Ladybug boom in Alberta: Why nature’s polka-dotted insect is in abundance this fall

A ladybug is seen perched on a plant. (Pixabay via Pexels)

As people in parts of Alberta enjoy above-average temperatures in the early days of fall, some are noticing an uptick in ladybugs.

Doug Wong, a Calgary resident who has lived in his house for 30 years, says he’s never seen so many.

“There are hundreds and hundreds,” said Wong.

“We see them every year, but not in this quantity. I mean, they’re crawling up your leg. They’re on my cell phone. They’re everywhere.”

Wong’s backyard is covered in a blanket of yellow leaves, and under the foliage, many ladybugs can be found congregating and crawling about.

Nadir Erbilgin, a professor of forest entomology at the University of Alberta, says one reason so many ladybugs are gathering is that they are trying to find a place to sleep for the winter, which happens every year.

“They’re looking for something more than just park crevices—perhaps inside organic layers, leaves, foliage, or soil,” said Erbilgin.

“They spend the winters without eating anything on the bark. Whatever fats they reserve throughout spring and summer, they use up during overwintering.”

Erbilgin says what’s different this year is that there seem to be more ladybugs than usual. He explains that the streak of hot temperatures that hit parts of Alberta in the last weeks of summer and early fall is a contributing factor.

“The hot weather makes the plants stressed,” said Erbilgin.

“When the plants are stressed, they have a lack of water. When they don’t have much water, they reduce their photosynthesis activity. And when they do that, stressed plants attract insects.”

One of those insects is aphids, which ladybugs primarily feed on. The insects are harmless, and Erbilgin advises leaving them alone.

“It’s better if you leave them alone because next year they’ll come back stronger and might kill the pests in your backyard.”

Nature’s pest control is something Wong welcomes, and he hopes to see many more next year.

“We like ladybugs. They’re wonderful. I think everybody likes them.”