Wild bee decline threatens US crop production

The first national study to map U.S. wild bees suggests they’re disappearing in many of the country’s most important farmlands.

If losses of these crucial pollinators continue, farmers will face increasing costs – and the nation’s crop production may even destabilize, according to the Integrated Crop Pollination Project, a research effort funded by the USDA’s Specialty Crop Research Initiative. The findings were published on Dec. 21 in the Proceedings of the National Academy of Sciences.

The research team, led by Insu Koh at the University of Vermont and Rufus Isaacs at Michigan State University, estimates that wild bee abundance between 2008 and 2013 declined in 23 percent of the contiguous U.S. The study also shows that 39 percent of U.S. croplands that depend on pollinators – from apple orchards to pumpkin patches – face a threatening mismatch between rising demand for pollination and a falling supply of wild bees.

The new study 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 – such as almonds, blueberries and apples – that are highly dependent on pollinators. Or they are counties that grow less dependent crops – such as soybeans, canola and cotton – in large quantities.

The model’s confidence is greatest in agricultural areas with declining bees, matching both the consensus of experts’ opinions and available field data. However, the study also outlines several regions with greater uncertainty about bee populations. This knowledge can direct future research, especially in farming areas where need for pollination is high.

For more information visit the Integrated Crop Pollination Project’s website.