Ontario beekeepers are crossing their fingers as they worry spring planting might bring a repeat of widespread bee deaths they blame on a group of insecticides with a disputed record.
New federal and provincial guidelines ask farmers to plant corn only under specific, controlled conditions to minimize small particles of insecticide dust escaping from the seed coatings into the bees’ turf.
But the guidelines are voluntary, and even apiarists say farmers are rarely able to wait for perfect planting conditions.
Dan Davidson, president of the Ontario Beekeepers Association, said corn was planted on a field near one of his bee yards last Friday.
On Monday morning, he found many of those bees had died. “There were hundreds in front of some of the hives.”
Last year at this time, bees examined after mass die-offs at Davidson’s Watford-area hives were found to have high levels of neonicotinoids, an insecticide used to coat corn seed.
Canada’s Pest Management Regulatory Agency says between April and June 2012, Southern Ontario had “an unusually high number” of bee losses from a reported 40 beekeepers and more than 200 bee yards.
The die-offs coincided with the timing and location of corn planting: 70% of those dead bees sampled were found to have residues of the same neonicitinoid used to coat crop seed.
The agency recommends farmers avoid planting in dry or windy conditions, upwind of bee yards and improve equipment to reduce pesticide dust.
But that’s not always realistic, said Chris Hiemstra of Clovermead Adventure Farm near Aylmer.
“They’re fighting weather and they just can’t wait for perfect conditions,” said Hiemstra.
Bees found dead at his hive entrances last year tested positive for neonicotinoids, designed to affect the nervous systems of damaging insects. Hiemstra hopes this year’s planting will have minimal impact on his bees. “You just cross your fingers and hope for the best,” he said.
The pesticides have been in use for more than a decade and have been credited for controlling otherwise damaging insects.
Industry advocates have condemned suspicion of the product as junk science.
Even so, the European Union will partly ban three types of neonicotinoids around flowering crops, starting in December, because of concerns about bee-colony collapses. And Ontario government researchers will monitor their effects on bees in several areas of the province this year. They’re also testing better ways to make the insecticide “stick” to the seed.
Davidson is among a growing number of beekeepers who believe the pesticide’s effect may also show up in more subtle but equally alarming ways.
Davidson said sub-lethal doses seem to be affecting bee ability to learn and remember, to navigate back to the hive and longevity and fertility.
“Our queens are not lasting as long and (they’re) just outright dying . . . You lose the queen, you lose the hive,” Davidson said.
About 80% of seed-based crops need pollinators such as bees. Often, apiarists are also cash-crop farmers themselves or rent their bees to farmers.