A bee visits a sunflower. Photo by TexasEagle / CC BY-NC 2.0
Turns out wilder is better, at least when it comes to pollinating fruity crops. Research published in Science last week suggests that domesticated honeybees—harvested by beekeepers and then employed to pollinate vast expanses of cropland around the world—are actually less efficient than wild pollinators are. The authors suggest farmers revert to an agricultural system that favors wild pollinators, instead of toying with monoculture and vast genetically modified crops the way we have to produce the food we eat.
By surveying 41 crop systems encompassed by 600 fields in 19 countries, an international team of scientists gleaned information about the kinds of pollinators and the crop yields at each site. They found that while wild pollinators—bumblebees and carpenter bees, for instance—brought widespread improvement in fruit yields, visiting domesticated honeybees encouraged fruiting in only 14% of the crops surveyed. National Public Radio (NPR) says the researchers showed that “even when beekeepers installed plenty of hives in a field, yields usually got a boost when wild, native insects, such as bumblebees or carpenter bees, also showed up.”
“The surprising message in all of this is that honeybees cannot carry the load,” Marla Spivak, a professor of entomology at the University of Minnesota, said to NPR. “Honeybees need help from their cousins and relatives, the other wild bees.” It appears that wilder creatures have a better knack for knowing what flowers want.
It’s welcome news, as farmers are becoming increasingly wearied by plights that kill off their commercial honeybees. Colony Collapse Disorder has been wiping out populations since 2006, and its cause is still unknown. Add to that a host of other threats (some of which are actually suspected causes of colony collapse too): mites, pesticides, stress, and viruses are also being blamed for the demise of the honeybee.
But wilder bee strains don’t have an easy ride either, and this is where the complexity sets in. Wild pollinators, this recent study says, might be best at pollinating, but in order to survive they need a landscape that is more varied than the monoculture carpet we have today. NPR draws attention to another recent study that shows how bee species have been slashed by 50 percent over the last 120 years.
According to the Los Angeles Times:
Scientists have long warned that plowing landscapes into vast, single-crop fields and orchards eliminates the range of soil, wildflowers and other vegetation that is crucial to support multiple species of wild pollinators, including bees, flies, beetles and butterflies.
The Times goes on to report that as these populations of valuable pollinating insects have been driven down by a changing landscape, farmers have turned more and more to “rented” replacements, like the Apis mellifera—the honeybee.
“Honeybees cannot replace the service wild bees provide,” Lucas Garibaldi, one of the most recent paper’s authors told the Los Angeles Times. “Biodiversity in agricultural landscapes matters and can help increase production.”
The take-home message is that farmers can’t do without wild buzzers, but they also need to actively save them by changing the way that they farm—and by encouraging interaction between commercial and wild pollinators. Audubon’s Ted O’Callahan wrote about ventures like this that already exist, as he explored the growing tendency towards supporting native bee species. The new research also suggested that wild bees, when intermingling with domesticated ones, actually guide the honeybees, encouraging them to fly in amongst more trees. “So let’s do something to promote it, so that we can keep honeybees healthy and our wild bee populations healthy,” Marla Spivak said to NPR.
Researchers suggest interspersing crops with other plants that flower throughout the year, and reducing the size of farms. From above, wild bees might spot the colorful, diverse patchwork below and zip down to do their thing—and help us out in the process.