When CCD first hit, many people, from agronomists to the public, assumed that our slathering of chemicals on agricultural fields was to blame. Indeed, says Jeff Pettis of the USDA Bee Research Laboratory, "we do find more disease in bees that have been exposed to pesticides, even at low levels." But CCD likely involves multiple stressors. Poor nutrition and chemical exposure, for instance, might pummel a bee's immunities before a virus finishes the insect off.
It's hard to tease apart factors and outcomes, Pettis says. New studies reveal that fungicides—not previously thought toxic to bees—can interfere with microbes that break down pollen in the insects' guts, affecting nutrient absorption and thus long-term health and longevity. Some findings pointed to viral and fungal pathogens working together. "I only wish we had a single agent causing all the declines," Pettis says. "That would make our work much easier."
As managed bees take a hit, so too do wild pollinators, whose work pollinating U.S. crops is worth about three billion dollars annually. Some notable bumblebee species are rarely seen anymore, with others becoming increasingly scarce. But few of the scores of native pollinators, less visible and less valued than the big-money honeybees, have been monitored long term.
What to do? Give pollinators more of what they need and less of what they don't, and ease the burden on managed bees by letting native animals do their part, say scientists. Reduced reliance on chemicals in agriculture is part of the solution, says Buchmann, since all animals need their immune systems in top shape to combat pathogens in their environment.
Meanwhile, habitat loss and alteration, he says, are even more of a menace to pollinators than pathogens. Claire Kremen encourages farmers to cultivate the flora surrounding farmland to help solve habitat problems. "You can't move the farm," she says, "but you can diversify what grows in its vicinity: along roads, even in tractor yards." Planting hedgerows and patches of native flowers that bloom at different times and seeding fields with multiple plant species rather than monocrops "not only is better for native pollinators, but it's just better agriculture," she says.
Pesticide-free wildflower havens, adds Buchmann, would also bolster populations of useful insects such as blue orchard bees—an extremely effective pollinator of almonds in California. Native bumblebees in Wisconsin aren't as finicky about cold, wet weather as honeybees, so managing the landscape for their benefit would mean more buzz in the orchards in early spring.
Even in the busiest cities, pollinators can be coddled with a little creativity. Recent studies show that bees off the farm have a healthier and more varied diet than those making the commercial-crop rounds. Rooftop beehives in New York City help urban gardens and Central Park foliage flourish. And ecologists are now transforming part of what was once a 2,200-acre landfill on Staten Island into a flowering meadow to give native pollinators a sugar boost. It's a fairly simple calculation. If there's habitat, they will come.
Fortunately too, "there are far more generalist plants than specialist plants, so there's a lot of redundancy in pollination," Buchmann says. "Even if one pollinator winks out, there are often pretty good surrogates left to do the job." The key to keeping our gardens growing strong, he says, is letting that diversity thrive.
Take away that variety, and we'll lose more than honey. Many flowering plants would disappear, and with them apples, peaches, pears, and a host of other crops. Without pollinators there'd be no raspberries, blueberries, or even milk on your cereal (cows feed on bee-pollinated alfalfa and clover). No coffee or chocolate. No canola, a biofuel crop. No more summer watermelon or Halloween pumpkins. U.S. almond growers, who provide 80 percent of the world's crop, employ a third or more of the country's commercial beehives during the growing season—a bee extravaganza that's been called the largest pollination event on the planet. That too would fizzle.
"We wouldn't starve," says Kremen. But without the birds and the bees (and the bats and the butterflies), what we eat, and even what we wear—pollinators, after all, give us some of our cotton and flax—would be limited to crops whose pollen travels by other means. "In a sense," she says, "our lives would be dictated by the wind."