Bees exposed to real-world levels of a group of pesticides known as neonicotinoids die sooner than those that are not exposed, researchers from Toronto’s York University have found.
In a study published today in the journal Science, the researchers found that bees exposed to levels typically found in corn fields had their lives shorted by almost 25 per cent.
“We found higher worker mortality, deficits in learning and memory, differences in queen and reproductive biology,” co-author Amro Zayed told CBC News. “All of these have been found in other experiments by other researchers. So we’re validating all of these findings.”
The findings in the latest study came as “absolutely zero surprise at all” to Tibor Szabo, a beekeeper in southwestern Ontario.
Szabo, a third-generation beekeeper, has lost so many bees over the past few years that he’s cut his hive numbers in half since 2011. In 2014, he lost 1,165 hives, each containing about 1,000 bees. And the declines just keep on coming. He blames neonics.
“I keep a lot less bees because of the poisoning,” he told CBC News. “I don’t have bees in many of my yards that were good for decades.”
To determine the levels of neonics taken in by the bees, the researchers from York studied 55 hives from 11 apiaries after they placed them in sites across Ontario and Quebec. Five apiaries were near fields planted with corn that was treated with neonics and six away from known treated corn.
They tested pollen collected by the bees for more than 200 agricultural chemicals, known as agrochemicals, and found 26 throughout all the hives.
Over the past decade, beekeepers have noticed declining populations in their colonies. While a common pest known as the varroa mite, along with other factors such as harsh winters, were considered to be contributing to their rapidly declining rates, many apiarists in Ontario, Quebec and parts of Europe noticed another similarity: their bees were living near corn or canola fields.
Today, most corn seed is treated with neonics in order to defend it from pests in the field. But many beekeepers say that it doesn’t have to be applied as a preventative measure; it should be used on an only-as-needed basis.
Some of the arguments…