This summer, some prairie cities in Manitoba, Saskatchewan, and Alberta faced a surge in mosquito populations leading to a shortage of bug spray in stores due to high demand. Data from the City of Edmonton revealed a significant increase in mosquitoes in July compared to the previous year. While not record-breaking, this spike contrasted sharply with the past two summers, potentially amplifying public perception, noted Peter Daly from the City of Edmonton.
Similarly, Saskatoon and Winnipeg also witnessed higher mosquito numbers in July compared to the previous year. In southern Ontario, the excess rainfall experienced this summer likely contributed to the mosquito boom, prolonging their presence into September. Fiona Hunter from Brock University explained that the Ochlerotatus trivittatus species, known as floodwater mosquitoes, thrived in the wet conditions created by the heavy rains in southern Ontario.
According to Hunter, the persistent biting nature of the Ochlerotatus trivittatus species might explain why people encountered them more frequently this year. Moreover, Rosalind Murray from the University of Toronto pointed out that the torrential downpours across southern and southwestern Ontario might have triggered the hatching of dormant mosquito eggs, especially in flood-prone areas like Toronto.
As temperatures drop, mosquitoes are expected to diminish as they are not well-suited to extreme heat or cold. Ken Fry from Olds College in Alberta mentioned that mosquito populations in Edmonton and Calgary declined significantly after a cold snap following a rainy start to the summer. Although Edmonton saw a reduction in the dominant mosquito species, Aedes vexans, the warm fall delayed a steep decline in their numbers compared to previous years. Fry suggested that mosquito activity might increase if temperatures rise above 20°C in the upcoming week but not to the extent experienced in central Canada.
