Honeybees have become celebrities of the insect world, beloved for their vital role as pollinators and pitied for being victims of “colony collapse” – an epidemic of mass bee deaths that has caused their populations in North America to dwindle.
Lost in much of the honeybee discourse is the fact that they are not native to North America. They come from warmer climates in Southern Europe, Northern Africa and parts of Asia, and were brought to this continent in the 17th century for use as agricultural pollinators and honey producers. As farming developed into an industrialized business, the sector came to depend on the services of the European honeybee, which excels at living, feeding and pollinating in large groups.
Now, as those bees struggle to survive, some experts say the crisis may have a relatively straightforward solution: supplement those imported bees with members of Canada’s more than 860 native bee species, whose ancestors were flitting from flower to flower in this part of the world long before the first honeybee hive came on the scene.
The first of the recent wave of large honeybee losses in North America happened in 2007 and 2008. Until that point in time, beekeepers had been accustomed to seeing about 10 per cent of their bees die in a typical season. Suddenly they were noticing losses of more than 30 per cent.
Paul Kelly, research and apiary manager at the University of Guelph’s honeybee research centre, said the resulting spike in public concern over the fate of honeybees has frequently overshadowed the importance of native pollinators.
“We’ve always considered beekeeping as an agricultural activity, but when we started to see a jump in colony losses, it got people’s attention,” he said. “The beekeeping community was kind of taken off guard by that. We were just trying to do our thing in agriculture, and lots of other people piled on and pursued it as an environmental issue, not realizing these weren’t native species. Things got kind of muddy from there.”
”Honeybees have habitats, they have funding, they have vital research happening that is constantly evolving because they’re part of our economy,” he added. “They have a strong support system. But native bees, they’re kind of on their own.”
The same collectivity that makes honeybees so effective as pollinators can also be their downfall, because pests, diseases and pesticide exposure can spread quickly among them. This year, it’s not only a wing-deforming parasite, Varroa destructor, that is to blame for honeybee losses, but also the effects of this past long, cold winter. Even less severe Canadian winters can be hard on European honeybees.
Despite colony collapse, there are more honeybees being managed by beekeepers in Canada today than ever before, in part because the number of bees has risen to meet demand. Some of the rise is also attributable to the fact that the bees are not as productive as they used to be. Explanations for this include a reduction in the variety of food sources available to them, brought about by intense monocropping, where a farmer plants a large expanse of a single crop as a way of maximizing production. And bee productivity can also be affected by stress that occurs when farmers move colonies from location to location.
Native bee species are capable of meeting some of farms’ pollination demand, experts believe, but only if the mix of plants being grown is adapted so that the bees can feed throughout the summer, rather than only when cash crops are in bloom.
“Bumblebees co-evolved with native crops, like blueberries as well as cranberries, in the northern hemisphere over millions of years, so they are superbly effective at pollinating these cash crops,” said Paul van Westendorp, British Columbia’s provincial apiculturist. But blueberries flower only for about a month in the spring, he added, so native bees can’t survive on that nectar alone.
“Beekeepers will just pick up and move their honeybees out, and take them to another area where there is a new nectar source to pollinate. But our wild pollinators, they cannot move.”
A more bee-friendly mix of crops could extend the feeding period for native pollinators and help them survive and reproduce. And farmers could improve matters further by lining fields with native plants specifically for the bees to feed on, Mr. van Westendorp suggested.
“The recommendation that we have been making to growers, to land managers, to municipalities, is to plant more plants that provide nectar and pollen for all the pollinators. Not ones that just flower all at once, but a mixture of native floral sources that offer a variety of nectar and pollen sources from May all the way up to September to October.”
Supplementing spaces with diverse plant species could benefit both native bees and honeybees, because the latter would gain access to a wider variety of food sources. And landscapes could also benefit from the change, because a mix of plants with different tolerances for adverse conditions would be more resistant to unexpected environmental changes, like droughts or floods.
“Diversity is nature’s insurance policy, and that’s how nature does it naturally,” said Megan Evans, president of the Alberta Native Bee Council.
“There has actually been research done, based in Canada, that shows various scenarios where you could take part of your land out of crop and instead put in pollinator habitat and diverse plants, and it would actually result in higher yield, because you would have all of these different elements offering ecosystem services.”
Ms. Evans argued that inaction could eventually force change on the agriculture industry. “If losses continue growing, and our practices don’t shift, there could come a time where the use of honeybees becomes so cost prohibitive that we simply couldn’t afford to use them anymore,” she said.
Even in Canada’s landscapes as they currently exist, native bees do vital work. Different bee populations pollinate different plants at different times, which ensures access to a variety of food sources for many animal species, including humans.
Honeybees may be good for fulfilling the country’s short-term agricultural needs, but a long-term strategy that bolsters native species could yield benefits far into the future.
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