Winnipeg to use malathion for mosquito fogging again this year

The City of Winnipeg will use malathion again if it has to fog for mosquitoes this summer, but officials say they still plan to bring in an alternative to the much-debated chemical.

The insect control branch said Tuesday that it has about 4,550 litres of malathion remaining in its inventory enough to fog the whole city 2times.

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Ken Nawolsky, the city's superintendent of insect control, said crews will still focus on killing mosquito larvae in water using a biological larvicide.

"However, if an adult mosquito control program is required, based on the history of the last 10 years, there is minimal risk of using the remaining stocks of malathion in 2016," he said in a news release.

Last year, Nawolsky said the city will stop buying malathion and move toward using a new product called DeltaGard, which is considered to be a more environmentally friendly but more expensive alternative.

The move came after the city's lawyers advised against signing an indemnification clause, imposed by the manufacturer of malathion, that would release the company from any liability for perceived or actual damage from the product.

On Tuesday, Nawolsky said the city still intends to use DeltaGard if it's approved for use in Canada. It is approved in the United States but not in Canada, but the city says it could be approved as early as in 2017.

"Our goal is to transition over to a new product as soon as possible," Nawolsky said.

The city says it conducted research trials of DeltaGard in August 2015 and found that it is effective. The results were sent to Health Canada's Pest Management Regulatory Agency last fall.

The use of malathion to control Winnipeg's mosquito problem has long been debated, with some residents in favour of foggingto keep their summers bug-free and others opposed to having the chemical sprayed near their homes.

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The International Agency for Research on Cancer (IARC), a specialized agency of the World Health Organization, classified malathion as "probably carcinogenic to humans" last year.

Meanwhile, the city is warning people to expect a "significant amount" of forest tent caterpillars causing "significant leaf damage" in May and June.

Crews will be out applying Btk, a biological spray, once leaves start to emerge, according to the city.