Prairie beekeepers continue to struggle with escalating winter losses in their honeybee stocks.
In Saskatchewan, chief apiculturist John Gruszka said colony losses during the winter of 2008-09 will probably average 25 to 30 percent.
A recent survey of 20,000 colonies in the province suggests losses in the 29 percent range.
Normally, a survey of 30,000 or 40,000 colonies is required to obtain an accurate read on provincial losses, he added.
Losses in the winter of 2007-08 were 24 percent.
“This year, losses were perhaps a bit heavier than they were last year because we had some really cold weather in March,” Gruszka said.
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“The night time temperatures were 30 below and that’s really hard on a colony that’s trying to raise young brood and keep their colony alive.”
Years ago, prairie beekeepers expected colony losses of 10 percent in a normal winter and 15 percent in a harsh winter.
However, loss rates have doubled in the last 20 years and in some cases tripled.
A major contributing factor is the proliferation of varroa and tracheal mites, pests that did not exist on the Prairies two decades ago.
“Over the last three years, we’ve had some pockets of very heavy losses,” Gruszka said.
“We’ve got a few producers that have had 40, 50, 60 percent winter losses and for them, on an individual basis, that’s severe. That’s very extreme.”
In today’s market, the loss of a single bee colony could cost a producer as much as $500 in lost honey production, increased labour costs and expenses related to restocking.
For a producer with 1,000 colonies, a 50 percent winter loss would represent a financial hit of roughly $250,000.
“That’s a significant cost,” Gruszka said. “It’s not easy to recover from.”
He said prairie producers are still on a steep learning curve when it comes to dealing with mites, but they are becoming more vigilant in monitoring for the parasites and treating infected colonies.
Another complication is that an increasing number of mites have developed resistance to commonly used chemical treatments.
An application has been made to the Pest Management Regulatory Agency seeking an extension of emergency registration on a new treatment called Apivar.
Producers eagerly awaited its arrival last year, but it didn’t arrive until late in the season, too late for most.
In Manitoba, producers who used Apivar reported good results, said provincial apiarist Rheal Lafreniere.
Producers who wintered their colonies indoors also reported lower losses, he said.
Preliminary results from a survey of Manitoba beekeepers suggest that average colony losses will be 25 percent.
“On the long-term scale, that’s still pretty high but this year … we’re actually predicting a bit lower losses than the last two years, which were much closer to that 30 percent range,” Lafreniere said.
Manitoba’s cold winter and a relatively late spring are adding extra stress to colonies, which need warm weather and access to natural pollens to repopulate.
“Generally at this point in time, the colonies are really starting to repopulate,” he said.
“Under the conditions that we’ve been getting weather wise, they haven’t really had an opportunity to do that … so we’re running a bit behind.”
