Larvicide treatment of roadside catch basins leads regional effort to reduce mosquito populations

The Regional District of Central Okanagan (RDCO) is advancing its mosquito control efforts with a targeted program to treat more than 12,000 roadside catch basins across the region between June 20 and 26, 2026. Crews will apply water-soluble larvicide pouches to prevent mosquitoes from developing to adulthood, reducing nuisance levels and lowering the risk of mosquito-borne illnesses such as West Nile virus.

This work complements the RDCO’s broader annual mosquito surveillance and control program, which focuses on identifying and treating standing water sites where mosquito larvae develop. Since April, crews from Duka Environmental Services Ltd. have monitored more than 200 locations, including ponds, marshes, swamps, seepage areas and temporary water accumulations, applying a biological larvicide that specifically targets mosquito larvae.

Residents also play a critical role in limiting mosquito populations. Even small actions can significantly reduce breeding opportunities around homes.

“Most mosquito larval reproduction occurs in small, often overlooked water sources,” says Curtis Fediuk, Senior Biologist with Duka Environmental Services Ltd. “By regularly removing standing water, residents can prevent mosquitoes from becoming a problem before they emerge.”

Reducing mosquito breeding at home

Standing water is the primary development habitat for mosquitoes, and only a few millimetres are needed for larvae to develop. Residents are encouraged to inspect their properties and take the following steps:

• Empty and drain stagnant water from items such as plant pots, buckets, garbage cans, old tires and pool covers
• Ensure rain barrels are sealed with tightly fitting lids or screened openings
• Replace water frequently in birdbaths, pet dishes and wading pools at least twice weekly
• Maintain ponds through aeration or by introducing fish that feed on mosquito larvae

Encouraging natural predators, including birds, bats and dragonflies, can further help manage mosquito numbers.

Protecting against mosquito bites

In addition to reducing breeding sites, residents can take measures to limit exposure to mosquitoes:

• Use approved insect repellents
• Wear light-coloured, loose-fitting clothing
• Avoid densely treed or shaded areas during peak activity periods at dawn and dusk
• Inspect and repair window and door screens to prevent mosquitoes from entering homes

Regional program delivery

The RDCO mosquito control program is delivered across multiple participating areas, including the City of Kelowna, District of Lake Country, District of Peachland, Westbank First Nation, the Sunset Ranch community in the Central Okanagan East Electoral Area and a portion of West Kelowna Estates.

Field crews use a range of vehicles including pickup trucks, scooters and e-bikes to access treatment sites. Staff will be clearly identifiable, wearing high-visibility safety vests, and all vehicles and equipment will display mosquito control signage. Residents are asked to provide crews with additional space, particularly along roadside curbs and bike lanes.

Residents in participating areas can report mosquito concerns online at rdco.com/mosquitoes or by contacting Duka Environmental at 1-800-681-3472.