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 2 of 3
An immune-system disorder?
Meanwhile, beekeepers are seeing hives empty in a matter of weeks, sometimes days. The entire adult bee population vanishes, except for a few juveniles. This makes CCD difficult to study. "You have a crime scene, you know a crime happened here, but you don't really have evidence," says Medhat Nasr, provincial apiculturalist in Alberta, Canada. Eerily, the stored honey in the hive remains untouched. Raiding bees from nearby colonies never materialize, as is common.
Records of suddenly empty hives go back as far as the late 1800s, but never on this scale. Beekeepers dubbed it "autumn collapse," "spring dwindle," or "disappearing disease." But Dennis vanEngelsdorp, the acting Penn State apiarist, calls this manifestation the AIDS of bees. The remaining juvenile bees appear to be rife with disease. To him, "It's clear that there is an immune suppression," he says.
What might suppress a bee's immune system is anyone's guess. But many ascribe to a tipping-point theory: A variety of factors may have accumulated until a single straw finally broke the bee's back.
A review of honeybee history shows many suspects. The Varroa mite, native to Asia, came to North America in the late 1980s. Since then, yearly losses of between 15 and 20 percent have become the norm. "Before the mites, you could be a bee-have-er," says Mr. vanEngelsdorp. "Now you have to be a bee-keep-er."
Beekeepers are the first to acknowledge the stress of migratory pollination. Carted on flatbed trucks from wintering sites in the South, the bees crisscross the continent, first to California's almond groves, which rely entirely on honeybees for pollination, and then northward throughout the country, following the spring flowering season. Farmers have come to rely increasingly on honeybee services, says May Berenbaum, head of the department of entomology at the University of Illinois, Urbana-Champaign. "Given its economic importance, beekeeping really hasn't gotten the attention it deserves," she says.
Poor nutrition may be another factor, says Mr. Vaughan. To prepare them for winter, bees are fed high-fructose corn syrup and protein supplements. In the fields they've pollinated, meanwhile, more often than not they've gathered only one kind of pollen. Maybe, like other animals, they need a diverse diet, he says. "If you only ate McDonald's every day, you'd be just like that guy in 'Super Size Me,' " he says. "And he didn't feel that good."
Others, like Doan, suspect pesticides.
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