Canadians beekeepers, farmers and regulators are wrestling with how to protect bees from  popular pesticides that were partially banned in Europe this week.

The European Commission announced Monday that it would go ahead with a partial two-year ban on three kinds of neonicotinoid pesticides that have been linked to bee deaths. The pesticides are used to coat most commercial corn seeds and protect them from pests such as seed-eating insects.

Canadian government scientists have found evidence that neonicotinoid pesticides were linked to mass bee deaths during the spring corn planting in Ontario and Quebec in 2012, Health Canada's Pest Management Regulatory Agency confirmed in a report.

To ban or not to ban?

That has some people, such as Dan Davidson, president of the Ontario Beekepers' Association, calling for the use of the neonicotinoid pesticides to be restricted in Canada also.

"I think the best for beekeepers would be a ban," he told CBC's The Current. "We have to call for replacement of these chemicals. We won't be able to keep going on if they continue to be used at the rates they're being used now."

The environmental advocacy group Sierra Club Canada is similarly calling for a Canada to take the pesticides off the market until they have been proven safe.

However, Kevin Armstrong, a farmer who grows corn, wheat and soybean south of Woodstock, Ont., said neonicotinoid pesticides are essential for protecting corn seeds and seedlings during their crucial first month.

"It is a kind of insurance policy for us," he told The Current. "The vigour of the whole plant is assured for the whole season."

Armstrong said neonicotinoids are largely responsible for a 15 per cent increase in Ontario corn yields over the past 15 years, and so a ban on them could cause a significant loss. A loss of 10 per cent translates into about $100 an acre, he said. If Ontario farmers plant 2.3 million acres of corn as expected, that could amount to a $230-million loss.

"It works out to a significant economic setback for us."

2012 mass deaths unprecedented

Mary Mitchell, director-general of the environmental assessment directorate with Health Canada's Pest Management Regulatory Agency, said neonicotinoid pesticides have been registered in Canada for 10 to 15 years and mass bee deaths linked to them had never been reported before last year.

"So we do think the weather may have been a factor," she said, noting that it had been an unusually early, warm dry spring.

She said regulators are working to prevent that happening again, but she did not mention any talk of restrictions on the use of the pesticides.

Instead, she said the government is encouraging farmers to communicate better with beekeepers and to using planting equipment that minimizes the production of dust, which is thought to be a major way bees are exposed to the pesticides.

The government is also working with the agricultural industry on ways to get the pesticide coating to stick better to the seed so it can't come off and harm the bees.

Tracy Baute, who leads the field crop entomology program at the Ontario Ministry of Agriculture and Food, said more studies are underway to find out exactly how bees are exposed to neonicotinoid pesticides.

However, in the meantime, she recommends that farmers:

  • Let nearby beekeepers know when they are planting so the beekeepers can move hives if necessary.
  • Consider planting in the early morning or the evening, when bees are less active.
  • Consider using seeds that aren't treated with pesticides in fields at a lower risk of attack by pests.

The reports of mass bee deaths in Ontario and Quebec in 2012 took place around the time that two scientific studies were published showing that bees can be harmed by even low levels of neonicotinoids.

Many bee species have been declining in North America and Europe, and some have even gone extinct or are believed to be close to extinction. Meanwhile, honeybees have been reported dying or disappearing en masse since 2006. In addition to pesticides, there is evidence that fungi, viruses, or parasites may play a role.