Where the Wild Bees Are

November 13, 2009

By Jessica Goldman

beesJust as we grow accustomed to the concept of buying local food, it’s time to explore a new movement in agricultural sustainability — local bees.

Although Colony Collapse Disorder (CCD) no longer makes the kind of headlines it did in 2007, the plight of the honeybee continues. In the initial year CCD was observed, American beekeepers lost an average of 30% of their hives, and they’ve reported rates of 29% – 35% die-off each year since. While no one can confirm an exact reason for the disappearances, its clear that honeybees may not be a reliable agricultural resource on thier own for much longer.

As Claire Kremen sees it, however, the collapse of the honeybee population may be less of a clear cut “crisis” than it appears. At a recent lecture, the UC Berkeley professor and 2008 MacArthur Foundation fellow outlined the problem, and potential solution, in its much wider context.   

“Will we ever lose all of our pollinators?” Kremen asked her audience. “No.  But scarcity is possible.” Especially if we continue to count solely on honeybees to do the job.     

Over 30% of the United States food production depends on managed colonies of European honeybees, but professor Kremen has her eye on a different set of pollinators. Since 1998, she has studied the habits of wild bees and she believes they can meet our agricultural needs — if we learn to accommodate theirs.

How the honeybee became queen
There are over 20,000 known species of bees in the world, 4,000 of which are native to the United States and 1,500 of which exist in California alone.  So how did we become so reliant on a single species of bee?

The industrialization of agriculture caused a shift from multi-crop farming to a monoculture system — growing a single crop species over many acres.  As a result, harvesting schedules condensed and pollinator demands increased. (California almond farming, for example, now requires the pollination of over 600,000 acres of almond groves over 22 days).  Farmers needed easily controlled pollinators and honeybees were the ideal candidates because, unlike most wild bees which nest underground or in logs, they’re social and willing to nest in transportable hives. Today, a million honeybee hives are shipped annually to California almond farms, 50,000 to Maine blueberry farms, and 30,000 to New York apple farms.

In many ways, use of managed honeybee populations has proven efficient for farmers, but this system has also had negative impacts on farm ecosystems. As farmland has lost its diversity it has become less hospitable to wild bees, and crops and pollinators have become more vulnerable to conditional fluctuations (such as CCD). Without other species to pick up the slack, some agriculture could face a pollination gap.

Beyond the Honeybee
fieldKremen believes that a restoration of diversity will curb the consequences of CCD.

“We will still need honeybees and there’s nothing wrong with that,” Kremen says. But, she adds, a pollination system which also draws on wild bee populations will alleviate our dependence on the honeybee and produce an “agricultural insurance policy” for farmers.

In a 2006 study, Kremen, along with a team of UC Berkeley and UC Davis researchers, discovered that managed honeybee populations were five times more effective in pollinating sunflowers when wild bees were present. Wild bees made the honeybees nervous and triggered them to change their flight pattern and cover more ground.  The addition of wild bees increased productivity of the honeybees and in turn reduced the number of hives needed.
As a next step, Kremen aims to prove wild bees capable of pollinating crops without the assistance of honeybees.  She calls this the “Field of Dreams Project,” testing the theory that if we build the right environment, wild bees will come and will successfully pollinate.  In regions of California and New Jersey, Kremen found that farms in proximity to natural habitats with adequate nesting sites and food sources attracted enough native bees to pollinate an entire crop on their own.

But for this to work, farmers would need to restore 20% to 30% of California farmland to natural landscapes. While a change of this scale may not be realistic at this point, Kremen still champions the importance of small steps. By simply planting hedgerows and maintaining plots of undisturbed soil for nesting sites, Kremen says farmers can help reverse the effects of CCD, decrease our dependence on the honeybee, and finally welcome our wild bees back home.

Want to attract wild bees to your garden?
Read about what to plant >

Watch a trailer for a new bee documentary
Nicotine Bees >

Jessica Goldman blogs at sodiumgirl.blogspot.com

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