Neonics no threat, Guelph team says

Neonicitinoid seed-treatment pesticides are not a threat to honeybee colony survival, provided farmers use them correctly, say two University of Guelph researchers after reviewing available research studies.

The University of Guelph team, led by toxicologist Keith Solomon and adjunct professor Gladys Stephenson, analyzed 64 papers from “open, peer-reviewed literature” on the topic plus 170 unpublished studies submitted to regulators by the products’ manufacturers, Syngenta and Bayer.

The scientists, who on Monday published their findings the Journal of Toxicology and Environmental Health, said Bayer and Syngenta asked them to assess earlier studies conducted by or for the companies, on the impacts of pesticide-treated seeds on honeybees.

They used a “quantitative weight of evidence” approach to gauge the quality of reported data and to compare relevance of results from different studies.

They studied Bayer’s clothianidin and imidacloprid and Syngenta’s thiamethoxam, all used in seed treatments for various field crops.

The original papers, Solomon said, varied in quality and “scientific rigour,” but their results generally showed no adverse effects of pesticides on honeybee hives.

For all three products, the “overall weight of evidence,” based on the studies analyzed, indicated “no adverse effects on colony viability or survival of the colony,” the team wrote in the Journal.

“At least for honeybees, these products are not a major concern,” Solomon said in a university release Tuesday — though he granted the three pesticides can kill individual honeybees, and could also posethreats to other pollinators.

They distinguish between studies showing harm to individual bees and studies that look at impacts on entire colonies.

“What regulations try to protect is the colony — the reproductive unit.” they said.



The Guelph researchers also stressed the importance of “good agricultural practices” in farmers’ neonic use, including making sure the treated seeds are coated and planted properly to avoid airborne contamination of bees during seeding.




Sadly, this is unlikely to change the political decisions at Queen's Park to sharply curb the use of neonics and therefore increase the risks of reduced yields, revenues and farmer profits.