Wild bees are disappearing in the country’s key farmlands from California to the Midwest to the Mississippi Valley, say researchers at the University of Vermont in the first study to map U.S. wild bee populations. The study found a 23-percent decline in wild bees in the contiguous U.S. between 2008 and 2013.
“The map identifies 139 counties (39 percent of croplands that depend on pollination) in key agricultural regions of California, the Pacific Northwest, the upper Midwest and Great Plains, west Texas, and Mississippi River valley, which appear to have most worrisome mismatch between falling wild bee supply and rising crop pollination demand,” say the researchers.
Even though two-thirds of the world’s crops depend on pollination, it may be that the development of farms is the greatest threat to wild bees. In addition to pesticides, climate change and pathogens, the bees face tremendous habitat destruction.
“In 11 key states where the map shows bees in decline, the amount of land tilled to grow corn spiked by 200 percent in five years — replacing grasslands and pastures that once supported bee populations,” says the study’s authors, who are hopeful that their findings will help conservationists focus their efforts on the most critical habitat areas.