While evidence mounts that neonicotinoid pesticides are contributing to the deaths of honeybees, new research from the University of Guelph suggests there’s little evidence the pesticides are impact bee populations at a colony level.

Researchers found that while three common pesticides produced by Bayer and Sygenta can kill individual honeybees, there is no evidence linking them to the major die-offs seen in honeybee populations in recent years.

“Use of these neonics under good agricultural practices does not present a risk to honeybees at the level of the colony,” emeritus environmental professor Keith Solomon said in a news release.

“Good agricultural practices” include making sure seeds are coated and planted properly, to reduce the possible contamination of bees. Neonicotinoids are typically used by farmers to keep their crops free of pests.

Pesticides studied by the Guelph team include thiamethoxam, which is produced by Syngenta, and the Bayer-made clothianidin and imidacloprid.

The findings were based on 64 published papers and 170 unpublished studies and reports which were commissioned by the manufacturers of the pesticides.

Solomon and adjunct professor Gloria Stephenson found that none of the studies showed that the pesticides have harmed honeybee colonies.

The research has been published in this month’s edition of the Journal of Toxicology and Environmental Health-B.

In September, a group of scientists called on the Canadian government to ban the use of all neonicotinoid pesticides due to their effect on honeybees. A similar ban in France will take effect next year.

With files from The Canadian Press