Calgary's rainy 'bummer of a summer' causes uptick in flies buzzing around
If you've noticed you're swatting away more flies as of late, you're not alone.
Entomologists say Calgary's unusually rainy summer — plus hailstorms in parts of the city — have caused an increase in housefly, blow fly and fruit fly populations.
"We've had what people are calling the bummer of a summer," said John Swann, an entomologist with ABI Environmental Services, on the season's damp and chillier-than-usual weather.
Swann said that while the moisture has been great for plant growth, more rotting vegetation (such as cut grass) has created the conditions for flies to thrive.
"You look at the lawns around Calgary. I mean, certainly the lawns in Varsity have never looked so good," he said. "We are leaving thatch around, that rotting grass.… There's a great environment for flies to breed in."
A garden in the northwest Calgary community of Thorncliffe that was heavily damaged in a July hailstorm is shown in a file photo. Fallen fruits and vegetables can be a breeding ground for fruitflies. (Submitted by Tara Schneider)
Calgary's summer hailstorms have also played a factor in more fruit flies buzzing around, Swann said, with some areas of the city getting golf ball-sized hail that knocked fruit off trees and destroyed vegetable gardens.
Those fallen fruits and vegetables lying around with their skin cut up have become breeding grounds for the common fruit fly.
"The fruit flies get into them because they think it's nice and damp in here and it's the food we love," he said.
Swann said fly populations will take awhile to decline, but he reminds Calgarians that having more flies around means other animals can thrive.
"If those insects are doing really well, things that feed on those insects, including birds, bats, things like that, will do really well," he said, adding that dragonflies and damselflies also like to feed on houseflies.
(Videoblocks)
But if you're still bugged by flies in your home, Swann suggested people clean up their yards and toss any damaged fruit.
Ken Fry, an entomologist at Olds College, said it's not just flies thriving during the wet weather, but mosquitoes and other insects are also out in higher populations.
"We normally would be drying out in July and August — your lawn gets crunchy and you see the roadsides are browning and things like that. But not this year. Everything is still really vibrantly green right now," Fry said.
"That means there's lots of food for the critters … [and] more and more reproduction and more and more survival and hence a lot more critters."
Come September, Fry said Calgarians could have another bug to reckon with: tiny, green aphids.
Fruit fly. (GettyImages-174766622)
"With this really good plant growth, this really good moisture, I anticipate seeing … a large crop of aphids this fall."
In the last few years, large aphid populations have thrived in Calgary, partly due to humidity, Swann said.
But the fate of those insects this year isn't set in stone just yet.
Swann said that along with moisture, aphids need warm temperatures to thrive, so if Calgary stays dry or temperatures don't increase enough, we may see fewer aphids than years past
Thumbnail courtesy of Videoblocks.
The story was originally written by Rukhsar Ali and published for CBC News.