http://www.digitaljournal.com/article/292966

Still a mystery why honey bee die-off continues

Posted Jun 4, 2010 by Martin Laine
It’s been nearly four years since beekeepers around the country began reporting unusually high losses of otherwise healthy hives. Adding to the mystery, the hives were abandoned, leaving behind honeycombs, immature bees, and occasionally a live queen.
honey bees
honey bees
Known as Colony Collapse Disorder, no single cause has yet been found. The most recent thinking is that it may be a combination of factors.
Meanwhile, the loss of hives continues to worsen. A report released by the United States Dept. Of Agriculture in April shows that 34 percent of managed hives were lost between October 2009 and April 2010. For the same period the previous year, a 29 percent loss was reported.
The implications of the problem go far beyond a threat to the honey supply. Nearly 80 percent of the fruits and vegetables Americans eat need to be pollinated. So far, the loss of hives hasn’t significantly impacted food production, other than a rise in the cost of bringing in bees to pollinate crops. That could change if the loss continues.
The USDA lists several possible reasons for the disorder.
The widespread use of pesticides has long been looked at as a prime suspect, but research on affected colonies hasn’t found a definite link for all cases. One possibility is that there may be an as-yet undiscovered consequence.
Commercial beekeeping operations may be creating stresses for the bees, caused by crowded conditions, the stress of being transported from one place to another, possibly poor nutrition from the plants they’re expected to pollinate.
There are also indications that some parasites are present, and they may cause more harm if the health of a colony is already compromised from other factors.
Last month, at the meeting of the American Society for Microbiology in San Diego, USDA researchers outlined a new possibility – that a fungus and a group of viruses may have joined forces causing the disorder.
“There may be a synergism between two very different pathogens,” said Jay Evans, one of the researchers. “When they show up together, there is a significant correlation with colony decline.”
By identifying possible causes, beekeepers can begin taking steps to protect their hives. In the meantime, beekeepers are being advised to keep their hives healthy by reducing some of the stress factors and trying to minimize exposure to pesticides.