When Allan Campbell opened his hives this spring, he expected a buzzing horde of bees to greet him. Instead, he found that four out of every five hives were filled with clumps of dead bees.

"It’s very de-motivational when you’re just cleaning up all this death," said Campbell, who owns a bee farm in Dauphin, Man., and heads the Manitoba Beekeepers Association. "For all the work you do, you’re no further ahead. You’re behind."

Manitoba lost 46 per cent of its honey bee colonies over the past winter, a record rate for the province that makes it the worst hit province in the country, according to a recently released report by the Canadian Association of Professional Apiculturists (CAPA).

But those devastating losses are just one part of a bleak picture across Canada. Nation-wide, the winter mortality rate rose to about 29 per cent of honey bee colonies, nearly double the deaths in the winter prior.

It’s a setback that is dashing hopes raised last year by a low national rate of honey bee deaths — 15 per cent. Beekeepers were optimistic that the low mortality might herald a return to the average and more manageable losses the industry used to see.

"Last year, we were hoping we were going to be going into a trend as a country toward lower losses," said Rhéal Lafrenière, Manitoba’s provincial apiarist and the president of CAPA.

A 15 per cent loss rate used to be the average and is considered an acceptable percentage of bees left dead or unproductive over the winter period. That’s changed in the past decade as the new norm has been closer to 25 per cent, says Lafrenière.

"It’s getting to a point where we’re getting used to these higher losses."

Taking a bite out of bee health

Nearly every province experienced higher honey bee losses during the 2012-2013 winter compared to the one prior, with the exception of British Columbia and Nova Scotia, according to the report, which is based on surveys of beekeepers across the country.

Aside from Manitoba, the other provinces with the highest deaths were Ontario at just under 40 per cent, more than triple the loss figure of the previous year, and New Brunswick at 37 per cent this year, compared to 28 the year before.

Honey bee winter losses Province Winter 2011-2012 Winter 2012-2013 B.C. 27% 18% Alta. 13% 23.8% Sask. 17% 27% Man. 16% 46.4% Ont. 12% 37.9% Que. 16% 24% N.B. 27.9% 37.4% N.S. 18.9% 17% P.E.I. 19% 27.9% Canada 15.3% 28.6% Source: Canadian Association of Professional Apiculturists

While a lengthy winter and cold spring was at the root of the problem for many beekeepers, relentless parasites such as Varroa mites, which suck blood from bees, are also weakening and killing infested colonies.

Added stress to honey bee health from pesticides is also a growing concern. While "fugitive dust" coming from insecticides on corn seeds has been documented in Quebec since 2009 and is a known issue in Europe, Ontario saw high numbers of bee deaths tied to insecticides in the past year.

That has triggered calls for action to deal with the new and troubling threat to bee populations.

"We have all these individual stresses and on their own they each take a bite out of the bee’s health," said Lafrenière, but together the factors compound to kill more bees than they might have on their own.

Canada’s not alone in its bee plight.

In the United States, preliminary figures put their honey bee colony death rates at 31 per cent of the population, while Britain saw a slightly higher rate of nearly 34 per cent, the highest loss on record. Some fear those early numbers hide an even more troubling picture.

Critical to get handle on diseases

It’s hard to put an exact figure on how much the bee industry's struggles will cost the economy.

Canada is the world’s 12th largest producer of honey, with annual production valued at around $150 million. Beyond that, an increasing number of crops rely on bees for pollination, the value of which is estimated to be nearly $2 billion.

Tough times for beekeepers drive up costs of honey for consumers, but can also lead to lower crop yields.

"It’s frustrating to me that we’re still seeing these kinds of losses," said Rob Currie, an entomologist and University of Manitoba professor. "It’s really critical that we get a handle on these diseases and how they’re impacting colonies."

Currie said the high levels of loss are becoming more common and that beekeepers are finding it harder and harder to manage the biggest risks — parasites and diseases.

To some degree, beekeepers are adjusting to the new high loss levels by rearing extra bees in the summer to make up for winter losses and buying packages of bees in the spring from New Zealand, Australia and Chile. But it’s not always enough to counter the continuously high death rates.

Work is underway to try to document the myriad of causes killing bees and how they interact with each other, but also to breed bees that are more resistant to parasitic mites and diseases.

Campbell, who spent more than six weeks cleaning up dead beehives, is now focusing on his next winter. He hopes it won’t be as bad as the last.

"It’s definitely getting harder to keep bees alive," he said. "You’re just constantly trying to figure out: Did you do something wrong? Was it this or was it that? It’s pretty hard to connect the dots."

A 'senseless,' costly ban

While scientists and beekeepers alike grapple to find answers, Campbell and others are lobbying the federal government to lift a decades-old restriction on buying bees from American suppliers that forces farmers to purchase more expensive bees from abroad.

The ban on buying bees from the continental U.S. came into effect in 1987 after an outbreak of Varroa mites in the United States.

Whereas a one-kilogram package of bees and a queen bee cost upwards of $150 from New Zealand or Australia, the same can be purchased for less than $60 from Florida, a huge savings when a farm faces massive losses like this past winter, says Campbell.

The Manitoba apiarist calls it a "senseless political ban" considering the highly migratory nature of bees and hopes the ban will be lifted by next summer. The federal government says a risk assessment is underway. It's unknown when it will be completed.

"We're still waiting and hoping on this risk assessment," said Campbell. "If we can’t figure out what’s happening, at least we can have access to replacement bees."