colony collapse disorder

Colony collapse disorder (CCD) or sometimes honey bee depopulation syndrome (HBDS) is a phenomenon in which worker bees from a beehive or European honey bee colony abruptly disappear. While such disappearances have occurred throughout the history of apiculture, the term colony collapse disorder was first applied to a drastic rise in the number of disappearances of Western honey bee colonies in North America in late 2006. Colony collapse is economically significant because many agricultural crops worldwide are pollinated by bees. European beekeepers observed similar phenomena in Belgium, France, the Netherlands, Greece, Italy, Portugal, and Spain, and initial reports have also come in from Switzerland and Germany, albeit to a lesser degree while the Northern Ireland Assembly receives reports of a decline greater than 50%. Possible cases of CCD have also been reported in Taiwan since April 2007.
The cause or causes of the syndrome are not yet fully understood, although many authorities attribute the problem to biotic factors such as Varroa mites and insect diseases (i.e., pathogens including Nosema apis and Israel acute paralysis virus). Other proposed causes include environmental change-related stresses, malnutrition and pesticides (e.g. neonicotinoids such as imidacloprid), and migratory beekeeping. More speculative possibilities have included both cell phone radiation and genetically modified (GM) crops with pest control characteristics, though experts say no evidence exists for either assertion. It has also been suggested that it may be due to a combination of many factors and that no single factor is the cause.
http://en.wikipedia.org/wiki/Colony_collapse_disorder