Field biologists have a strange affinity for spending countless hours in the hot sun scrutinizing tiny things. You might see a bee buzzing on a flower and think, “Oh, a bee.” A biologist, though, will want to know: Is it a nonnative, domesticated honeybee? Or is it one of 4,000 bee species native to the U.S.—maybe an ultragreen sweat bee, a metallic-sheened creature that drinks human perspiration? Or perhaps a cuckoo bee, such as Bombus suckleyi, a type of bumblebee that sports yellow hair on its fourth abdominal segment, as opposed to the rare B. occidentalis, which has black or white hair in the same spot?
You also can probably name many reasons not to sit in a field counting grains of pollen, an activity that conservation biologist Claire Kremen thinks is a perfectly reasonable way to spend an afternoon. But then, you probably will not be the one to revamp the nation's food supply and rescue our agricultural system from looming collapse. Kremen, however, just might.
A decade ago, after years of work in Madagascar, she turned her attention to a problem brewing closer to home. Colony collapse disorder (CCD) had not yet been diagnosed or named, but already American beekeepers were reporting record deaths within their honeybee hives. A third of the U.S. food supply depends primarily on the honeybee for pollination—apples, almonds, peaches, lettuces, squashes, melons, berries and broccoli, to name a few crops. Kremen, now at the University of California, Berkeley, began to wonder about other kinds of bees. Could wild native bee species ease our dependence on honeybees by lessening their workload?
With Neal Williams, at the time a graduate student in her then Princeton University laboratory, and Robbin Thorp, a renowned bee taxonomist, Kremen studied watermelon pollination in California's Central Valley. Kremen and her team monitored how frequently each of 39 different bee species visited a flower and how much pollen each bee deposited. Based on previous studies, they knew that it takes around 1,000 grains of pollen to build a single juicy watermelon. Growers on organic farms surrounded by wild plants, it turned out, did not even bother hiring hives. The native bees did all the work, saving the farmers money year after year. In contrast, on conventional monoculture farms with large swaths of a single crop the wild bees barely made a dent. Without honeybees, those farmers would be looking for new jobs.
The resulting paper, published in 2002 in the Proceedings of the National Academy of Sciences USA, concluded that by restoring native bee habitat in their fields, farmers could “hedge their bets in the event of honey bee scarcity through partial replacement of honey bee by native bee services.” In the decade since, other researchers have cited the paper—now seen as prescient—614 times. During that period, CCD has joined the already long list of maladies afflicting honeybee hives, and the economic fortunes of beekeepers have grown increasingly perilous. “Bees,” says Kremen, who won a “genius” grant from the MacArthur Foundation in 2007, “are telling us something very fundamental about our agricultural system and how off-balance it is.”
Kremen's work is now funded in part by the U.S. Army, which wants to safeguard the nation's food security. “It's a component of creating a resilient system,” she says. Plants that require animal pollination contribute 98 percent of the total vitamin C supplied by major global crops, 70 percent of vitamin A, 55 percent of folic acid and 74 percent of lipids. “If all the pollinators went extinct, we probably wouldn't starve,” Kremen says. “But we'd all have scurvy or some other vitamin-deficiency disorder.”
The honeybee crisis underscores the tremendous risk we have unwittingly built into our farm system by relying on a single insect to pollinate so much of our food supply. As author Hannah Nordhaus put it in her book The Beekeeper's Lament, “Farmers expect bees to function like yet another farm machine—like shakers, sweepers, tillers and combines.” But honeybees are living creatures, subject to the realities of biology. And despite 400 years of domestication, there are still many things about honeybee biology we cannot control—for instance, the insects' susceptibility to parasites, viruses and climatic conditions. They may be domesticated, but they do not exactly stay in a pen as cattle do.