by D. Larraine Andrews

This spring Canadian beekeepers were on the alert for a potential new threat to their colonies called colony collapse disorder. The mysterious illness, which decimates the worker bee population in the hive, was responsible for the collapse of thousands of colonies across the United States.

Paul Laflamme, unit leader with the pest management systems group at Alberta Agriculture and Food, reports that to date there have been no reported cases of CCD in Canada.

A survey this summer of Alberta beekeepers showed that over-wintering losses, which are normally about 15 per cent, were almost double that amount this past winter. Laflamme says there were a number of factors that combined to produce this result, but CCD was not one of them.

A major factor was a longer than normal winter with early snow and a cool wet spring. This delayed flowering as much as three weeks and limited foraging sources. Another cause of the high losses was the failure of varroa mite treatments that were not as effective as hoped.

Now a consortium of researchers in the U.S. has found a significant connection between the Israeli acute paralysis virus and CCD. Bees imported from Australia are being implicated as a source of the virus.

Laflamme says that Australian bees have been imported into Canada for over twenty years with no serious problems. “Now we know a possible cause (for CCD) we can investigate if the bees have any potential to carry the virus.”

He points out that the Canadian climate is so different from the U.S. that the disease may not manifest itself in the same form. He adds that anecdotal evidence suggests that Australian bees do not over-winter as well in Canadian hives.

This spring, [Alberta] provincial apiculturist Medhat Nasr collected samples from colonies with high over-wintering losses for analysis. His article on best management practices appears in the August issue of Alberta Bee News published by the Alberta Beekeepers Association. Check the website at www.albertabeekeepers.org.

Source:
AgriSuccess Express (Farm Credit Canada)
21 September 2007

See also:
Alberta Winter Kill: Nature Buzzes Bees
Agri-News (Government of Alberta)
20 August 2007