Why are wasps so annoying right now? Understanding the late summer surge

Towards the end of summer, wasp populations typically reach their peak as colonies expand in size and the need for food intensifies in preparation for the upcoming winter season.

As the final days of summer approach in Canada, many people are eager to savour the remaining warm weather and make the most of outdoor activities, however, there’s a persistent threat that can disrupt these plans — the pesky wasp.

Toward the end of summer, wasp populations typically reach their peak as colonies expand in size and the need for food intensifies in preparation for the upcoming winter season.

As the population of wasps grows, so does the potential to get stung. And unlike honeybees, wasps can deliver multiple stings because they don’t leave their stingers behind, explained David Beresford, associate professor in the biology department at Trent University in Oshawa, Ont.

“The wasps, they can tell it’s getting cold, and they need a place to spend the winter,” Beresford said. “So they’re looking for little holes in our shingles, in our eaves, in our decks or our garages, any place they can go to get cover. And so as they’re doing that, it looks like they’re just coming right at us while we step outside.”

Normally wasps are out and about hunting and feeding their larvae and “not paying attention to us,” Beresford said, so there is an “appearance that suddenly the wasps are coming out right where we live.”

Wasps aren’t just searching for a cozy spot for winter hibernation; they also have a keen interest in our meals, be it sizzling meat on the barbecue, a glass of wine or a plate of fruit. This often leads to a flurry of their presence during outdoor gatherings.

By the time the summer wraps up, wasps have had the entire year to build up their populations, explained Rob Currie, a professor of entomology at the University of Manitoba.

“What happens is each year a colony will start off from a single queen and that single queen will go out and forage,” he said. “She’ll collect some bugs and things to feed to larvae and some nectar and build the nest to the point where it expands gradually through the summer. So as the summer progresses, the size of the nest is becoming larger and larger and larger.”