Finally, a link has been shown between pesticides and colony collapse disorder.

It’s been hypothesized that pesticides are the source of the global collapse of bee populations, but there had been no controlled experiments demonstrating correlation. A French government group performed just such an experiment and found that, indeed, colonies exposed to low levels of imidacloprid (a common, Bayer-developed insecticide) failed to thrive. They were 100–200% more likely to die while away from their nests, possibly because imidacloprid damages their ability to navigate back.