Mosquito population plunges by up to 75% in Calgary, expert estimates

If you think you are seeing fewer mosquitoes this summer, it's not your imagination. The skeeter population has dropped by up to 75 per cent this year in Calgary and area, an entomologist estimates.

Despite wet weather in July, Calgary's dry winter and spring kept populations down

The number of mosquitoes in Calgary this year is down sharply because of the dry winter and spring, a U of C entomologist says. (CDC Global/Flickr)

If you think you are seeing fewer mosquitoes this summer, it's not your imagination.

University of Calgary entomologist John Swann estimates the mosquito numbers have plunged to only about 25 to 50 per cent of what he would normally see, owing to a dry winter followed by a dry spring. 

"Yes, we've had a lot of rain now, and we're almost 200 per cent the normal for July, but it's almost too late to start really developing those summer mosquitoes," he said. 

"So we might start to catch up to more normal levels, but you won't, you know, see mosquito-geddon out there, I suspect, this summer."

Another factor is that the city has twice used a technique to control mosquito outbreaks.

Jim Watts, an integrated pest management technician, says the city recently dropped an insecticide to kill larvae in pools of standing water left from last week's rain.

He says the strategy was used successfully in May and he expects similar results this time.

"With these temperatures we would have adults from these rains at least by the weekend," he said.

"But it looks like another very effective result from our aerial program."

Watts said the weekly trap count in mid-July would normally be a couple of thousand mosquitoes per trap. Last week, his team counted just 111 mosquitoes in the traps.