In the 1940s, there were around 5 million bee colonies in the United States. Today, there are only 2.5 million.
In recent years large-scale deaths of honeybees, colony-collapse disorder (CCD), have become more prevalent.
And though it's not entirely clear what is causing CCD, scientists have named a number of culprits, including fungi, viruses, Varroa mites, and neonicotinoid pesticides.
What does this all have to do with the U.S. economy? According to the USDA, bees add $15 billion of value to U.S. crops every year by pollinating them. And though honey bees are unlikely to disappear entirely, the cost of honey bee pollination services continues to rise, and those increased costs are being passed on to consumers through higher food prices.