Jeffrey Hahn, Asst. UMN Extension Entomologist
As our attention finally turns to spring, there could be some loose ends to tie up from last fall. For people that experienced wasp nests in their home, they may be wondering what they should do with any wasps that may remain in them. Fortunately, there are no longer any wasps alive in those nests.
Late last summer, new queens were produced. After mating, they left the nest, and flew off to eventually find sheltered sites in which to overwinter. Meanwhile back at the nest, the old queen and workers continued with their daily routines until freezing weather killed them. Newly mated queens do not return to their old nests but instead will construct their own nests when spring begins.
So what does that mean for nests in and around your home this spring. You can largely ignore them. One exception to this would be if you experienced a wasp nest in a wall void or somewhere within the structure of your home, such that you could not see the nest but you can see wasps flying back and forth from an opening. In this case, you should seal up those openings. The reason is that while the old nest is not reused, a new nest could be built in the same space. Early spring is a good time to seal those openings before wasp queens are active and begin building new nests.
There are have also been reports of wasps indoors during mild late winter days. There has been concern that there is a wasp nest in the home and the warm temperatures are 'waking' them up. While most wasp queens will overwinter on their own, paper wasp (Polistes spp.) queens seek shelter gregariously, i.e. in nonsocial groups. It is not uncommon to see a dozen or more paper wasps but fortunately, this is not an indication of a nest. If you encounter this situation, just open the window and let them fly out or take a fly swatter or rolled up newspaper and dispatch them.