Yellow, Black, and Blues

What We Know / by Joe Kloc /

A look at our agricultural past may explain why honey bees around the world began disappearing three years ago.

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The unknown culprit was originally dubbed “Fall-Dwindle Disease.” Soon after, however, it was renamed “Colony Collapse Disorder.” This revision itself suggests the peculiarities that began to plague investigations of the phenomenon. First, the die off did not end in the fall. It kept going through the warmer months, year-after-year, up to today. And the bees did not “dwindle,” as might be expected from a usual sickness. When Hackenberg examined his hives, only the brood—the developing eggs, larvae, and pupae—along with the queen and a handful of nursing bees had survived. A few of the dead workers were found in or around the hive, but the majority seemed simply to have disappeared. Whatever was happening, “disorder” was increasingly the word to describe it.

“Back in 2006 and 2007, we had three major hypotheses,” says Diana Cox-Foster, an entomologist at Pennsylvania State University. “The first was that new or emerging pathogens were underlying the loss of colonies, the second was that environmental toxins could be involved, and the third was that a combination of stressors—like the lack of proper nutrition—was to blame.”

Thus far, scientists have identified 18 different viruses troubling the honey bees, many of them lethal. But the problem is that if you pick any one of these viruses, eventually you can find a case of Colony Collapse Disorder where that particular pathogen wasn’t involved. And controlled tests looking at how viruses affect colonies in greenhouses have revealed that even the most likely candidates simply don’t kill bees in the same way CCD does. Similarly, investigations into pesticides as a culprit found that chemicals toxic to bees were indeed present in pollen samples—only, they were usually in non-lethal doses. And in Europe, where many of these chemicals were no longer in use, cases of CCD were also being widely reported. These toxins were certainly capable of affecting the bee’s behavior, but a pesticide, it seemed, did not a killer make. As for stressors, it has been no secret that our current practice of migratory beekeeping taxes the bee’s health. But the danger of shipping them across the country and feeding them from vats of fructose syrup—a monosaccharide bees never evolved to consume as a liquid—had existed long before the onset of CCD in 2006.

By June 2009 a report issued by the USDA had accepted—not without a hint of resignation—that “it now seems clear that no single factor alone is responsible for the malady.” Stopping honey bee colonies from collapsing wouldn’t be as easy as banning a pesticide or killing a new pathogen. Instead it appeared an interaction of different factors must underpin CCD—for instance, a pesticide might have weakened the bees’ immune systems enough so that a new virus proved lethal. And indeed, in 2009, a study at the French National Institute for Agricultural Research for the first time confirmed that pathogens and pesticides in combination could have synergistic negative effects on bees. “Scientists were suspicious that the parasite Nosema was playing a role in CCD but what that role was remained unclear,” says Cédric Alaux who worked on the study. Nosema had been found in a lot of bee colonies suffering from CCD, but when tested in controlled experiments the parasite didn’t seem particularly lethal. It was when Alaux’s group exposed honey bees to non-lethal doses of a pesticide in addition to Nosema, that the combination proved deadly. “There was a kind of synergy between the pathogen and the pesticides,” says Alaux.

With that, it became all but certain that getting to the root cause of CCD would be exceedingly more complicated than had originally been thought. All of this, of course, is before considering the toll that centuries of agricultural modernization had taken on the fragile—but indispensable—honey bee.

When the honey bee first came to the New World in 1622 it was known by the Native Americans as the “white man’s fly.” Thomas Jefferson made note of this in 1781, writing that, “the bees have generally extended themselves into the country, a little in advance of the white settlers.” Indigenous people saw the bees as a harbinger of what we might now call modernization. And in many ways the bees were modern. After centuries of being bred in Europe, they had very much become a product of their human caretakers. Back then it was common practice that when it came time to collect honey, beekeepers would walk around their apiaries, lifting each hive off the ground, checking its weight. Bees in the heaviest hives were killed so that their honey could be harvested. The lightest—poorest producing—hives were merged in the hopes that together they could make more honey. According to Gene Kritsky, a College of Mount St. Joseph Entomologist and Editor-in-chief of American Entomologist, an unforeseen consequence of this was that “going back centuries we had basically been selecting for a poorer bee.”

But the bee thrived in the New World as beekeeping spread throughout the colonies. The honey bees allowed colonists to plant crops like apples, a non-indigenous fruit largely helpless in North America without the non-indigenous honey bee to pollinate it. Colonists didn’t immediately recognize the importance of the honey bee as a pollinator for apple trees, but they had brought with them everything they needed to grow large patches of a single crop. It was, to say the least, an impressive accident.

The practice of sowing large tracts of land with only one crop variety, known as monoculture, increased steadily through the Industrial Revolution. When the 20th century rolled around, nitrogen fertilizers, mechanized farming equipment, railways, roads, and other innovations were enabling the cultivation of larger and larger monoculture crops. One natural limit to monoculture was imposed by the fact that at some point, if your crop was too large, you would be unable to find enough bees to pollinate it. But in 1908 a Utah beekeeper realized he could double his profits by shipping his hives by train to California during the winter months. With that, the migratory beekeeping industry was born. Farmers began paying beekeepers to haul their bees across the country every season, allowing them to plant as much as they liked, provided they could afford the added cost of hiring extra pollinators. California’s almond growers, for example, each spring enlist the services of half of all honey bee hives in the US. “They contract beekeepers to load up flatbed trucks with hundreds of beehives and place them on pallets in the middle of almond groves,” says Kritsky. “Then the bees might go to apples in Washington. And then maybe to Texas for cotton. Then it starts all over again.” The bees, quite simply, get strung out—a problem only exacerbated since the 1940s, when pesticides came into widespread use and spurred a further increase of monoculture farming. “We are forcing the bees to do things that they never evolved to do,” says Kritsky.

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