Why Are Wasps Aggressive in Late Summer?

Author: Emma Grace Crumbley, Entomologist 

When you think of insects you don’t want to mess with, I bet wasps come to mind. They buzz really loud, they fly really fast, and they sting really… well, they sting. Even as a lifelong insect lover, my worst interactions with bugs have involved the surprise and pain of being stung by wasps.

While some wasps don't sting unless provoked, wasp species like yellow jackets, paper wasps, and bald-faced hornets are always ready to attack even the most minor threats to their colony. But as the summer drags on, it seems like wasps of all kinds become more aggressive.

Maybe it's the hot weather that gets them angry. I know I'm more irritable when it's 90-plus degrees out, and the slightest inconvenience interrupts my day. Yes, warm weather provides insects energy to fly and forage for food, but it also puts stress on the colony. More energy to fly means more foraging can be done. More foraging means more food is collected, and more food means more larvae can develop. Overcrowding in wasp colonies combined with territorial foraging leads to lots of wasps leaving the hive looking for food and stinging anything that gets in their way.

It could also be that wasps can sense the season changing and realize their food security is running low. Wasps are omnivorous scavengers and pollinators, feeding on fruits, flowers, nectar, other insects, and carrion. It may be that the late summer heat reduces their food sources, making wasps more desperate to find food for their nest. Flowers stop blooming at the end of their season, other insects begin to hibernate or migrate, and dead animals get eaten by bigger scavengers who are also desperate for food at the end of the season.

In any case, those aggressive wasps you saw at the beginning of the summer are undoubtedly getting more agitated as the season progresses.

Buzz Off, Wasps!

But don’t let wasps ruin the last days of summer. Take the guesswork out of pest work and call Mosquito Squad! Our Squad Home Shield pest package can help manage your wasp problem and prevent future infestations. Call today for a free quote! Services vary by location.