More mosquitoes? Why Canadians could see an uptick this summer and beyond – National

Do you have more mosquitos this summer? You’re not alone.

Canada is teeming with nuisance insects as parts of the country are seeing higher than usual numbers due to the humid, hot weather, raising concerns about related diseases, most notably West Nile virus in humans.

“It certainly seems… anecdotal that it’s a big year for mosquitoes,” said Manisha Kulkarni, a medical entomologist and associate professor at the University of Ottawa.

“We’ve had a warm, wet spring which seems to aid in the spread of mosquitoes early in the season and with the humidity we have and high temperatures likely to continue into the summer months.”

Warmer weather amid climate change means Canada could expect longer mosquito seasons, typically lasting from May to October each year, experts say.

And when mosquitoes are active for a larger part of the year, it poses a “greater risk” to people, wildlife and animals susceptible to mosquito-borne diseases, Kulkarni said.

“With climate change, the models and forecasts assume that these mosquito populations will spread further and further north into more and more regions.”

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Metro Vancouver is buzzing with mosquito complaints

A study published in the Lancet last year predicted that rising global mean temperature will increase the climatic propensity of malaria and dengue, particularly in already endemic areas in the African region, Americas and eastern Mediterranean.

The population at risk for both diseases could increase by as much as 4.7 billion people by 2070, the 2021 study showed.

Globalization and the climate crisis have also led to new vectors entering Canada that didn’t exist before, said Rosalind Murray, an assistant professor in the Department of Biology at the University of Toronto, Mississauga.

“We’re starting to see new species of mosquitoes, and with those species, we might see new diseases that they can transmit, or an influx of different types of diseases,” she said.

National mosquito surveillance data for this year is not currently available, according to the Public Health Agency of Canada (PHAC).

With data still being collected at the local and provincial levels, Murray said it’s too early to know in the middle of the season whether there will be more mosquitoes in Canada this year. However, some signs point to increased activity.

In British Columbia, observers on the lower mainland say heavier and more persistent rains have led to more mosquitoes this summer.

More rain in the city of Regina has caused the mosquito population to nearly triple the historical average in the last month. That number has since fallen, according to the city’s latest data.

A peak of activity depends on local conditions and the nature of the species, experts say.

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Mosquitoes carrying the West Nile virus have been found in Manitoba, according to the provincial government

August is a big month for the main carriers of West Nile virus – a mosquito-borne virus that can cause serious illnesses – Kulkarni said.

They tend to breed in stagnant water, like clogged rain gutters, bird baths or flower pots, she said.

Local and provincial jurisdictions monitor mosquito activity by tracking West Nile virus and other mosquito-borne diseases.

Last week, the province of Manitoba confirmed its first human case this summer of West Nile virus, which is endemic in parts of Canada.

Locally acquired cases occur in Alberta, Saskatchewan, Manitoba, Ontario and Quebec.

“Once we see these positive pools for the number of mosquitoes that test positive for West Nile virus and are collected from different locations, we will start to conduct active mosquito control in areas as well,” Kulkarni said.

In 2021, PHAC 35 human cases were reported across Canada. In 2020 there were 163.

Some people are more attractive targets for mosquitoes than others, experts say.

In addition to individual characteristics such as bacterial colonies on your skin and the amount of carbon dioxide we produce, behaviors also make a difference.

“The more we breathe, are active, wave around, the more mosquitoes we actually attract,” Kulkarni said.

Wearing darker clothing attracts some species of insects, including mosquitoes, so light-colored and thicker clothing is recommended.

Drinking alcohol also makes you an attractive target, said Victor Shegelski, an associate professor of life sciences at the University of Alberta.

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Put mosquito myths to the test

While an encounter with the pesky insects is inevitable, there are steps people can take to protect themselves, including using repellents.

Murray advised using repellents containing DEET.

“You’re most active at dusk and dawn, so this is the most important time to make sure you’re covered,” she said.

Both Murray and Kulkarni warned against having standing water around your property, which is a breeding ground for mosquitoes.

“They can reproduce in really small amounts of water, so if something has been left out for more than a few days, you want to make sure it’s been drained,” Kulkarni said.