Mosquito-control changes urged

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This article was published 14/07/2010 (5903 days ago), so information in it may no longer be current.

The City of Winnipeg wants provincial permission to reduce the size of pesticide-free buffer zones placed around homes during mosquito-fogging season — but it’s going to be up to the Selinger government to determine how big those zones should be.

Less than three weeks after city council ordered up an election-year review of Winnipeg’s mosquito-control policy, city entomologist Taz Stuart completed a report that recommends a more aggressive nuisance mosquito program that takes less time to get started and cover the entire city.

Stuart also recommends replacing the chemical larvicide Dursban with biological alternatives by 2012 and asking the Manitoba government for the money to fund the move.

His key recommendation involves reducing the size of buffer zones from the current 100-metre radius — and setting up some means to ensure nobody abuses the buffer-zone policy by registering multiple properties.

Right now, 1,572 registered buffer zones in Winnipeg — which represent less than one per cent of the city’s residential properties — prevent malathion fogging from taking place in 4.8 per cent of Winnipeg’s 21,800 hectares of "treatable properties," Stuart writes.

"It is difficult to predict how this area affects mosquito population control, because of the numerous variables involved," he writes, citing housing density, wind direction, vegetation and relative humidity as other factors.

Nevertheless, Stuart recommends reducing the size of the buffer zones, which have been in place in some capacity since 1969, when the city switched from the notorious pesticide DDT to malathion as an adult-mosquito fogging agent.

No target size for the zone is listed, leaving it up to the province — which licenses the insect control branch’s use of pesticides — to make the politically contentious decision.

"I was kind of hoping the report would come back and be a little stronger than that," said St. Vital Coun. Gord Steeves, who pressed for a buffer-zone review at the same time Winnipeg Mayor Sam Katz pushed for a broader mosquito-control policy update.

Steeves said he is overall very pleased with the report, which calls for buffer-zone registrants to present some proof of identity — either in person, via registered mail or through the use of electronic verification.

"No other issue seems to make people more emotional," Steeves said. "Trap counts seem to spike overnight. Then buffer zones kick in and what happens is everyone, on all sides of the issue, winds up criticizing the policy."

The report calls for nuisance-mosquito fogging to commence more quickly by easing up one precondition for fogging — city-wide average trap counts would now only need to be above 25 for two days, instead of three — and reducing the notification time to begin fogging to 24 hours from 48.

The time it takes to fog the entire city could be reduced to two or three days from the current four or five with the help of an additional $930,000 in annual funding. Stuart writes that fogging all of Winnipeg in one day, as Grand Forks, N.D. does, is not possible, given the size of Manitoba’s capital.

Sitting on a flood plain, Winnipeg is the only major city in Canada to fog for nuisance mosquitoes, he adds. His report makes no mention of eliminating malathion as a fogging agent, presumably because no alternative is licensed for use in Canada.

The city should also speed up the rate it moves toward using only biological larvicides, by spending $3.7 million in 2011 and another $1.7 million in 2012 — with the financial help of the province, according to the report. More aggressive larviciding should also reduce the need to fog for adult pests, Stuart writes.

Reducing the notification times, buffer zones and doing nothing to phase out malathion does not sit well with Josh Brandon of non-profit environmental organization Resource Conservation Manitoba. He said people with chemical sensitivities and respiratory issues need more time to get out of the city before fogging commences.

"We should be putting more research into insect control rather than the more visual aspect of fogging," he said. "I think the government is jumping just a little too quickly to the fogging aspect, rather than the control aspect."

 

— With files from Britt Harvey

bartley.kives@freepress.mb.ca

Revamping the policy

 

City entomologist Taz Stuart’s recommendations for a new mosquito-control policy:

Lead-up time to fogging: Should be reduced from three to two consecutive days with average trap counts above 25 adult mosquitoes.

Public notification before fogging: Should be reduced to 24 hours, from the current 48.

Pesticide-free buffer zones: Size should be reduced from the current 100 metres. Abuse of buffer zones should be reduced by requiring in-person registration with valid identification, using registered mail or using information technology to eliminate multiple registrations.

Increased fogging: Spend an additional $930,000 a year to reduce the time it takes to fog the entire city to two or three days, from the current four or five days.

Larviciding: Bump up elimination of the chemical larvicide Dursban by two years by moving to purely biological treatment of mosquito larvae by 2012. The cost would be $3.4 million in 2011 and an additional $1.7 million in 2012.

Provincial permission: Ask the Manitoba government to approve all of the above — and pick up the financial tab.

Malathion: The report says nothing about the controversial chemical, as no other fogging agent is approved for use.

— Kives