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‘Perfect storm’ led to bad year for mosquitos near Fraser River

High river levels and lots of rain meant many eggs hatched this year
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It’s been a bad year for mosquitoes in the Fraser Valley. (Black Press Media files)

If you want to become an involuntary blood donor this year, go for a walk near the Fraser River, and the mosquitoes will gladly oblige.

It’s one of the worst summers for mosquitoes in years, and multiple episodes of high water on the river is being blamed, having left behind pools and puddles that are prime breeding ground for the insects.

“The mosquitoes are bad in Fort Langley with the extended high water,” said Cheryl MacIntosh, commodore of the Fort Langley Canoe Club.

Although the club has shut down its group activities due to the coronavirus pandemic, individual members are still paddling about alone or in family groups. But getting into the water isn’t that much fun right now, MacIntosh said.

“Preparing the boat, loading and unloading by the water are the difficult times,” she said. “Once on the water and moving they are not as bad, as long as you keep moving.”

Morrow BioScience is running the nuisance mosquito program for Metro Vancouver again this year.

“It’s not been a particularly good year for mosquitoes,” said Shaun Calver, Morrow’s operations manager.

In fact, a combination of a rather damp July and multiple high-water events on the Fraser River have resulted in what he called a “perfect storm” for mosquitoes.

Each rainfall, and especially the high water levels, created conditions for more mosquito eggs to hatch, and more larvae to become blood-sucking adults.

However, the end is near.

“It is tapering off,” Calver said.

The mosquitoes live several weeks in their adult form, depending on the temperature.

“The hotter the weather, the quicker they die off,” he said.

Morrow BioScience applies bacterial larvicide to water bodies to try to cut down on the numbers of the biting insects, as well as monitoring larva levels and conducting public education on mosquito prevention.

The company is finished with its larvae control efforts for the year, barring another unlikely rise in river levels, Calver said.

Local municipalities and Metro Vancouver have long advocated for people to help control mosquitoes by removing unnecessary standing water on their properties, particularly items like old tires, blocked gutters, bird baths, or buckets that can hold stagnant rainwater.

Mosquitoes are most active between dusk and dawn, and are attracted to dark and intense colours. To avoid them, try to wear light coloured clothing, wear long-sleeved shirts and pants, and tightly-woven materials. Mesh “bug jackets” or “bug hats” may be needed during extreme conditions.

Morrow also recommends using an insect repellent containing DEET.



Matthew Claxton

About the Author: Matthew Claxton

Raised in Langley, as a journalist today I focus on local politics, crime and homelessness.
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