This spring most Canadian corn and soybean growers will be planting another crop of pesticide-coated seeds, even as researchers raise new warnings that the practice may have deadly side effects for bees and other wildlife.
The heated debate around the use of the neonicotinoid-coated seeds, developed by Bayer CropScience and introduced here about a decade ago, has divided farmers, beekeepers and scientists, and turned Canada into a kind of environmental battlefront.
To protect its bees, Europe banned the use of neonic pesticides last year, while U.S. authorities have so far taken a more cautious approach, saying these pesticides are just one possible factor in the collapse of so many bee colonies. Bayer filed a court challenge against the EU ban in August last year, saying the EU has wrongly linked the pesticide to bee deaths.
Bayer and Health Canada maintain that proper planting practices minimize the risk to bees, while others say use of neonics should be suspended until the questions being raised by researchers and beekeepers have been answered.
Over the past few years, neonicotinoids have become the dominant insecticide in everything from corn and canola to flea collars for pets.
But some believe this insecticide, particularly the version that coats the seeds and protects the plant as it matures, is responsible for the decline in honey bees.
When Health Canada tested dead bees last spring it found neonicotinoid on 70 per cent of them. At the time, it was thought the bees had become exposed to the dust that's kicked up during the planting process.
"Current agricultural practices related to the use of neonicotinoid-treated corn and soybean seed are not sustainable due to their impacts on bees and other pollinators," Health Canada then declared in a statement dated Sept. 13, 2013.
To address the dust concern, Health Canada's pesticide regulatory agency and the makers of the insecticide developed new best practices guidelines for farmers to go into effect this spring.
As part of the initiative, Bayer introduced a new lubricant that its lab tests suggest will help the treated corn seed flow through the planter, reducing total dust by 90 per cent and the active ingredient by 40 to 70 per cent.
Bayer told the CBC: "The new fluency agent has been shown to dramatically reduce dust when compared to the current industry standard lubricants."
But when the Ontario Ministry of Agriculture and Food tested the new lubricant under field conditions, it found dust was still problematic. OMAF field crop entomologist Tracey Baute says, "the lubricant, the fluency agency, does reduce the amount of active ingredient in the dust by 21 per cent."
"We're still trying to determine if a balance can be made in the use of these products and protecting the pollinators," Baute adds.
Veteran Ontario beekeeper Tibor Szabo Jr. is not impressed. "A 21 per cent reduction of something that's very, very toxic isn't going to make me feel better," he says. "Do I think it's going to save the bees? Heck no.
"There's a heck of a lot more to this than dust."
Indeed now some researchers are saying that dust from planting could be just part of a bigger issue with neonics.
Canadian environmental scientist Madeleine Chagnon has spent the past 20 years studying honey bees.
When she analyzed dead bees she discovered a bio-marker that suggested the bees had come into contact with neonicotinoids whether they had been exposed to planting dust or not. This suggests that they were exposed to the pesticide while collecting pollen from maturing plants, says Chagnon.
"They're taking in something that they will ultimately die from, and they're taking this into the hive and feeding on it all winter, then we wonder why we have winter mortality."
For Chagnon, this means no amount of dust-reducing agents, better communication or labelling will prevent what is happening to honey bees. She's pushing for neonic products to be banned.