A fungus tag-teaming with a virus have apparently interacted to cause the problem, according to a paper by Army scientists in Maryland and bee experts in Montana in the online science journal PLoS One.
It's intriguing to read about some of the reasons that this disease, or syndrome, or whatever you call it, has been so hard to diagnose:
One perverse twist of colony collapse that has compounded the difficulty of solving it is that the bees do not just die — they fly off in every direction from the hive, then die alone and dispersed. That makes large numbers of bee autopsies — and yes, entomologists actually do those — problematic.
One of the techniques used in the investigation involved the deployment of a new software tool:
The Army software system — an advance itself in the growing field of protein research, or proteomics — is designed to test and identify biological agents in circumstances where commanders might have no idea what sort of threat they face. The system searches out the unique proteins in a sample, then identifies a virus or other microscopic life form based on the proteins it is known to contain.
Mysteries solved, knowledge gained, software developed: lots of good news there.
Now we just have to use the information to help the bees!