Understanding Wasps: Their Summer Surge and How to Cope

As warm weather settles in, wasps have become a noticeable presence at outdoor gatherings and public markets across Canada. These insects, particularly yellowjackets and hornets, are actively seeking food at barbecues, picnics, and food stands. Their numbers can seem overwhelming, but experts suggest that their activity level is typical for this time of year.

Darryl Gwynne, an emeritus professor of biology at the University of Toronto, indicates that more comprehensive data would be necessary to determine if wasp populations have changed significantly over the years. “I suspect it’s simply the time of year for their activity, and they’re out there doing their thing,” he stated in an interview with CTV News. Wasps generally peak in number around July, when their nests are fully developed and they are actively foraging for food.

During this period, the worker wasps—those that do not reproduce—are most visible. They are particularly attracted to sugary foods and beverages, which helps fuel their energy. Gwynne advises that it is essential to keep sugary drinks covered to prevent wasps from getting inside.

Wasp Lifecycle and Seasonal Behavior

The lifecycle of wasps plays a significant role in their visibility. During the summer months, wasp queens remain in their nests, while their workers venture out. In early spring, the visible wasps are typically queens, as the worker population has not yet hatched. Understanding this can help individuals recognize when to expect wasps.

Wasps are ectothermic, meaning their body temperature relies on external conditions. Gwynne describes them as an annual species, with most of the population dying off after the first frost each year. The queens, however, survive the winter by mating and hibernating in leaf litter or log piles. “They store the sperm in special sperm-storing pouches and burrow down until spring when they start their nests,” he explained. If the weather remains warm into the fall, wasps may continue to be noticeable for longer periods.

Research conducted by Gwynne in New Zealand indicates that yellowjackets will expand their nests as long as the weather allows. He noted, “We really are lucky that we get severe frosts here in October or November, which helps reduce their numbers.” Without early frosts, the wasp population could potentially grow unchecked.

Identifying and Managing Wasp Nests

Recognizing wasp nests can be crucial for managing their presence. Nests vary in shape and location. For example, a paper wasp’s nest resembles an upside-down umbrella, supported by a single stalk, while bald-faced hornets create large, paper-like nests that can resemble footballs. Yellowjacket nests typically have a single opening and can be found either above ground or underground in various locations, such as trees and woodpiles.

If wasps become a nuisance on a property, experts recommend seeking professional assistance to handle the situation safely. To reduce the attraction of wasps, it is advisable to remove leftover food and vegetation from gardens and avoid leaving out meats or sugary drinks, as these smells particularly attract them.

Dr. Andrew Young, an assistant professor at the University of Guelph’s School of Environmental Sciences, emphasizes caution around nests. “If there’s a wasp nest in a tree, it’s only going to be there for one year. They don’t survive multiple years, so I give them their space,” he advised last year.

As summer continues, understanding wasps and their behavior can help individuals enjoy outdoor activities without the added stress of these persistent insects. By taking preventive measures and being aware of their lifecycle, communities can coexist with these critters more effectively.