‘Desperate’ wasps becoming more common throughout Saskatchewan

Dry conditions across Saskatchewan have helped keep the mosquito population down, but when it comes to insects, there has been a trade-off. Wasps are emerging earlier than usual this year, and they’re emerging in a bad mood.

According to University of Saskatchewan assistant professor Sean Prager — whose areas of research include entomology and integrated pest management — drought conditions have brought out wasps earlier than usual.

They’ve also made the insects more aggressive in their search for food.

“We’re supposed to see them this time of year anyway, this is not uncommon,” said Prager. “However, part of the reason we see them at the end of the year, in general, is because the colonies get very large. That’s when they have the most amount of workers in their colonies and the least amount of food, so that’s when they get desperate and start looking for alternative food sources.”

A drought year like the one we’ve had caused plants to flower earlier on average. There are also fewer good sources of food for wasps, so they have to go further afield, Prager explained. When they do, they become increasingly aggressive toward the end of the year.

“We start seeing them in places earlier and in more abundance,” Prager said. “That’s what’s happening, probably. They get more desperate for food, so they’re coming after trash and dead animals and whatever else they can use as a food source.”

Wasps are known to get more aggressive at the end of the season in most years, even when there hasn’t been a lack of rain. Prager has an untested theory behind some of the motivation for wasps getting agitated this time of year.

“The theory is that firstly, they’re going to die anyway,” he said. “Secondly, they’re desperate, so they’re kind of angry.”

As irritable as wasps may seem, Prager said they’re not inherently angry creatures. They feed their young meat, but the adults eat nectar in much the same way a bee does.

“They do need meat for their larvae, they do feed their young meat,” he said. “That’s a part of what we’re seeing and that’s why they’re often going after bits of dead animal and things. When they’re doing that, we don’t encounter them much. That’s why we don’t think about them very often early in the year unless they’re making a nest or something we don’t like.”

Prager added if people want to keep wasps away from their property, commercial wasp traps work very well. He also recommended not leaving things out that wasps like such as pop cans, but said cold weather will swiftly kill them off.