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Colony collapse disorder (CCD) is the phenomenon that occurs when the majority of worker bees in a colony disappear and leave behind a queen, plenty of food and a few nurse bees to care for the remaining immature bees and the queen. While such disappearances have occurred throughout the history of apiculture, and were known by various names (disappearing disease, spring dwindle, May disease, autumn collapse, and fall dwindle disease), the syndrome was renamed colony collapse disorder in late 2006 in conjunction with a drastic rise in the number of disappearances of western honeybee (''Apis mellifera'') colonies in North America. European beekeepers observed similar phenomena in Belgium, France, the Netherlands, Greece, Italy, Portugal, and Spain,〔Gaëlle Dupont, (Les abeilles malades de l'homme ), ''Le Monde'', 29 August 2007 .〕 Switzerland and Germany, albeit to a lesser degree, and the Northern Ireland Assembly received reports of a decline greater than 50%. Colony collapse disorder causes significant economic losses because many agricultural crops (although no staple foods) worldwide are pollinated by western honey bees. According to the Agriculture and Consumer Protection Department of the Food and Agriculture Organization of the United Nations, the worth of global crops with honeybee’s pollination was estimated to be close to $200 billion in 2005.〔(Spotlight: Protecting the pollinators ). Fao.org. Retrieved on 2014-04-12.〕 Shortages of bees in the US have increased the cost to farmers renting them for pollination services by up to 20%. In the six years leading up to 2013, more than 10 million beehives were lost, often to CCD,〔 nearly twice the normal rate of loss. Several possible causes for CCD have been proposed, but no single proposal has gained widespread acceptance among the scientific community. A large amount of speculation has surrounded a recently introduced family of pesticides called neonicotinoids as having caused CCD. Other suggested causes include: infections with ''Varroa'' and ''Acarapis'' mites; malnutrition; various pathogens; genetic factors; immunodeficiencies; loss of habitat; changing beekeeping practices; or a combination of factors. == History == Limited occurrences resembling CCD have been documented as early as 1869 and this set of symptoms has, in the past several decades, been given many different names (disappearing disease, spring dwindle, May disease, autumn collapse, and fall dwindle disease).〔 Most recently, a similar phenomenon in the winter of 2004/2005 occurred, and was attributed to varroa mites (the "vampire mite" scare), though this was never ultimately confirmed. The cause of the appearance of this syndrome has never been determined. Upon recognition that the syndrome does not seem to be seasonally restricted, and that it may not be a "disease" in the standard sense—that there may not be a specific causative agent—the syndrome was renamed.〔 A well-documented outbreak of colony losses spread from the Isle of Wight to the rest of the UK in 1906. These losses later were attributed to a combination of factors, including adverse weather, intensive apiculture leading to inadequate forage, and a new infection, the chronic bee paralysis virus, 〔()〕 but at the time, the cause of this agricultural beekeeping problem was similarly mysterious and unknown. Reports show this behavior in hives in the US in 1918 and 1919. Coined "mystery disease" by some, it eventually became more widely known as "disappearing disease". Oertel, in 1965, reported that hives afflicted with disappearing disease in Louisiana had plenty of honey in the combs, although few or no bees were present, discrediting reports that attributed the disappearances to lack of food. From 1972 to 2006, dramatic reductions continued in the number of feral honey bees in the U.S. and a significant though somewhat gradual decline in the number of colonies maintained by beekeepers. This decline includes the cumulative losses from all factors, such as urbanization, pesticide use, tracheal and ''Varroa'' mites, and commercial beekeepers' retiring and going out of business. However, in late 2006 and early 2007, the rate of attrition was alleged to have reached new proportions, and the term "colony collapse disorder" began to be used to describe this sudden rash of disappearances (sometimes referred to as "spontaneous hive collapse" or the "Mary Celeste syndrome" in the United Kingdom).〔 Losses had remained stable since the 1990s at 17%–20% per year attributable to a variety of factors, such as mites, diseases, and management stress. The first report of CCD was in mid-November 2006 by a Pennsylvania beekeeper overwintering in Florida. By February 2007, large commercial migratory beekeepers in several states had reported heavy losses associated with CCD. Their reports of losses varied widely, ranging from 30% to 90% of their bee colonies; in some cases, beekeepers reported losses of nearly all of their colonies with surviving colonies so weakened that they might no longer be able to pollinate or produce honey. Losses were reported in migratory operations wintering in California, Florida, Oklahoma, and Texas. In late February, some larger nonmigratory beekeepers in the mid-Atlantic and Pacific Northwest regions also reported significant losses of more than 50%. Colony losses also were reported in five Canadian provinces, several European countries, and countries in South and Central America and Asia. In 2010, the USDA reported that data on overall honey bee losses for 2010 indicated an estimated 34% loss, which is statistically similar to losses reported in 2007, 2008, and 2009.〔 Fewer colony losses occurred in the U.S. over the winter of 2013-2014 than in recent years. Total losses of managed honey bee colonies from all causes were 23.2% nationwide, a marked improvement over the 30.5% loss reported for the winter of 2012-2013 and the eight-year average loss of 29.6%. After bee populations dropped 23% in the winter of 2013, the Environmental Protection Agency and Department of Agriculture formed a task force to address the issue. In the six years leading up to 2013, more than 10 million beehives were lost, often to CCD, nearly twice the normal rate of loss. However, the total number of beehives worldwide continues to grow ((Bee population rising around the world )). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「colony collapse disorder」の詳細全文を読む スポンサード リンク
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