Why Are Bees and Wasps so Bad in the Fall?

Have you ever been at a fall tailgate and thought, “Wow, there seems to be way more wasps now than during summer?” This experience, combined with the increased interest in stinging insect treatments we see in the fall, prompted me to ask Batzner Associate Certified Entomologist Dave Kusnierek whether stinging insects really are worse in autumn or if it was just my imagination. Here is his response:

Population Size

Problems with stinging insects such as bees, hornets, and wasps do increase in the early fall, mainly because populations are at their largest size around that time of year. The size of the nest has been growing all summer, so in the beginning of fall you start to run into fully mature nests that simply have a higher population than earlier in the summer. The larger nests send out more foragers, increasing the chances that they become a bother to you.

Dietary Changes and Food Availability

During the fall, some species of stinging insects become more aggressive because they are preparing their queen for the winter, and are more protective near the hive. This aggravated behavior is made worse as natural food sources, such as flowers and insects, are depleted with colder weather, and they grow hungry. Many stinging insects also undergo a change in their dietary needs in the fall, switching from requiring proteins to requiring carbs. These factors cause stinging insects to seek out artificial food sources, leading them to become more of a nuisance around outdoor events like festivals and backyard picnics. Our own behavior can also increase run-ins with stinging insects, as doing fall maintenance around the house often leads to areas where stinging insects are likely to build nests.

The best way to stop them from becoming a major problem in the fall is by having an ongoing service to prevent the population from growing too large throughout the summer. The populations will decrease naturally once the weather gets too cold; however, it is still worth it to treat the nests in the fall. The queen will leave the nest to spend winter in a crack or void of a building, so treating the nest before this happens can reduce the likelihood of having a nest built on your property the following year.

If you experience an issue with stinging insects, don’t hesitate to contact us or call (262)797-4160 for more information on our year-round preventive or single treatment stinging insect services!