this issue out of the ordinary, in ways that ultimately may help to save the bees and preserve the benefits they return not just to their keepers but to all of us.

Honeybees, you see, are not only victims of industrial agriculture. They are also one of its essential engines. And the modern beekeeper isn't a rustic, romantic honey producer — he's moving hives by the semi-trailer load over thousands of miles to pollinate some of the nation's most important crops.

In the U.S. alone, according to the Congressional Research Service,

bee pollination is involved in about one-third of the U.S. diet, and contributes to the production of a wide range of fruits, vegetables, tree nuts, forage crops, some field crops, and other specialty crops. The monetary value of honey bees as commercial pollinators in the United States is estimated at about $15 billion to $20 billion annually.

So when this fight heads to the courts, as seems inevitable, it may not be a David-and-Goliath affair with small business on one side, Bayer and corporate agriculture on the other. Quite likely it will be a contest between two wealthy agribusiness sectors, and therefore a fairer fight than many.

Nothing natural about these bees

There is nothing natural about a honeybee in America. The species is European, Apis mellifera, brought to this hemisphere and bred to industrial scale because “large, monoculture farms require intense pollination activity for short periods of the year, a role that other pollinators such as wild bees and bats cannot fill."

Those words are from Diana Cox-Foster and Dennis vanEngelsdorp, the researchers who in 2006 discovered a pattern of die-offs among honeybees that was strikingly different from past population declines. They gave it its name — colony collapse disorder.

For a fascinating account of their forensic investigation, and a clear explanation of the complicated findings it produced, I recommend their account published just three years ago in Scientific American (it's behind a pay wall but widely available online from libraries, too).

Honeybees, they point out, periodically experience large die-offs attributable to parasites, viruses and other agents. Varroa mites, for example, had wiped out nearly half of the world's managed bee colonies in the decade before CCD was identified.

If these pandemics can be likened to the Black Death or other plagues leaving the land covered in  corpses, the patterns of CCD are perhaps more akin to the emptying of Mayan cities in the Yucatan:  abrupt and virtually complete abandonment of complex communities by their members, who vanish without a trace and without an explanation.

During the winter of 2007, such collapses were reported by about 25 percent of American beekeepers; Cox-Foster and vanEngelsdorp calculated that 30 percent of all U.S. colonies had died.

More than a third affected

The next year was worse, with die-offs hitting more than one-third of American beekeepers. Large losses were also reported in Canada, Brazil, China, Australia and several European countries. (Some news reports suggest the die-offs have abated somewhat since then.)

CCD tends to leave behind small numbers of dead or weakened bees, and from autopsies on these the researchers

 ruled out many potential causes for CCD and found many possible contributing factors. But no single culprit has been identified. Bees suffering from CCD tend to be infested with multiple pathogens, including a newly discovered virus, but these infections seem secondary or opportunistic--much the way pneumonia kills a patient with AIDS. The picture now emerging is of a complex condition that can be triggered by different combinations of causes.

 Two causes, however, came in for special emphasis. One was simple malnutrition, a consequence of both urbanization and industrial-scale farming:

Honeybees and wild pollinators, too no longer have the same number or variety of flowers available to them because we humans have tried to "neaten" our environments. We have, for example, planted huge expanses of crops without weedy, flower-filled borders or fencerows. We maintain large green lawns free of any "weeds" such as clover or dandelions. Even our roadsides and parks reflect our desire to keep things neat and weed-free.

But to bees and other pollinators, green lawns look like deserts. The diets of honeybees that pollinate large acreages of one crop may lack important nutrients, compared with those of pollinators that feed from multiple sources, as would be typical of the natural environment. Beekeepers have attempted to manage these concerns by developing protein supplements to feed colonies--although the supplements have not on their own prevented CCD.

The other major culprit was neonicotinoids, a new type of insecticide introduced to the U.S. market by Bayer in the 1990s. The researchers found that these compounds were not only potentially toxic to honeybees, but also had been shown at lower doses to “decrease honeybees' ability to remember how to get back to their hive, a sign that they could be a contributor to CCD.”

The role of neonicotinoids

Unlike insecticides that are sprayed on growing crops, the “neonics” are applied to seed. As the plant grows, the substances are expressed in its tissues at levels that Bayer says are capable of protecting the crops and incapable of harming honeybees.

That position has been challenged vigorously over the years — a good summary, with attitude, appeared last week in Mother Jones — and it was challenged anew by research published Thursday in Science (where it remains behind the pay wall). Here how the AP summarized the studies, one from a French team working with honeybees and one from British researchers working with bumblebees:

 In the honeybee study, French scientists glued tiny radio transmitters to the bees managed for orchard pollination. The bees were tracked when they came and left the hive. Those that were dosed with neonicotinoids were two to three times more likely not to return. “Where’d they go? We have no clue about that actually,” said study author Mickael Henry, a bee ecologist for the French national agriculture institute. His study said the pesticide likely contributes to colony collapse.

 British researchers dosed bees with the pesticide and moved their hives out into the field. After six weeks, they found the pesticide-treated hives were 10 percent lighter than those that weren’t treated. And more important, the hives that had pesticides lost about 85 percent of their queens.  “Queen production is in some sense the be all and end all,” study author David Goulson of the University of Stirling in Scotland said.

Bayer replied that the honeybee study treated the insects with higher doses than they would acquire from crops, and that the bumblebees may be more sensitive to neonics than honeybees. Other entomologists said the studies were interesting but didn’t make a compelling case for the ban that beekeepers are seeking.

EPA officials said they are continuing to review research and will decide in 2018 whether to renew approval for neonics as seed treatments.

But I think it’s a good bet that this issue is headed for a courtroom long before then, and I think a Bayer victory is far from guaranteed. The evidence against its neonics appears to be growing and, with it, the case for protecting not just honeybees but major American agricultural sectors from harm.

CCD has no cure, and the immune system of bees is such that no vaccine is possible. Multiple causes may drive CCD but, realistically, insecticide exposure is the only one that can be readily removed; we’re simply not going to abandon industrial-scale monocultures of corn and soybeans.

Public opinion can play a role in these disputes as well. Perhaps Americans are beginning to realize, first, that more is at stake with CCD than a reliable supply of honey and, second, that this is a problem of some urgency.  As Cox-Foster and vanEngelsdorp observed,

Although CCD probably will not cause honeybees to go extinct, it could push many beekeepers out of business. If beekeepers' skills and know-how become a rarity as a result, then even if CCD is eventually overcome, nearly 100 of our crops could be left without pollinators — and large-scale production of certain crops could become impossible. We would still have corn, wheat, potatoes and rice. But many fruits and vegetables we consume routinely today such as apples, blueberries, broccoli and almonds — could become the food of kings.

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Comments (1)

Double edged sword

Bayer, like any big company with any relationship to crops, whether via seed production, seed treatment, plant improvement, or plant protection, has a stake in the health of crops, too. If a crop fails because their product caused it to, then not only will people voluntarily stop using it, but there will be no crop on which to apply the product. Bayer, and others, will likely need to consider their options very, very carefully. A company that sells seed treatment and has no seeds to treat is a failed company (in the case of Bayer, a failed division of a company, but still expensive). Thus, this will likely not be a David vs. Goliath, or even a Goliath vs. Goliath issue. It will be far more nuanced.

Right now, it's still at the hyped speculation stage. A good clue that we should probably consider the scientific question more carefully is when it pops into the main stream news as the answer to a big problem. Main stream news is infamous for pushing forward scientifically illiterate "news" directed as scientifically illiterate consumers. (Anyone willing to eat their printed words on vaccines and autism or the miracle of beta-carotene, yet?)