A University of Guelph researcher, Professor Ernesto Guzman has identified a distinctly Canadian cause of honeybee hive die-off. In the United States hives are found empty in the spring, in Canada they are full of bee cadavers.
The phenomenon is called colony collapse disorder (CCD) in the U.S. and winter colony mortality in Canada.
In the United States researchers have focused on possible disruptions to the bees' global positioning systems that render them unable to return to the hive safely.
However, the Canadian situation is significantly difficult as the hives are not empty in the spring but rather, they are full of bees. However, the bees are all dead. This led researchers to ascribe a unique cause to the phenomenon of hive die-off in Canada:
Researchers at the University of Guelph studied more than 400 colonies throughout three seasons, and found that infestations of varroa mites were the leading cause of death.
The mites were associated with more than 85 per cent of colony deaths.
University of Guelph biologist Ernesto Guzman says the study looked at five different factors that could kill bees, and the researchers were able to determine which one carries the most weight.
With hives becoming active in warmer parts of Canada, the Canadian Broadcasting Corporation (CBC) reports that, "Vancouver Island beekeepers say 90 per cent of their hives have been wiped out by a lethal combination of disease and a long summer last year." The long summer last year meant a longer pollen gathering season which weakened the bees and left them more vulnerable to the Varroa mites.
At the same time the Varroa mites have been developing a resistance to the pesticides that are traditionally used to control them. Guzman " suspects varroa has adapted to pesticides. If so, a beekeeper may spray mite killer and think all is well, only to have the mites survive and wipe out the hive," the Ottawa Citizenreports.
According to Paul van Westendorp, the provincial apiculturist at the B.C. Ministry of Agriculture and Lands, the problem goes beyond just honey and has implications for all of our agricultural supplies, "in an agricultural context, what is important is crop pollination — no bees, no berries," and neither fruits nor vegetables one might add.