This summer, some prairie cities experienced a surge in mosquito populations, leading to a shortage of bug spray in stores across Manitoba, Saskatchewan, and Alberta. Data from the City of Edmonton revealed a significant increase in mosquito numbers, 15 times higher in July compared to the previous year.
Peter Daly, a biological sciences technologist at the City of Edmonton, noted that while not record-breaking, the spike in mosquito numbers this summer starkly contrasted with the past two seasons, influencing public perception. Saskatoon and Winnipeg also reported elevated mosquito counts in July compared to the previous year.
In southern Ontario, the excessive rainfall witnessed this summer has been attributed to the mosquito boom continuing into September. Fiona Hunter, a professor at Brock University specializing in entomology, highlighted the prevalence of the Ochlerotatus trivittatus species this year. These floodwater mosquitoes thrive in water-filled low-lying areas, benefiting from the abundant rainfall seen in southern Ontario.
The persistent biting nature of Ochlerotatus trivittatus has increased human-mosquito interactions this year, contributing to the perception of a severe mosquito season. Additionally, the heavy downpours in southern and southwestern Ontario may have triggered the hatching of dormant mosquito eggs, exacerbating the issue.
However, as temperatures drop, mosquito populations are expected to decline. Experts anticipate that colder overnight temperatures will lead to the demise of mosquitoes, as they struggle in extreme heat and perish in cold conditions. Alberta, following a recent cold spell, has already witnessed a reduction in mosquito numbers.
While Edmonton and Calgary faced a challenging mosquito season earlier due to early rainfall, the populations have dwindled with the onset of colder weather. Despite a warm fall in Edmonton, mosquito numbers for the dominant local species, Aedes vexans, have started to decrease. As temperatures rise again, a resurgence in mosquito activity is predicted, albeit not to the extent experienced in central Canada.
