This birdhouse is one of the finishing touches on the garden. It’s not really placed to attract nesting birds; it’s too low and too close to the path. So, the reasoning was that it would just be another piece of garden art, occupied by spiders.
The day after installation, I noticed something fly out of the bird house. I waited. Something flew in. Something yellow, tiny and insectoid. It flew in a straight line, as if it knew exactly where it was going, like it had been there many times before . I approached the bird house. A wasp!
Alas, it’s not a native wasp. Another invasive species from elsewhere. These are European Paper Wasps, Polistes dominulus. The adults are pollinators, feeding on nectar. They’re also predators, capturing caterpillars and other insects to feed their young. They will build a nice paper nest inside the bird house, breed worker wasps to develop it, then die off in fall, leaving only a few wasps to continue the species. Our native paper wasp is Polistes fuscatus aurifer, a species that apparently does not like bird houses so much as its European cousin.
So now the question is to leave the wasps alone or kill them. If we do kill them, that still won’t guarantee that a population of the native Polistes fuscatus aurifer will move in, and it’s unclear how much ecological damage the new species will do. It does capture all kinds of insects, unlike P. fuscatus which hunts only caterpillars. But this is not necessarily a bad thing, either. We don’t know how aggressive they are – supposedly someone standing several feet from the nest will not be bothered.