Northern paper wasp, Polistes fuscatus
European paper wasp, Polistes dominula
Paper wasp nests consist of a single layer of cells not enclosed within a paper sheath. Nests tend to be located in protected sites such as under eaves, exterior corners of windows, vent louvers, beneath decks, and uncapped fence poles. Chain link fence protectors are another potential nest site.
Paper wasps are social insects, living in colonies of dozens of workers. Like other social wasps, paper wasps vigorously defend their nest against threats such as people who get too close to the nest entrance. Guard wasps stationed near nest entrances use chemical communication to warn the colony of intruders. Wasps can quickly emerge from a nest and attack people or animals that venture too close. Some individuals may have an allergic reaction to wasp stings, including anaphylactic shock.
The European paper wasp was discovered in the early 1980s in Massachusetts and is now widespread in the United States. There is some concern that this introduced wasp may be displacing native species.
The objective of a paper wasp management program is to reduce human encounters with the wasps, but not to eliminate them from the entire area, since they are beneficial predators of insects. The two most productive and least environmentally destructive ways to do this are to modify the habitat to reduce access to food in the vicinity of human activities and to use physical controls such as nest removal.
Paper wasps are generally more docile than other wasps such as yellowjackets and hornets. Here are a few tips for preventing or minimizing stings:
When a paper wasp nest is spotted, it is best to stay away and have a professional remove it at night.
Remove nests in locations where they pose a threat to humans, on buildings, or in playgrounds. Because wasps are predators on other insects, it is not necessary to remove nests in remote locations.
Beginning in the spring when queen wasps initiate nests, search probable nest locations. Check areas where nests have been built in the previous year. Knock down start-up nests with a pole or stream of water. Since only the queen is present, the stinging risk is much lower than later in the season when large numbers of workers are present. Doing inspections and nest removal twice a month through July will greatly reduce the number of large nests present when school opens in August or September.
Keep lids of garbage cans and dumpsters closed. Cover foods outdoors.
Typically these wasps are considered beneficial insects as they can prey on other landscape pests.
Several general-use pesticides are available. These "wasp sprays" deliver the pesticide in a stream up to 20 feet long, allowing the applicator to keep a safe distance away from the nest. Apply sprays at night when the majority of the colony is in the nest. Using pesticides on individual workers is not an effective control measure.
Conduct an inspection around the building periodically, ideally two times a month from May through September, in most areas of the country.