The phenomenon of Colony Collapse Disorder, or CCD for short, has been known since the 1990s. Colonies rapidly lose most of their adult bees, which leave the hives in order to die elsewhere. The few remaining bees show an unusual spectrum of bacterial and viral infections, or even parasite infestation and fungal diseases.. This especially worries apiarists, whose colonies have already been weakened by the winter. Although definite results are still to be published for the current season, some apiarists expect high winter losses: Up to one third of all honey bee colonies in Germany might not have survived last winter.
CCD is a very complex phenomenon, and scientists differ about the reasons: The loss of a honey bee colony is regarded as the result of different intertwined factors.
Dr. Dennis vanEngelsdorp, entomologist at the University of Maryland in Washington, regards the Varroa mite as the most dangerous threat to the European honey bee. The expert describes the battle against a Varroa infestation as the primary objective to reduce the risk of infections: “I’d get rid of the Varroa first.”
Another far-reaching factor regarding bee health is nutrition: Vast monocultures and “green deserts” do not supply insects with sufficient nutrients. “Honey bees need a varied diet of different pollen”, explains Dr. Heather Matilla from Wellesley College. A hungry, weak bee is susceptible to Varroa mites, viruses and diseases.As long as apiarists are willing to take the costs and the effort, winter losses can be compensated over the year, says Dr. Greg Hunt, honey bee expert at the Purdue University. But there is a need for a more sustainable solution.
At the same time, a new challenge might arise for beekeepers: many honey bee queens die off unexpectedly and rapidly, Matilla observed: “When I started working with bees 18 years ago, we’d replace living queens every two years,” she recalls. “Now queens die after half a summer. Nobody is really clear about why.”
Read the full article dealing with CCD
More on the research of Dennis van Engelsdorp, Heather Matilla und Greg Hunt.