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What's happening to the bees?
Suddenly, the bees farmers and growers rely on are vanishing. Researchers are scrambling to find out why.
from the April 4, 2007 edition
Page 3 of 3
Similar problem in 1990s France
In the 1990s, France experienced a precipitous honeybee decline from "mad bee disease." Honey production dropped by nearly one-third, to 25,000 tons. French beekeepers blamed a newly introduced pesticide marketed under the name Gaucho. From the same family as nicotine, the chemical targeted aphids' navigational systems. And when the honeybees weren't finding their way home, either, French beekeepers protested. The French government banned the product in 1999. Though subsequent studies haven't found a strong link, bee populations still haven't rebounded to previous levels.
Others point to genetically modified crops – specifically, those with a gene for a bacterial toxin called Bt. Initial studies indicated that it didn't affect bees. But some beekeepers argue the trials didn't last long enough to determine the long-term effects. (Doan says the same about the nicotinelike pesticides.) A German study supports this. Scientists at the University of Jena found that while Bt food had no direct effect on bees, when fed to bee populations infected with parasites, they quickly became diseased. Alone, Bt may do nothing. But in the presence of a parasite, it may facilitate infection.
"Maybe these toxins weaken the immune system," says John McDonald, a retired biologist and hobby apiculturalist in Spring Mills, Pa., who wrote an editorial on the topic for the San Francisco Chronicle
But the shrinking of our so-called "pollination portfolio" is of more concern to many entomologists than a die-off in commercial beehives. A 2006 National Academy of Sciences report declared that there was "direct evidence for decline of some pollinator species in North America" – species responsible for pollinating three-quarters of flowering plants. Europeans have documented a parallel decline in their natural pollinators for years.
On the US East Coast, where a more ecologically diverse farming landscape enhances species diversity, studies have shown that wild pollinators were doing about 90 percent of the pollinating anyway, says Neal Williams, an assistant professor of biology at Bryn Mawr College in Pennsylvania. "It seems a little bit silly from a whole-country perspective, even from a farmer perspective, that we would place so much emphasis on one species. We don't do that with any other part of the economy," he says.
Meanwhile, a Canadian study suggests that if canola farmers leave 30 percent of their land fallow, they will increase their yields. Wild land provides habitat for native pollinators, improving pollination and increasing the number of seeds. "If we cultivate all the land, we lose ecosystem services like pollination," says Lora Morandin, lead author on the study. "Healthy, sustainable agricultural systems need to include natural land."
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