What’s been killing all the honeybees? It took an unusual partnership between the Army and entomologists to find out. In the last four years, between 20 and 40 percent of honeybee colonies have collapsed, baffling scientists who couldn’t find a culprit. This unlikely team has found two. A fungus and a virus worked together to decimate the bees, reports Maryland military scientists working with Montana bee experts. The scientists are unsure how the germs kill the bees, but have several clues. Both the virus and the fungus work in the bee’s digestive tract, meaning the collapses have something to do with nutrition. And both like cool, damp environments. Both the Army scientists and the entomologists say they would have never figured out the honeybee killer on their own, crediting their success to luck, open communication, and sharing techniques, like in performing bee autopsies.