What to know
- Wasps seem to be everywhere in late summer. They buzz around your food and drinks, get into your trash, and ruin sunny beach days.
- Karen McDonald at Toronto Region and Conservation Authority says wasps develop in the spring, so by the time late summer comes around, wasps have run out of fruit and plant nectar.
- In their effort to search for food, wasps target outside food sources, like our sugary colas, snacks, and even our garbage.
In late summer and early fall in Toronto, wasps are seemingly everywhere. They buzz incessantly at the beach, inside garbage cans, and near sugary drinks and food.
A relaxing day near the lake suddenly doesn’t feel all that tranquil anymore when you’re constantly swatting wasps from your personal space. But although wasps are annoying to humans, they still serve a purpose and are vital to maintaining healthy ecosystems.
To learn more about wasps’ role in pollination, insect control, and food production, Now Toronto reached out to Karen McDonald, the senior manager of restoration and infrastructure at Toronto Region and Conservation Authority.
McDonald acknowledges that while wasps aren’t as effective as bees at pollinating, they’re far better at helping regulate pest populations.
“Wasp larvae require protein-rich meat, which adults provide by hunting and killing a wide variety of insects and spiders,” she explains. “This helps to regulate pest populations and indirectly supports food production since many of their prey are agricultural pests.
Additionally, some wasp species are parasitoids, which means they lay their eggs inside other insects. During development, the larvae “eat” the host, further contributing to population control.
Social wasps develop in the spring
There are two types of wasps: social wasps and solitary wasps. Social wasps are the ones that make drinking a can of pop nearly impossible. McDonald says social wasps are more aggressive in late August and early September because their development period starts in the spring.
“Social wasp colonies start developing in the spring, and the size of their colonies grow over time,” she says. “Over the summer, the queen’s egg-laying declines and the amount of larvae in the colony decreases.”
As there are fewer wasp larvae to provide adult wasps with the sugary liquid — like flower and nectar sap — for necessary carbohydrates, outside food sources become their new target.
This is why the insects are so attracted to ripe fruit, sugary drinks, uncovered meals, and garbage cans at the end of summer.
“The combination of fewer larvae providing food rewards, increased independent foraging, abundant workers, and heightened nest-defense behavior makes encounters with wasps much more common and can make them appear considerably more aggressive in late summer/early fall,” McDonald says.
How to avoid being stung
While the majority of wasps don’t sting, social wasps can be more aggressive during this transitional season. To keep exposure to a minimum, McDonald suggests covering up food and drinks, tightly sealing garbage and compost bags, and removing fruit that has fallen onto the ground.
Another tip involves strategically placing wasp traps can also be helpful. Putting traps away from frequently accessed areas like patios and walkways can lead wasps to gather elsewhere.
