'Their metabolism is ramped up': Insect populations surge amid hot start to summer

If you’ve noticed an increase in ant nests, caterpillars, and yellow jackets buzzing around, the recent heatwave is partially to blame.

Mike Jenkins, pest management coordinator for the city of Edmonton, said because insects are cold blooded, their metabolism is affected by the ambient temperature.

“Higher temperatures tend to ramp up the activity of most insects,” he said.

Jenkins explained that when it’s cold, their metabolism slows down their life cycle and all of their life processes. Whereas when it’s warm, everything speeds up.

“They’re laying eggs sooner then they would normally, so their population builds up much more quickly.”

Which is why in tropical regions there’s lots of insect activity. In warm climates, bugs have more time to be active throughout the day and night, Jenkins said. In contrast, they become more dormant when it's cold.

“They are either hiding in our houses, or they have a wintering stage that allows them to hibernate in some way,” he said.

According to Jenkins, ants and yellowjackets are able to exploit the warm weather by foraging for more food and bringing it back to the nests. He said the queens tend to lay more eggs and the larva develop faster.

“As long as they can get moisture and the food to feed their young, their nests will just keep growing, and growing, and growing.”


However, it’s a different story for mosquitoes. The blood suckers tend to thrive in hot and humid conditions but since there was no precipitation, their lifecycle was cut short.

“Hot temperatures and dry during the day, those mosquitoes don’t last very long,” Jenkins explained.

“They can only live for a few days. Their metabolism is ramped up but it also speeds up their overall life cycle and they drop out of the system a lot faster.”

The noticeable increase of wasps may make some people uneasy, but Jenkins said they can be a beneficial predator to have around as long as our territory doesn’t overlap with theirs.

Yellowjackets tend to find protein by feeding on other insects like flies and caterpillars, so they’re a good for “natural pest control,” Jenkins explained.

Yellowjackets become less tolerant as the summer winds down: their nests are at their largest and their food supply begins to diminish.

“The older workers are on guard duty, and they’re really cranky, and just want to sting something,” Jenkins laughed.

“That’s when they’re less welcome.”


Ants, much like wasps, eat other insects and can be a benefit to gardens. Although, if they move to nesting on lawns, that’s when they can become a pest problem.

“Generally when pest conditions occur, it’s because something has become unbalanced,” Jenkins told CTV News Edmonton.

“In some cases where we have a huge pest outbreak, and it’s already in outbreak situations that’s when we have to intervene and actually have a chemical treatment or something along those lines.”

Jenkins said if the heat continues over the next few months we could see a larger build up of nests and hives around the province.

“This being Alberta, who knows what we could get next week,” Jenkins laughed. “We could have snow.”