Why you’re seeing more wasps in Calgary this spring (and how to deal with them)

If you’ve noticed more wasps seem to be buzzing around Calgary this spring, a retired provincial entomologist says you’re probably right.

A dry, warm, early spring — like the one Alberta is having now — makes wasp activity more likely to appear.

“It’s been warm for quite a while, so the wasps have had time to build populations,” Mike Dolinski told the Calgary Eyeopener on Thursday.

“[And] if we had really good success in mating last fall, and we had good success during the winter where the queens are hiding — all of a sudden, you have this big number of new worker wasps that are out foraging to support building their colony.”

Cold-blooded predator bears

Wasps, according to Dolinski, are cold-blooded predators. Literally.

Like most insects, wasps are unable to generate their own body heat, and become less active when it gets cool.

Typically, they live under the ground in holes or burrows. If you do have a pesky issue like a wasp’s nest, the best time to try to handle it is when the weather is colder and they are more docile — but without being too bold, Dolinski warned.

When it comes to favourite foods, Dolinski likened wasps to bears because they are omnivores, hungry for both meat and fruit. Insects are definitely on the menu.

“They are predators. They eat mosquitoes, they eat aphids, they eat a lot of other small larva, for example, in trees,” Dolinski said.

“So they play a really critical role, just like ants and other … animals to dispose of wastes around us. And they also pollinate fruits and plants. They’re great.”

What to do (and not to) around wasps

Though they seem less-than-great when they’re dive-bombing you at a backyard barbecue, these tiny bears of the sky are also saving you from mosquitos and helping your garden grow.

So, with stingers in mind, how to we go about keeping things civil with them?

First of all, stop running around when they hover near you, Dolinski said, because they’re going to call their pals to come and attack you.

“As soon as food comes out, they can pick that up and they’re coming to eat it. And if you watch them, they’ll come on your plate and start chewing on things,” Dolinski said.

“A lot of people get in trouble … [because] they try to swat them and dispatch them. And what that does is, it allows the wasp or the hornet to produce an alarm pheromone, and as a consequence, you can suddenly have more wasps in and around you.”

If one does manage to sting you, ice it.

Another word of advice: Watch that pop can.

“They will go in there, and it’s really dangerous if you swallow a wasp, and it stings you on the way down your throat, because then you can get quite a response there,” he said.

“An anaphylactic reaction is really critical if you get it close to your throat or your mouth in terms of the immediate response that occurs in the swelling.”


With files from the Calgary Eyeopener.

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