By Connor Lynch
GUELPH — Research published last month from the University of Guelph says that, properly used, neonicotinoid-treated corn and soybean seeds are not a threat to bee colonies. Until last year, most corn and soybean seeds in Ontario were neonic-treated seeds.
The study results are a sharp distinction from a report in September from the International Union for the Conservation of Nature (IUCN), a Switzerland-based environmental think-tank.
The U of G research was a meta-analysis of 234 papers, 170 of which were unpublished papers submitted by Syngenta and Bayer to regulatory agencies. The other 64 papers analyzed by toxicologist Keith Solomon and adjunct professor Gladys Stephenson were peer-reviewed papers available in the common scientific literature.
Solomon said that he was approached by Bayer and Syngenta about two years ago, and they gave him access to their unpublished reports they’d submitted for his review.
From studying those and the publicly-available, peer reviewed data, Solomon concluded that the weight of evidence suggested that properly-used neonics were not a threat to honeybee colonies. In their review, Solomon and Stephenson examined clothianidin, imidacloprid, and thiamethoxam, the three most commonly used neonics in Ontario.
They used what’s called a weight of evidence analysis. It not only brings together data and conclusions from many different studies, but weights the individual studies according to their scientific rigour.
The IUCN report’s vastly different conclusion was likely because Solomon and Stephenson’s analysis focused on honeybee colonies rather than the bees themselves, he said. Solomon said they did not examine studies of the toxicity of neonicotinoids on individual honeybees because they know neonics will kill honeybees if given a high enough dose.
“The real question is: Is this happening in the real world?” said Solomon, implying that the University of Guelph study was more realistic.
In 2015, the Ontario government passed a ban on neonic-treated seeds. The Grain Farmers of Ontario argued that the province was anti-science, listening only to environmentalists.