Bee Colony Disorder

Colony Collapse Disorder (CCD) is a serious problem threatening the health of honey bees and the economic stability of commercial beekeeping and pollination operations in the United States. Despite a number of claims in the general and scientific media, a cause or causes of CCD have not been identified by researchers. U.S. Dept. of Agriculture

CCD History In October 2006, some beekeepers began reporting losses of 30-90 percent of their hives. While colony losses are not unexpected, especially over the winter, this magnitude of losses was unusually high. The main symptom of CCD is very low or no adult honey bees present in the hive but with a live queen and no dead honey bee bodies present. Often there is still honey in the hive, and immature bees (brood) are present. Varroa mites, a virus-transmitting parasite of honey bees, have frequently been found in hives hit by CCD.

This is not the first time that beekeepers are being faced with unexplained losses. The scientific literature has several mentions of honey bee disappearances—in the 1880s, the 1920s, and the 1960s. While the descriptions sound similar to CCD, there is no way to know for sure if those problems were caused by the same agents as CCD. There have also been unusual colony losses before. In 1903, in the Cache Valley in Utah, 2000 colonies were lost to an unknown "disappearing disease" after a "hard winter and a cold spring." More recently, in 1995-96, Pennsylvania beekeepers lost 53 percent of their colonies without a specific identifiable cause.

Dead bees don’t necessarily mean CCD Certain pesticides are harmful to bees. That’s why we require instructions for protecting bees on the labels of pesticides that are known to be particularly harmful to bees. This is one of many reasons why everyone must read and follow pesticide label instructions. When most or all of the bees in a hive are killed by overexposure to a pesticide, we call that a beekill incident resulting from acute pesticide poisoning. But acute pesticide poisoning of a hive is very different from CCD and is almost always avoidable. Environmental Protection Agency

Why it’s happening There have been many theories about the cause of CCD, but the researchers who are leading the effort to find out why are now focused on these factors: increased losses due to the invasive varroa mite (a pest of honeybees); new or emerging diseases such as Israeli Acute Paralysis virus and the gut parasite Nosema; pesticide poisoning through exposure to pesticides applied to crops or for in-hive insect or mite control; bee management stress; foraging habitat modification inadequate forage/poor nutrition and potential immune-suppressing stress on bees caused by one or a combination of factors identified above. Environmental Protection Agency

The Economist and Jeff Pettis Climate change, habitat destruction, pesticides and disease have all been suggested as possible causes. Nothing, though, has been proved. But the latest idea, reported in Naturwissenschaften by Jeff Pettis of the Bee Research Laboratory in Beltsville, Maryland, suggests that this may be because more than one factor is involved.

Pesticide called imidacloprid Dr Pettis and his colleagues knew from previous reports that exposure to a pesticide called imidacloprid has a bad effect on honeybees' ability to learn things and wondered whether it might be causing other, less noticeable, damage. Since one thing common to colonies that go on to collapse seems to be a greater variety and higher load of parasites and pathogens than other colonies, they wondered in particular whether it might be weakening the insects' immune systems, and thus allowing infections to spread through a hive.

Exposure to pesticide called imidacloprid Both of the groups that had been exposed to imidacloprid harboured an average of 700,000 parasite spores in each bee. Bees from the control colonies, by contrast, harboured fewer than 200,000 spores in their bodies. The insecticide, in other words, was exposing bees to infestation, and thus to a much greater chance of dying prematurely.

Would you apply the precautionary principle to imidacloprid? Yes No Do not know