A decline in bee numbers across America is threatening the nation’s crop production, recent research suggests. The first national study to map U.S. wild bees shows that numbers declined in 23 per cent of the contiguous U.S. between 2008 and 2013.
If losses of these crucial pollinators continue, farmers will face increasing costs, it warns — and that may destabilise the nation’s crop production.
The study, which is the first of its kind in America, shows that 39 per cent of U.S. croplands that depend on pollinators — from apple orchards to pumpkin patches — face a falling supply of wild bees.
It identifies 139 counties in key agricultural regions of California, the Pacific Northwest, the upper Midwest and Great Plains, west Texas, and the southern Mississippi River valley that have the most worrisome mismatch between falling wild bee supply and rising crop pollination demand.
These counties tend to be places that grow specialty crops — like almonds, blueberries and apples.
“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, a researcher at the University of Vermont, which led the study, in a statement – even though each year more than USD 3 billion of the U.S. agricultural economy depends on native pollinators like wild bees.
Thanks to the assessment, the researchers have a tool that they hope will help protect wild bees and pinpoint habitat restoration efforts.
Pesticides, climate change, and diseases threaten wild bees — but the new study also shows that their decline may be caused by the conversion of bee habitat into cropland.
In June 2014, the White House issued a presidential memorandum warning that “over the past few decades, there has been a significant loss of pollinators, including honey bees, native bees, birds, bats, and butterflies.”
The memo noted the multi-billion dollar contribution of pollinators to the U.S. economy — and called for a national assessment of wild pollinators and their habitats.
Photo credit: Ken Slade/ CC BY-NC 2.0