Winnipeg mosquito population should be low this summer, city says

Manitoba is warming and drying and that means it's only a matter of time before mosquito season is upon us. But by the city's estimates, it looks like Winnipeg may be in store for a mild summer as far as the blood suckers are concerned.

Based on the dry conditions, the city said Friday it predicts Winnipeg's mosquito numbers will be on the low side this year.

Ken Nawolsky, superintendent with the city's Insect Control Branch, said the first mosquitoes of the year hatched last weekend. The good news is the biters that come out in the next few weeks will be a little slow.

"The spring species aren't as aggressive and abundant as the summer, and the summer species typically hatch around when there is a significant rain, about mid-May to the long weekend, when the temperatures start increasing rapidly," said Nawolsky.

Adult mosquito monitoring efforts will start May 1, with first trap count tallies being posted to the city's Insect Control website May 4. Four new traps have been added to newer neighbourhoods in hopes of developing a more complete picture of the city's mosquito population.

Malathion supplies dwindling

The city will continue its adult mosquito nuisance fogging program, despite news last month from a World Health Organization (WHO) agency that said malathion is "probably" cancer-causing.

• Malathion 'probably carcinogenic' to humans, WHO agency concludes

• City of Winnipeg malathion fogging dose low, says doctor

Multiple levels of government and several scientists weighed in following the WHO report, claiming results were based on lab mice and didn't apply to the city's use of the insecticide, which they claim is used appropriately, in small doses and doesn't pose a threat to community health.

But with roughly 4,800 litres of the chemical left, Winnipeg's malathion supply is also running low. Nawolsky said the city is trying to find a new insecticide and get regulatory approval for its use by 2016.

"We are working feverishly with the Pest Management Regulatory Agency and other suppliers to see if we can expedite a process to bring up new products here," said Nawolsky.

Before any fogging happens this year, the city first hopes to silence the buzzers using larvicide. To do this, as in previous years, the city will use four larviciding helicopters to douse standing water ponds throughout the city with a biological agent that kills mosquitoes before they can take to the wing. A team of close to 180 workers will help in the effort, covering 31,000 hectares of water across the city.

The cankerworm and forest tent caterpillar populations are also being monitored currently. Cankerworm populations are expected to be low, but the tent caterpillar population could be in the moderate to high range, the city said. 

Winnipeggers can apply for the city's 90-metre buffer zones by emailing the city at 311@winnipeg.ca, by faxing 311, or in person at 1539 Waverley Street.