Wild Bee Decline May be Putting Pressure on Farms: What is Killing These Pollinators?

There's a lot of talk about bees, but this time it's serious. Wild bees are disappearing in many of the U.S.'s most important farmlands, including California's Central Valley, the Midwest's corn belt, and the Mississippi River valley. Now, researchers are trying to find out why.

The research team estimates that wild bee abundance between 2008 and 2013 declined in 23 percent of the contiguous U.S. Scientists also found that 39 percent of U.S. croplands that depend on pollinators, such as apple orchards and pumpkin patches, face a threatening mismatch between the rising demand for pollination and falling supply of wild bees.

Of particular concern, the researchers found that the crops that are the most dependent on pollinators have the strongest pollination mismatch. In the future, these crops are likely to run into pollination problems.

But what's causing this decline? The scientists found it may partly be the conversion of bee habitat into cropland. In eleven key states where the new study showed bees in decline, the amount of land tilled to grow corn spiked by 200 percent in just five years. This replaced grasslands and pastures with croplands.

"Until this study, we didn't have a national mapped picture about the status of wild bees and their impacts on pollination," said Insu Koh, one of the researchers, in a news release. "Now we have a map of the hotspots. It's the first spatial portrait of pollinator status and impacts in the U.S."

The researchers hope that this new tool could be used to protect wild bees and pinpoint habitat restoration efforts. As it is, it seems as if bee populations are in serious trouble.

"We can now predict which areas are suffering the biggest declines of wild bee abundance, and identify those areas, with low bee supply and high bee demand, that are the top priority for conservation," said Koh.

The findings are published in the journal Proceedings of the National Academy of Sciences.

Related Stories

For 8,500 Years, Humans Have Relied on Bees, Their Honey and Their Wax

Honeybees Naturally Vaccinate Their Babies with Their Blood

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).