This summer, many prairie cities experienced a surge in mosquito populations, leading to a shortage of bug spray in stores in Manitoba, Saskatchewan, and Alberta due to high demand. Data from the City of Edmonton revealed a significant increase in mosquito numbers, 15 times higher in July compared to the previous year, according to Peter Daly, a biological sciences technologist at the City of Edmonton.
Saskatoon and Winnipeg also reported elevated mosquito activity in July compared to the previous year. In southern Ontario, the record rainfall experienced this summer is believed to have fueled the mosquito boom, extending their presence well into September. Fiona Hunter, a professor at Brock University specializing in medical and veterinary entomology, noted a rise in the Ochlerotatus trivittatus species in southern Ontario this year. This floodwater mosquito thrives in water-filled low-lying areas, taking advantage of the abundant rainfall in the region.
The persistent rainfall in southern Ontario created ideal breeding grounds for mosquitoes, as standing water in various areas provided ample habitat for the insects. The species’ aggressive biting behavior has led to more frequent human-mosquito encounters this year, contributing to the perception of a particularly severe mosquito season.
Experts suggest that the heavy rainfall triggered the hatching of dormant mosquito eggs across southern and southwestern Ontario, potentially leading to a temporary surge in mosquito populations. However, with the onset of colder temperatures, mosquito activity is expected to diminish. Mosquitoes struggle in extremely hot and dry conditions, and they perish in cold temperatures below 10 degrees Celsius.
Reports from Alberta indicate a decline in mosquito numbers following a cold snap, with expectations of reduced mosquito populations once temperatures drop further. Despite a warm fall in Edmonton, mosquito numbers of the dominant local species, Aedes vexans, have started to decrease. However, a resurgence in mosquito activity may occur as temperatures rise above 20 degrees Celsius in the coming week, albeit at lower levels compared to central Canada’s mosquito situation.