COVID-19 may have indirectly boosted mosquito numbers in one Fraser Valley neighbourhood. (Pixabay photo/File photo)

COVID-19 may have contributed to bad Fraser Valley mosquito season

Restrictions on helicopter occupancy may have resulted in less effective pesticide treatments

The COVID-19 pandemic may have played a role in making 2020 a particularly bad year for mosquitoes.

Weather and river conditions were the chief drivers of one of the worst mosquito seasons in recent memory. But occupancy limits in the helicopters that apply apply pesticides to mosquito breeding grounds may also have left some of the blood-sucking pests’ prime habitats under-treated.

A report to the Fraser Valley Regional District, notes that the season was shaping up fairly normally through June 5, when the river initially peaked. But instead of slowly receding over the summer, river levels dipped, then started to rise again, peaking once again on June 30 – above the level of the first peak.

Every year, the FVRD hires a private company to apply larvae treatments to mosquito breeding grounds along the river. In 2019, those wrapped up on June 21. But in 2020, the persistently high water required mosquitoes kept hatching through August. The last treatments were applied on August 17.

RELATED: Mosquito sites being monitored and mapped across the Fraser Valley

In all, just shy of 20 tonnes of one pesticide agent were used by Morrow BioScience, the company tasked with treating and eliminating mosquitoes. (The pesticides aren’t sprayed; rather a larvicide that the FVRD says is environmentally friendly is applied in granular or liquid form. The mosquito larvae ingest a toxic protein that kills them.) Even in 2012, another bad mosquito year, 14,489 kg were applied – 30 per cent less than this year’s total.

Each application of the pesticide kills about 90 per cent of larvae. But there were just too many mosquitoes in 2020.

“Based on the extremely high larvae abundance in 2020,” the FVRD report says, “despite the intensive treatment effort, the remaining 5-15% of surviving larvae that hatched into adults were enough to cause unfortunate annoyance in many lowland areas near the Fraser River.”

Last year, only four people called a mosquito hotline on which people can report the pests. This year, 130 calls were received. Of those, the vast majority – 99 – were from Chilliwack residents. And most of those were from Fairfield Island, the residential area of Chilliwack closest to the Fraser River and surrounded by sloughs.

The mosquitoes on Fairfield Island could be an indirect result of the COVID-19 pandemic.

Helicopter and boat crews were limited due to COVID-19 safety protocols. And while the report by FVRD staff said “these limitations are not believed to have significantly impacted the treatment efficacy,” a separate Morrow BioScience report suggested some potential effect.

“It is possible that sites were not treated as thoroughly as usual,” Morrow BioScience report said. “The high number of concern calls associated with Fairfield Island [in Chilliwack] indicate the possibility that sites on that island may have been over-looked.”

Do you have something to add to this story, or something else we should report on? Email:
tolsen@abbynews.com


Contact the reporter on Twitter at
@ty_olsen

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Just one of more than 200 cats and kittens who were adopted through the Chilliwack Animal Safe Haven in 2020, despite the pandemic. (Philip Tingey/ Safe Haven)
More than 200 cats and kittens adopted through Chilliwack Animal Safe Haven in 2020

Successful year took place despite of, or perhaps because of, the COVID-19 pandemic

Kent Search and Rescue sent down three rescuers
UPDATE: Two people involved in ATV rollover 100 feet down ravine in Harrison, at least one injured

Incident happened shortly before 5 p.m. on Harrison East Forest Service Road

An amethyst rock was stolen from Swinstones Granite Shop’s showroom in Chilliwack on Yale Rd. West, and they are hoping it will be spotted and returned. They discovered their window smashed and the purple rock stolen on the morning of Jan. 17, 2020. Here a portion of it is pictured to the right. (Submitted image)
Amethyst stolen from Chilliwack stone shop’s showroom

Window smashed at business where purple rock has been on display for nearly 16 years

Alvin (left) and Theodore, seen here at the Chilliwack SPCA on Thursday, Jan. 14, 2021, are looking for their ‘furever’ home. (Jenna Hauck/ Chilliwack Progress)
VIDEO: Find Me My Furever Home – Theodore and Alvin at the Chilliwack SPCA

Don’t overlook senior pets when wanting to adopt an animal says Chilliwack SPCA branch manager

The City of Chilliwack is looking for proposals to install a piece of public art in this area in front of 46115 Yale Road as seen on Thursday, Jan. 14, 2021. (Jenna Hauck/ Chilliwack Progress)
Artists sought for Five Corners public art project in downtown Chilliwack

Goal of project to increase foot traffic on street, animate Chilliwack’s historic downtown

A scene from “Canada and the Gulf War: In their own words,” a video by The Memory Project, a program of Historica Canada, is shown in this undated illustration. THE CANADIAN PRESS/HO - Historica Canada
New video marks Canada’s contributions to first Gulf War on 30th anniversary

Veterans Affairs Canada says around 4,500 Canadian military personnel served during the war

A 17-year-old snowmobiler used his backcountry survival sense in preparation to spend the night on the mountain near 100 Mile House Saturday, Jan. 16, 2021 after getting lost. (South Cariboo Search and Rescue Facebook photo)
Teen praised for backcountry survival skills after getting lost in B.C.’s Cariboo mountains

“This young man did everything right after things went wrong.”

Conservative Leader Erin O’Toole holds a press conference on Parliament Hill, in Ottawa on December 10, 2020. THE CANADIAN PRESS/Sean Kilpatrick
No place for ‘far right’ in Conservative Party, Erin O’Toole says

O’Toole condemned the Capitol attack as ‘horrifying’ and sought to distance himself and the Tories from Trumpism

A passer by walks in High Park, in Toronto, Thursday, Jan. 14, 2021. This workweek will kick off with what’s fabled to be the most depressing day of the year, during one of the darkest eras in recent history. THE CANADIAN PRESS/Chris Young
‘Blue Monday’ getting you down? Exercise may be the cure, say experts

Many jurisdictions are tightening restrictions to curb soaring COVID-19 case counts

Pindie Dhaliwal, one of the organizers for the Surrey Challo protest for Indian farmers. She says organizers were told by Surrey RCMP that the event was not allowed due to COVID-19. Organizers ended up moving the protest to Strawberry Hill at the last minute. (Photo: Lauren Collins)
Indian farmers rally moves as organizers say Surrey RCMP told them they couldn’t gather

Protest originally planned in Cloverdale, moved to Strawberry Hill

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

A health-care worker prepares a dose of the Pfizer-BioNTech COVID-19 vaccine at a UHN COVID-19 vaccine clinic in Toronto on Thursday, January 7, 2021. THE CANADIAN PRESS/Nathan Denette
COVID-19: Provinces work on revised plans as Pfizer-BioNTech shipments to slow down

Anita Anand said she understands and shares Canadians’ concerns about the drug company’s decision

Tourists take photographs outside the British Columbia Legislature in Victoria, B.C., on Friday August 26, 2011. A coalition of British Columbia tourism industry groups is urging the provincial government to not pursue plans to ban domestic travel to fight the spread of COVID-19. THE CANADIAN PRESS/Darryl Dyck
B.C. travel ban will harm struggling tourism sector, says industry coalition

B.C. government would have to show evidence a travel ban is necessary

(Phil McLachlan - Capital News)
‘Targeted’ shooting in Coquitlam leaves woman in hospital

The woman suffered non-life threatening injuries in what police believe to be a targeted shooting Saturday morning

Most Read