The wacky weather has produced perfect conditions for an aphid explosion and Calgarians are being inundated by the little pests.

The aphid population has exploded, driving innocent picnickers, joggers and outdoors enthusiasts indoors.

Local tree specialist Craig Renney says the number of aphids has doubled since last year and their numbers have grown exponentially in the last couple of weeks.

Renney says they're late coming out this year because of the late start to the summer.

"It's just like mosquitoes right? I mean basically you get the damp and then all of a sudden you get that heat. And the heat with the damp and the heat with the damp, brings a lot of vegetation and the more vegetation the more aphids because that's what the aphids need to feed," said Renney.

Renney says the aphids are also affecting a wider variety of trees and plants this year than in the past and that fungus has been an issue as well.