Despite years of research, no "smoking gun" has been identified as the cause of the syndrome known as colony collapse disorder (CCD) among the nation's honey bees. Reporting on colony health at the Almond Industry Conference in December after attending beekeeping conferences from coast to coast, Chris Heinz, the Almond Board's Bee Task Force Liaison, said CCD is likely caused by a combination of factors.
There appear to be a number of primary stressors such as Varroa mite, poor nutrition, Nosema, pesticides, and management factors rendering colonies susceptible to secondary stressors, such as viruses, which are always there and infect already weakened bees.
Also reporting on colony health at the Pollination Update session at the Conference was Dennis vanEngelsdorp, apiarist for the Pennsylvania Department of Agriculture and a researcher at Penn State University. The mysterious bee disappearance may be caused by an "altruistic suicide," he said, when ailing honey bees, sensing they are carrying an infection, leave the hive and never return, to avoid spreading the disease throughout the colony.
"Beekeepers who are doing well are feeding protein, and controlling Varroa mites and Nosema," he said.