Policy clouds Manitoba's fight against mosquitoes

Winnipeggers are wondering which is worse: the stings from hordes of mosquitoes or the city's implementation of its ineffective spraying policy.

Eliminating the bloodsuckers in Winnipeg is at the mercy of a control policy that is dependent on residents and private businesses allowing their property to be sprayed. The same policy exists in Grand Forks.

Winnipeg boasts Canada's largest municipal mosquito control program, monitoring 40 to 50 species in a 185-square-mile city of 750,000 people, compared with 19.2 square miles and 55,600 in Grand Forks, plus five square miles and 7,800 people in East Grand Forks.

Ground spraying in Grand Forks and East Grand Forks is triggered by an average mosquito trap count of 100 or the presence of West Nile virus-carrying Culex tarsalis mosquitoes in the city traps. Spraying was scheduled Thursday night when the morning trap count was 38. The cities have sprayed seven times since May.

Winnipeg's mosquito trap counts have averaged close to 400, according to CBC News. Some have gone as high as 1,000, the worst outbreak since 2005. How bad is it up north? Residents have raided store shelves of repellents, are hesitant to go outside during the day and make sure their windows are closed at night.

The city did not break out its fogging guns and 18 spraying trucks until June 19.

Distance and time

Two initiatives to untangle the mosquito-spraying red tape were delivered to Winnipeg City Hall this week by two of its powerful politicians.

Councilman Gord Steeves wants to re-examine what he calls an "extremely volatile, divisive and misunderstood" buffer-zone policy. Homeowners can register their property on a do-not-spray list -- the city leaves a 328-foot buffer around a registered property, a zone that can cover 32 to 40 houses in a neighborhood.

Grand Forks residents also can apply for a buffer zone.

"There's nobody on the list," said Todd Hanson, mosquito control supervisor for Grand Forks Public Health. "If someone doesn't want their property sprayed, we honor that until Culex tarsalis are present, then it's not an option."

Taz Stuart, Winnipeg's mosquito control officer, said the same rule applies to his city with the addition that a scientific committee determines a public health risk. Stuart said the presence of buffer zones makes it difficult to obtain permits to use aerial spraying to attack the swarms.

Steeves said buffer zones are excessive.

"My sense is we should be able to apply a chemical in an envelope that could suitably protect somebody in a much smaller bubble than that," Steeves told the Winnipeg Free Press.

Sam Katz, Winnipeg mayor, wants to speed up Winnipeg's entire fogging policy. Right now, before fogging trucks can start spraying, the city must have average trap counts above 25 insects for three days straight, one quadrant of the city must have a trap count of more than 100 mosquitoes and 48 hours notice must be given to the public.

"By that time, you know what the mosquito trap counts are? In the hundreds and thousands," Katz told the Winnipeg Free Press.

Chemical concerns

Fogging may be ordered by the province when Manitoba Health determines the threat of West Nile virus demands the use of pesticides, as it did in 2005. Winnipeg is the only major city in Canada that uses the insecticide Malathion to control mosquitoes, but there's pressure to move toward more environmentally friendly products.

Before the spread of West Nile virus, Malathion was used on a regular basis during summer months to kill nuisance mosquitoes, but homeowners were allowed to exempt their properties if they chose, creating the buffer zone policy.

Hanson said Malathion was used years ago in both Grand Forks and East Grand Forks. He said it's an effective product but he's discontinued using it for a few reasons.

"It puts mosquitoes into a feeding frenzy before they die," Hanson said. "It's an offensive smell, and it's very corrosive."

The insecticide is said to have a relatively low toxicity to humans, but Hanson said the people most at risk from Malathion are mosquito-control employees.

Review begins

Winnipeg's City Council voted Wednesday night to have administrators review the mosquito control policy and report back in about a month. The review will consider:

- Reducing the size of buffer zones or scrapping them altogether.

- Phasing out Malathion in favor of a safer product called Permethrin, which is used by Grand Forks Public Health. Problem is, Health Canada's Pest Management Regulatory Agency hasn't approved Permethrin for battling the bugs. Another problem: Permethrin is five times more expensive than Malathion.

Stuart, the mosquito control officer, said last weekend's spraying reduced average trap numbers this week in Winnipeg from a high of 144 to a low of 63. The average count Thursday was 100, with very low numbers of Culex tarsalis.

The Winnipeg Free Press and the Winnipeg Sun contributed to this report. Reach Johnson at (701) 780-1262; (800) 477-6572, ext. 262; or send e-mail to jjohnson2@gfherald.com .