Public Health launches annual mosquito larvicide program

With warmer weather comes the return of mosquito season, and work has begun to reduce mosquito populations in the Wellington-Dufferin-Guelph region. 

Wellington-Dufferin-Guelph (WDG) Public Health announced on May 19 the launch of their annual mosquito larvicide program, which aims to reduce mosquito populations known to carry West Nile virus. The program will run until early October. 

“Mosquitos are more than just a spring and summer time annoyance,” said Dr. Nicola Mercer, Medical Officer of Health and CEO of WDG Public Health. “Some species may carry the West Nile virus which, if transmitted to humans, may cause flu-like symptoms and in rare cases, inflammation of the brain or spial column can occur which may result in permanent disability or death.” 

Through the program, trained technicians apply larvicide by hand in areas of standing water in and around communities in Wellington and Dufferin County helping to reduce or eliminate mosquito populations. 

According to WDG Public Health, in 2021 there was one confirmed human case of the West Nile virus, and two cases in birds identified in the Wellington-Dufferin-Guelph region. 

“By proactively treating areas of standing water on municipal property, we're helping to prevent these areas from becoming sites for mosquitoes to breed,” said Mercer. 

Mosquitoes lay their eggs in standing water so eliminating the breeding areas is the first line of defense. Larvicide is used in potential larvae breeding sites where standing water cannot be eliminated or is more difficult to control.

These areas include roadside ditches, temporary pools, sewage lagoons, storm-water retention ponds, areas of standing water, and municipal catch basins.

Public Health is encouraging property owners to remove standing water anywhere it tends to collect including flower pots, bird baths, wheelbarrows, eaves troughs, rain barrel and tires. 

Public Health said residents can reduce the risk of mosquito bites and potential exposure to West Nile virus by wearing light-coloured pants and long-sleeved shirts, avoiding being outside at dawn and dusk when mosquitoes tend to feed, and using mosquito repellent with DEET or Icaridin for adults and children over 6 months of age.