The buzz on honeybees in Canada

By Gabriel Mayost

By many accounts, last year was a bad one for bees.

Reports of high winter colony losses garnered national attention, with 25 per cent of Canadian honeybee colonies reported as dead or unproductive come spring. Particularly troubling was the 58 per cent wintering loss recorded in Ontario, whose government sets acceptable wintering losses at 15 per cent.

But surprisingly, by the fall, Statistics Canada reported that the number of bee colonies in Ontario had actually increased, from 100,000 to 112,800.

“Colony numbers are actually not doing too bad,” says Paul Kelly, the Research and Apiary Manager at the University of Guelph. He says that beekeepers will divide their surviving hives and purchase new queens to compensate for lost ones, although dividing hives this way usually incurs some loss in honey productivity.

But this isn’t to say that the outlook of apiculture is entirely rosy.

“Some of the rhetoric saying that we’re in crisis of losing all our colonies,” says Kelly. “That’s not true, but that doesn’t mean that there aren’t serious problems.”

“It’s fairly widely accepted in the scientific community that the issues with bees are a multifactorial problem,” says Rob Currie, an entomologist at the University of Manitoba.

“There’s a lot of dynamics that are very interwoven and complex,” echoes Kelly.“It’s really, really tough to separate all these different effects. They all kind of blend together, and they can be totally different five miles down the road.”

Outcries from the scientific community lead the media to identify neonicotinoids, or neonics, a kind of insecticide similar to nicotine, as the primary culprit.

Introduced to Ontario in 2004, neonic treatment was pushed because it wasn’t thought to be harmful to people or the insects it didn’t specifically target. By 2008, all corn seed from major companies in Ontario was coated with neonics.

At this point, there is little scientific doubt that neonics are harmful to bees. They can be toxic when they come into contact with bees through water and pollen. While their nonlethal effects are not completely understood, research shows that neonics interfere with bee behaviour by disrupting their nervous system.

Kelly says beekeepers are deeply concerned about pesticides because they have no control over how they interact with their colonies. He applauds the Ontario government’s plan to reduce the use of neonics by 80 per cent by 2017, but he says that there are other factors at play that are just as important.

“There are some serious problems with chemicals,” he says, “but there are also longstanding disease and parasite problems, which some years are more difficult to control than others.”

“I think if I had to name the number one problem,” says Currie, “it would be the varroa mite, and the various diseases and viruses that are linked to them.”

Introduced in Canada in 1991, the varroa is a species of mite that can only reproduce in bee hives. It attaches itself to bees and feeds on their hemolymph, which the equivalent of blood in insects. In the process, it introduces deadly viruses, such as the deformed wing virus, into the hive.

Although they were originally controlled by pesticides, varroa mites have since developed resistances to many pesticide treatments. According to a 2010 study from the University of Guelph, varroa mite infestations account for up to 85 per cent of winter colony mortality.

While Kelly says that beekeepers have the tools to ward off varroa mites most of the time, Currie says that there’s little they can to control the viruses they introduce.

“The viruses will still be present in high levels,” he says. “Although we not see mites in the hive, in many instances, they will still be responsible for causing the damages.”

When the issue of bee losses first came into play, scientists felt that the transportation of bees for the pollination of crops was a contributing factor, says Currie.

Colonies are loaned from Ontario to Quebec and the Maritimes, primarily to pollinate blueberry or cranberry crops. In 2013, 24,400 colonies were shipped from Ontario alone. Kelly estimates that the number will reach around 30,000 this year, because the financial opportunity is too great for many beekeepers to pass up.

  Although subsequent studies show no clear correlation between colony deaths and stationary or migratory beekeeping, Currie says the close quarters bees are kept in while traveling have an effect on the health of colonies.

“The actual act of moving the bees, although it is in no doubt stressful, may not be a major factor,” he says, “but I think what it does do is it results in the spread of diseases between hives across the country.”

Perhaps the most unpredictable factor is the weather. It affects how much forage is available to bees, and winter directly affects yearly bee populations.

Early and cold winters can tire bees out, says Kelly, but early springs can also give parasites a head start. As frigid as the past winter was, Kelly says that it could have been worse.

“We’ve a lot of really cold weather, but the year before, winter started much earlier than this year. It was longer and colder,” he says.

That’s a good sign, but he says it’s still too early to tell how the bees fared through the winter because of a delayed spring. He says it’s not good to poke around the hives until later in the spring when the bees are stronger.

“We’re still at an early stage, there can still be a lot of decline that happens over the next six weeks,” he says, “but hearing from beekeepers in Ontario that they’re relatively pleased with the amount of colonies that are alive.” 

Ontario isn’t the only province whose honeybee colonies are facing high winter mortality. Take a look at the graph below, where you can compare the provincial wintering losses of individual provinces using the filter. You can also check out the annual colony loss reports published by the Canadian Association of Professional Apiculturists here.

[Front page photo courtesy of Flickr]