Ladybug Legion: Why Alberta's Polka-Dotted Pests Are Sticking Around This Fall

Calgary and other parts of southern Alberta are experiencing an unusually high number of ladybugs this autumn, prompting residents to wonder about the sudden surge of these familiar, polka-dotted insects. While their presence might seem like a charming, albeit overwhelming, natural phenomenon, experts confirm it's a completely normal occurrence tied to specific environmental factors.

Shelley C.

Pruss, a senior conservation outreach and education specialist with the City of Calgary, explained that the ladybug boom is largely due to a combination of warm weather and an abundance of aphids, their primary food source. "Last spring and summer, we had lots of moisture and lots of warm weather, and that created an abundance of their food source, which are aphids," Pruss stated.

This plentiful food supply allowed ladybug populations to flourish throughout the warmer months, leading to a noticeable increase in their numbers as temperatures begin to drop.

As fall progresses and the weather cools, ladybugs, like many insects, begin their search for suitable overwintering sites.

They are attracted to warm, sunny areas, often congregating on the south or west-facing sides of buildings. This natural instinct to seek shelter is what brings them into closer contact with homes and urban areas. Pruss emphasized, "They're coming out looking for somewhere warm to spend the winter, and our houses look like great cliffs or caves for them to do that." This behavior explains why residents might find large clusters of ladybugs on their windows, walls, and even inside their homes.

While the sheer volume of ladybugs can be a nuisance, especially when they enter homes, they are generally harmless to humans.

They do not sting, spread disease, or cause structural damage. In fact, ladybugs are beneficial insects, acting as natural pest control by preying on aphids, which can damage gardens and crops. Their presence indicates a healthy ecosystem where their natural predators are thriving.

For those looking to manage the influx, Pruss advises against using pesticides.

Instead, she recommends gentle methods for removal, such as sweeping them up or using a small handheld vacuum to collect them. Once collected, they can be released outdoors in a sheltered area where they can continue their search for a winter home. Sealing cracks and gaps around windows and doors can also help prevent them from entering homes.

The ladybug boom is a fascinating reminder of nature's cycles and the delicate balance within our local ecosystems.