Colony Collapse Disorder (or CCD) is a poorly understood phenomenon in which worker bees from a beehive or Western honey bee colony abruptly disappear. While such disappearance has a long-standing history of occurring, the term Colony Collapse Disorder was originally applied to perceived disappearances of Western honey bee colonies in a minority of regions of North America in late 2006.^[1]

Honey bees entering a beehive.

European beekeepers observed a similar phenomenon in Belgium, France, the Netherlands, Greece, Italy, Portugal, and Spain,^[2] and initial reports have also come in from Switzerland and Germany, albeit to a lesser degree.^[3] Possible cases of CCD have also been reported in Taiwan since April 2007.^[4]

The cause or causes of the syndrome are not yet well understood. Proposed causes include environmental change-related stresses,^[5] malnutrition, pathogens (i.e., disease^[6] including Israel acute paralysis virus^[7][8]), mites, pesticides such as neonicotinoids or imidacloprid, and genetically modified (GM) crops with pest control characteristics such as transgenic maize.^[9][10]