European Paper Wasp (Polistes dominulus)

What are paper wasps?

Paper wasps are closely related to yellowjacket wasps. You can tell them apart because paper wasps generally have significantly longer hind legs which hang below the abdomen in flight. Paper wasps also make smaller nests with an open, cells exposed (see photo below, right), architecture.

Paper wasps normally go about their business pretty much unnoticed. Most native (US) species make relatively small nests and locate them in out-of-the-way places. They are not aggressive so there is little threat of swarming. Paper wasps are excellent predators and unlike some scavenger yellowjackets are not interested in our picnic food.

European paper wasps are not typical paper wasps

The European paper wasp is not native to North America. It arrived in the New World sometime before 1981 appearing first in Massachusetts and has since spread westward now occurring as far west as California, Oregon and Washington. Its native range is Europe to China and is the most common paper wasp in Western Europe.

This new wasp makes a larger nest than our native paper wasp species and places these nests in more accessible places. Whereas native paper wasps build nests in high, out-of-the-way sites such as along the eves of a roof, European paper wasps build nests closer to the ground in areas where we might accidentally make contact. Numerous, hidden nests can increase the likelihood of unpleasant encounters between wasps and gardeners (see below). Finally, this wasp is such a successful colonizer that it sometimes displaces native paper wasps.

Because it is not native, the European paper wasp has experienced "ecological release" typical of other invader species that arrive without their own native predators and parasites. This has resulted in a rapid geographical spread and large populations where this wasp occurs.

Most people, even some entomologists, misidentify this paper wasp (Polistes spp.) as a yellowjacket (Vespula spp.). It is a little larger than a typical yellowjacket but smaller than our native paper wasps and has a very similar yellow over black color pattern. European paper wasp workers are not as aggressive as yellowjacket workers but more aggressive than other paper wasps.

The life cycle of European paper wasp is typical of other paper wasps and yellowjackets. Queens emerge from overwintering sites in spring to start a new nest. Once underway, queens remain at the nest to lay eggs while workers, sterile females, provision and build the nest.

European paper wasps start nest building a little earlier in spring than our native species which may account, in part, for its relative success. Nests grow throughout the summer, a batch of males, drones, is produced in the fall. Drones mate with newly produced queens. These new queens are the only members of the colony that survive the winter. Nests normally are not reused the following spring.

These photos illustrate why you are more likely to have an "unpleasant encounter" with the European paper wasp than other paper wasp species. The relatively large nest has been built in an area where unsuspecting hands might go (far left). Other paper wasp species tend to build smaller nests in more out-of-the-way places, less likely to be encountered by accident.

While this wasp certainly will sting it is unlikely to swarm thus reducing the overall threat compared to their more aggressive yellowjacket cousins.

Paper wasps are not attracted to artificial wasp traps nor will poison baits likely work because paper wasps require live prey. The only control now is to destroy individual nests as you encounter them with a Wasp & Hornet spray. Be aware, however, that this wasp is a excellent predator of many pest insects so should be left alone if at all possible.

So, while they may be annoying at times they are probably doing your garden and landscape a lot of good! In some areas, however, this wasp may be having a negative impact on rare or endangered butterflies. Eventually, this invader species will be "found" by its own set of predators and parasites and will then begin to decline in numbers.