This summer, many prairie cities experienced a surge in mosquito populations, resulting in stores in Manitoba, Saskatchewan, and Alberta running out of bug spray due to high demand. Data from the City of Edmonton revealed a significant increase in mosquito numbers, with July seeing 15 times more mosquitoes compared to the previous year. While not record-breaking, these numbers marked a noticeable shift from the past two summers, intensifying public perception, according to Peter Daly, a biological sciences technologist in Edmonton.
Similarly, Saskatoon and Winnipeg reported higher mosquito counts in July compared to the previous year. In southern Ontario, the excessive rainfall this summer contributed to a mosquito boom, leading to prolonged mosquito activity causing itchy red welts even into September. Fiona Hunter, a professor at Brock University specializing in entomology, highlighted the prevalence of the Ochlerotatus trivittatus species in southern Ontario this year. This floodwater mosquito thrives in water-filled areas, benefiting from the abundant rainfall that created optimal breeding grounds this season.
Experts noted that the Ochlerotatus trivittatus species is known for its persistent biting behavior, potentially explaining the increased encounters with this species. The heavy rainfall across southern and southwestern Ontario could have triggered the hatching of dormant mosquito eggs, contributing to the current mosquito population surge. As temperatures drop, mosquito activity is expected to decrease significantly, with the insects struggling in extreme heat and perishing in cold conditions.
In Alberta, a recent cold spell led to a decline in mosquito populations following a particularly active season earlier in the summer. While Edmonton has observed a reduction in the dominant local mosquito species, Aedes vexans, warm fall weather has delayed a substantial drop in their numbers compared to previous years. Entomology experts anticipate a potential resurgence of mosquitoes as temperatures rise again, but the populations are unlikely to reach the levels experienced in central Canada.