Colony collapse disorder (CCD) is an abnormal phenomenon that occurs when the majority of worker bees in a honey bee colony disappear, leaving behind a queen, plenty of food, and a few nurse bees to care for the remaining immature bees. While such disappearances have occurred sporadically throughout the history of apiculture, and have been known by various names (including disappearing disease, spring dwindle, May disease, autumn collapse, and fall dwindle disease), the syndrome was renamed colony collapse disorder in early 2007 in conjunction with a drastic rise in reports of disappearances of western honey bee (Apis mellifera) colonies in North America. Beekeepers in most European countries had observed a similar phenomenon since 1998, especially in Southern and Western Europe; the Northern Ireland Assembly received reports of a decline greater than 50%. The phenomenon became more global when it affected some Asian and African countries as well.
Colony collapse disorder could cause significant economic losses because many agricultural crops worldwide depend on pollination by western honey bees. According to the Agriculture and Consumer Protection Department of the United Nations' Food and Agriculture Organization (FAO), the total value of global crops pollinated by honey bees was estimated at nearly US$200 billion in 2005. In the United States, shortages of bees have increased the cost to farmers renting them for pollination services by up to 20%. Declining numbers of bees predate CCD by several decades, however: the US managed hive industry has been shrinking at a steady pace since 1961.
In contrast, the bee population worldwide has been increasing steadily since 1975, based on honey production, with China responsible for most of the growth. The period of time with the lowest growth in worldwide honey production was between 1991 and 1999, due to the economic collapse after the dissolution of communism in the former Soviet sphere of influence. As of 2020 the production has increased further by 50% compared to 2000, double the rate of growth in previous decades, notwithstanding CCD.
Several possible causes for CCD have been proposed, but no single proposal has gained widespread acceptance among the scientific community. Suggested causes include pesticides; infections with various pathogens, especially those transmitted by Varroa and Acarapis mites; malnutrition; genetic factors; immunodeficiencies; loss of habitat; changing beekeeping practices; or a combination of factors. A large amount of speculation has surrounded the contributions of the neonicotinoid family of pesticides to CCD, but many collapsing apiaries show no trace of neonicotinoids.
History
Colony collapse disorder is a syndrome defined by a specific set of symptoms which, in the past several decades, has been given many different names (among them "disappearing disease", "spring dwindle", "May disease", "autumn collapse", and "fall dwindle disease"). The cause of these symptoms has never been determined. Only very recently, 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 one specific causative agent or pathogenesis—was the syndrome renamed.
Limited occurrences resembling CCD were documented as early as 1869. A well-documented outbreak of colony losses spread from the Isle of Wight to the rest of the UK in 1906. These losses were later attributed to a combination of factors, including adverse weather, intensive apiculture leading to inadequate forage, Acarine (tracheal) mites, and a new infection, the chronic bee paralysis virus, but during the outbreak, the cause of this agricultural beekeeping problem was unknown.
Reports show similar 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.
In the US, the number of colonies maintained by beekeepers had been in decline since the 1960s, for various reasons including 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 people began to use the term colony collapse disorder to describe the sudden rash of disappearances (or sometimes spontaneous hive collapse or the Mary Celeste syndrome in the United Kingdom).