Researchers say they now have the first hard evidence of what is happening physiologically inside bees during Colony Collapse Disorder. Using a tool called a genome-wide microarray, researchers at the Agricultural Research Service and University of Illinois found a large amount of abnormal ribosomal RNA fragments in the guts of honey bees in CCD colonies. Ribosomes are the cellular factories in which proteins are made. The fragments indicate the protein construction system is compromised and honey bees in colonies diagnosed with CCD had reduced ability to synthesize new proteins.
Entomologist May Berenbaum believes the loss of ribosomal function would explain many of the phenomena associated with CCD. Berenbaum says if the bees' ribosomes are compromised, then they can't overcome exposure to pesticides, fungal infections or bacteria or inadequate nutrition because the ribosome is central to the survival of any organism.
Researchers say almost all CCD colonies tested had a higher level of picorna-like viruses, which attack the ribosome. Picorna-like viruses that attack honey bees include deformed wing virus and Israeli acute paralysis virus. The varroa mite, a major honey bee parasite, is known to transmit picorna-like viruses. Bees in CCD colonies did not show significantly active pesticide response genes.
The study did not establish a direct cause-and-effect link between the abnormal rRNA and CCD. But colony surveillance by assays of rRNA and other markers expressed by bees could provide the earliest indication of CCD found so far, perhaps in time for beekeepers to take actions that might reduce losses.