David Hackenberg, a commercial beekeeper in Lewisburg, Pennsylvania, sounded the alarm on 60 Minutes in 2007, explaining that he had lost a staggering two-thirds of his bees. Other beekeepers fared worse, losing up to 90 percent of their hives. Researchers termed the phenomenon “colony collapse disorder.” In affected apiaries, bees were inexplicably abandoning their colonies, often leaving behind food and young. The bees weren’t just lying there dead. They were gone. “It was like a ghost town,” Hackenberg told 60 Minutes.
The phenomenon became an epidemic, wrecking colonies of small independent beekeepers and large commercial operations alike. Beekeepers who responded to an annual US Department of Agriculture-funded survey reported losing, on average, more than a third of their hives every year from 2006 to 2013, though not all losses have been attributed to colony collapse. Beekeepers in the Northeast have been among those hardest hit.
As the toll mounted, beekeepers, scientists, federal regulators, the media, and environmentalists groped for answers, blaming, at various points, climate change, poor nutrition, fungus, cell-tower radiation, mites, viruses, and even a purported scheme hatched by Russian spooks. The latest consensus among regulators and some scientists is that a combination of factors, including parasites, pesticide use, and increasingly homogenized American agriculture, is what’s decimating the honeybee population. A US government report published in May concluded that “a complex set of stressors and pathogens is associated with CCD, and researchers are increasingly using multi-factorial approaches to studying causes of colony losses.”
The urgency of solving the puzzle is undeniable. Honeybees are critical to the food supply. About one-third of what we put in our mouths benefits directly or indirectly from honeybee pollination, according to the USDA. Without bees, harvests dwindle and food prices rise.
Every year, commercial beekeepers truck hundreds of thousands of hives from state to state to pollinate a multitude of crops, from tree nuts in California to cranberries in Massachusetts. Many make a good part of their living through pollination contracts with growers. In recent years, the US honeybee supply has diminished to the point where growers have had to import pollinators.
In his previous research, Alex Lu had focused on human exposure to pesticides, making his name with a study in the Seattle area, first published in 2005, showing that switching children to a largely organic diet could quickly and dramatically reduce the amounts of pesticide residues in their bodies. He knew no more about honeybees than the average consumer.
What he did know, however, was pesticides — their complexity, their ubiquity, and their potency. Seeing David Hackenberg’s story on 60 Minutes aroused his suspicions. Like Hackenberg himself, Lu had a hunch that pesticides, above all, were to blame for the vanishing bees. He wasn’t the first to see a connection, but he was determined to prove one.
THERE’S A CERTAIN GENIUS to pesticides known as systemics. Unlike traditional pest-killing chemicals, which are usually sprayed on crops, lawns, and trees, systemic pesticides render a plant toxic to bugs from the inside out. Seeds are treated with pesticide before they’re sowed (or sometimes the soil is pre-treated). When the plant grows, the poison essentially grows with it, spreading to all parts of the tissue and killing any snacking corn borers, rootworms, aphids, or stink bugs.
The big systemic pesticides these days are called neonicotinoids, which are derived from nicotine and target insects’ nervous systems. They have exploded in popularity over the past decade, thanks to a perception that they are both safer and more effective than the pesticides they replaced. The vast majority of corn planted in the United States today is pre-treated with neonicotinoids, the seeds colored like candy. So are other major crops such as soybeans and canola.
The wind, not bees, pollinates corn, but bees can collect corn pollen. And neonicotinoid-laced pollen blows onto nearby flowers and crops, exposing honeybees to the poison. Neonicotinoids are also used on plants that bees do pollinate, including cucumbers and watermelons. Unlike older pesticides, neonicotinoids can linger in the soil for months or even years.
The more Lu learned about colony collapse, the more convinced he became that the epidemic’s timing was no coincidence, coming as neonicotinoid use surged in American agriculture. With a $25,000 grant from Harvard, he began designing an experiment to test his hypothesis, aiming to replicate the honeybee disappearances that beekeepers were experiencing. It was clear neonicotinoids were acutely toxic to bees, just as they were to crop-eating insects, but what about at lower levels, over a prolonged period of time?Continued...