Bee colonies have been dying at alarming rates over the last few years. Things are so bad that South Dakota's 93 commercial beekeepers (and everyone else who likes to eat and thus needs bees to pollinate crops along with making honey) have to consider it "hopeful" news that only 23% of bee colonies collapsed last year, compared to 30% the year before. 18.9% die-off is considered the threshold for profitability. Ugh.

So what is decimating the bee colonies? This industry newsletter lists the following possibilities:

Bee health is impacted by a variety of stresses, such as viruses and other pathogens, parasites like varroa mites, problems of nutrition from lack of diversity in pollen sources, and even pesticides combining to weaken and kill bee colonies, said Jeff Pettis, research leader of the Agricultural Research Service (ARS) Bee Research Laboratory in Beltsville, Md [Allison Floyd, "More Bee Colonies Survived This Winter, Survey Shows," Growing South Dakota, 2014.05.16].

Did you notice that we mention that one human cause, pesticides, last in the list? New research from Harvard suggests we should move widely used neonicotinoid pesticides to the front of the line:

...a new Harvard study fingers neonics as the key driver of colony collapse disorder. The experiment couldn't have been simpler. Working with nearby beekeepers, Harvard researcher Chensheng Lu and his team treated 12 colonies with tiny levels of neonics and kept six control hives free of the popular chemicals. All 18 hives made it through summer without any apparent trouble. Come winter, though, the bees in six of the treated hives vanished, leaving behind empty colonies—the classic behavior of colony collapse disorder. None of the six control hives experienced a CCD-style disappearing act, although one did succumb to a common-to-bees gut pathogen called nosema [Tom Philpott, "Did Scientists Just Solve the Bee Collapse Mystery?" Mother Jones, 2014.05.20].

Neonicotinoid producer Bayer disputes the findings, of course... because they have a product to sell and shareholders to keep rich.