Canada has been suffering unusually high losses of bees each winter since 2006. That’s the year when a new and unexplained set of symptoms called Colony Collapse Disorder (CCD) began to be recognized. The impact to the hive colony was the large-scale disappearance of the worker bees.
Very high commercial honeybee losses have continued since then, with 30.9% of hives lost in Canada in 2010/11. This doesn’t include the serious decline of wild bees or other pollinators. Various infectious organisms, including two species of fungus from the genus Nosema, have received most of the blame; but taken alone they do not account for the symptoms of CCD.