[Updated Dec. 9] – Several years ago when neonicotinoids were linked to bee and other pollinator deaths sparking calls to ban the insecticides, farmers and neonicotinoid makers strongly defended them.
Now those products are under fire again due to their effect on aquatic insect life.
Health Canada announced Nov. 23 plans to phase out imidacloprid (the active ingredient in Gaucho), in three to five years, but in the meantime will consult for 90 days on possible mitigation measures before making a final decision.
Health Canada also announced “special reviews” of two other neonicotinoids — clothianidin and thiamethoxam — both of which are used more frequently than imidacloprid, mostly in seed treatments.
So far farmers’ response has been muted, but companies are still defending their products.
Bayer is “extremely disappointed” with Health Canada’s proposal to phase out imidacloprid, Derrick Rozdeba, Bayer CropScience’s vice-president of communications, said in an email.
“We will conduct a thorough review of its proposal and supporting data, and provide input into the consultation process,” he wrote.
“Canadian growers value neonicotinoids such as clothianidin and imidacloprid due to their efficacy, safety to applicators and favourable environmental profile, when used according to label instructions. Bayer will support Canadian growers’ use of these valuable tools by continuing to provide Health Canada with sound, science-based evidence concerning neonicotinoid’s favourable environmental profile, including respecting aquatic invertebrates.”
Syngenta isn’t aware of the information that sparked Health Canada’s special review of thiamethoxam and therefore can’t comment, Chris Davison, Syngenta’s head of corporate affairs in Canada, said in an email.
“That said, we will use the special review as another opportunity to bring all of the science to bear that supports the registration and safe use of thiamethoxam,” he wrote.
CropLife Canada, which represents, pesticide companies, hopes Health Canada will collaborate with stakeholders during the special reviews “to ensure that decisions are reached that give farmers access to the tools they need while providing the necessary protection for human and environmental health,” Pierre Petelle, CropLife’s vice-president of chemistry, said in an email. “Any decision on these products should be made in consultation with U.S. Environmental Protection Agency so that growers in Canada are not put at a competitive disadvantage to their counterparts in the U.S.”
Bee deaths linked to neonicotinoids dropped dramatically after the pest management Review Agency ordered several changes in 2014, including the adoption of a new dust-free, flow lubricant, when planting corn or soybean seed treated with neonicotinoid insecticides.
Mark Brock, chairman of Grain Farmers of Ontario, said his group accepts Health Canada’s science-based decision on imidacloprid.
“Its loss will have an impact on grain farmers but it’s the lesser used product of the three,” he said. “We need to focus on preserving the other two.”
Health Canada says the current investigation process is necessary.
“These special reviews will examine any potential risks these pesticides (clothianidin and thiamethoxam) may pose to aquatic invertebrates, including insects, as they are also being detected frequently in aquatic environments,” Health Canada said in a news release.
Imidacloprid use “is not sustainable, and the levels of this pesticide that are being found in waterways and aquatic environments are harmful to aquatic insects, such as mayflies and midges, which are important food sources for fish, birds and other animals.
“Health Canada has determined that concentrations of imidacloprid in surface water can range from non-detectable to, in some rare cases, levels as high as 11.9 parts per billion. Scientific evidence indicates that levels above 0.041 parts per billion are a concern.”
Health Canada acknowledged that for a few crops imidacloprid is the only approved insecticide for specific pests, and it has value as a seed treatment due to the “limited number” of registered seed treatments to manage the same pest and site combinations.
However, it noted, new insecticides have been submitted for approval and could serve as replacements in some cases, and label uses could possibly be expanded in other currently registered products.
What Health Canada found with imidacloprid triggered its “special review” of clothianidin and thiamethoxam.
Clothianidin is the active ingredient in Bayer CropScience’s Prosper, Poncho and Titan. Prosper is used to treat canola seed. Poncho is a corn seed treatment and Titan is used used on seed potato.
Thiamethoxam is the active ingredient in Syngenta’s Cruiser Maxx, used on wheat seed, and Helix, used on canola seed.