Are pesticides killing Ontario bees?

Tuesday, February 5, 2013

A preliminary report by a federal agency suggests that pesticides used on corn seeds may have been a factor in bee losses experienced last spring. The leading pesticide manufacturer concerned is not so sure

by MARY BAXTER

For Ontario's beekeepers, 2012 seemed, at its outset, a most promising year. "It was a very early spring, dry conditions," recalls John Van Alten, past president of the Ontario Beekeepers Association and a beekeeper in Carlisle, near Hamilton. "Bees were exceptionally strong compared to the last few years."

Then, around corn planting – mostly in an area bounded by London, Sarnia and north to Goderich and Bruce County – bees began to die.

Many beekeepers who contacted the Ontario Ministry of the Environment reported an abnormally large number of dead bees in front of their hives, says Tom Cowan, a ministry pesticides specialist. "These were the ones that were out foraging because they had the presence of pollen sacs on their legs," he says. Some that were still alive exhibited signs of pesticide poisoning: jerky, twitching movements.

In September, a preliminary report from the federal Pest Management Regulatory Agency (PMRA) concluded that pesticides used on corn seeds "may have contributed" to some of these bee losses.

"The route of the exposure from the seed treatment is still not exactly clear," Cowan says. The ministry has not found any violations of the Pesticides Act, but other factors could be at play. The PMRA, with the support of the provincial environment ministry, has gathered information, such as the kind of crops grown near the affected hives, planting dates and weather as well as the type of planters and seed treatments used. It has not set a date for the release of the final report.

Yet it isn't the first time such treatments have been implicated in bee kills. Earlier in the year, researchers from Purdue University in Indiana and the Connecticut Agricultural Experiment Station had linked corn seed treated with neonicotinoid insecticides to bee deaths in Indiana. Years earlier in France, massive bee die-offs had been attributed to a neonicotinoid insecticide and the country had banned its use in corn seed treatments.

Last spring, the Canadian Honey Council formed a six-member committee to look into the incidents in Ontario. "The fact of the matter is that we know insecticides kill insects," including beneficial ones that happen to be in the wrong place at the wrong time, writes Kevin Nixon, an Alberta beekeeper who is the council's vice-chair, in a Nov. 27 email. The committee is developing recommendations that range from best management practices for all of those involved in the matter and bee poisoning reporting procedures for beekeepers to compensation for the loss of bees and production.

Van Alten estimates 2,000 to 5,000 of the province's 80,000 bee colonies were affected. Damage has ranged from bee colonies dying and not being able to use equipment again to reduced honey production. The provincial organization has tried to open compensation discussions with Bayer CropScience Inc., the only company in Canada that provides clothianidin, a neonicotinoid, for seed treatments. The chemical was found in the majority of the bee samples that tested positive for traces of neonicotinoids (about 70 per cent of 104 samples). "They are willing to talk about improvements that they could suggest but they weren't very amicable to talking about compensation," Van Alten says.

Derrick Rozdeba, Bayer's manager of integrated communications, says it's premature to talk about compensation. "Investigation is still taking place." Paul Thiel, Bayer's vice-president for innovation and public affairs, adds that because the company has not been involved in the site investigations, "we simply can't go down that path at this time."

The two men also question the assertion that bee deaths and neonicotinoid seed treatments are linked. Despite the ban, France's bee population continues to decline, Thiel points out. And Rozdeba notes that in Australia, where the seed treatment is used extensively and varroa mites – a widespread, parasitic bee pest – are absent, there is no pressure on bee health. "This is a very complex issue," he says.

All of those involved are working hard to develop best management practices. These mostly address minimizing the dust that's created during planting. Studies have shown that the talc, used by farmers to reduce the stickiness of pre-treated seeds, can create a light dust during planting that can contain high levels of the insecticide.

Bayer has been working with its industry organizations in both Canada and the United States to make changes in all stages of the seed processing. It is also developing an alternative for talc that will undergo field evaluations in the spring. Looking at ways to adjust downward air discharges from equipment is another priority.

Pierre Petelle, CropLife Canada's vice-president of chemistry, says the industry organization has already held several meetings with the beekeeping community as well as with other agriculture industry representatives. The organization is working with others, such as Grain Farmers of Ontario, to disseminate information to growers about how to minimize dust while handling treated seed during loading and planting. Much of these tips are "things that farmers are used to thinking about when they are applying sprays," he explains. There is also a push to ask PMRA to change labelling requirements on treated seed to help foster greater awareness of the chemical.

Those on all sides of the issue stress the importance of working together to make a better environment for bees. "What we don't want to see happen is that this becomes a beekeeper versus farmer thing," Van Alten says. "We don't want to make farmers afraid to have bees on their property because of liability problems." BF