New research indicates that varroa mites and chronic bee paralysis virus are bigger bee killers than most have believed.
The research spanned a five-year period during which the two foes of bees took an increasing toll.
Dennis vanEngelsdorp, an assistant professor of entomology at the University of Maryland and co-author of the report, says varroa mites are a much bigger threat and “moreover, varroa’s ability to spread viruses presents a more dire situation than we suspected.”
Another disturbing discovery is that the chronic bee paralysis virus (CBPV) that can kill bees within days has skyrocketed.
When it was first detected in 2010, fewer than one per cent of bee samples tested positive.
Now, just four years later, that number has nearly doubled each year and currently sits at 16 per cent.
The researchers plan on also studying the effects of pesticides on bees.
Studies have found that neonicotinoid seed treatments are threatening bees around the world.
“Our next step is to provide a similar baseline assessment for the effects of pesticides,” vanEngelsdorp said.
“We have multiple years of data and as soon as we’ve finished the analyses, we’ll be ready to tell that part of the story as well.”
Grain Farmers of Ontario has been trying to persuade the Ontario government to tone down its restrictions on neonicitinoids until this type of research is completed.