by Ralph H Maestre BCE
Polistes dominula, Vespidae
Magic Pest Management LLC has been battling this pest in and around homes and business since the 1980s when the European Paper Wasp was first found on Long Island. Before 1981, the European paper wasp had not been recorded in North America. In its native region of P. dominula is most commonly found in those countries around the Mediterranean Sea in Europe. The wasp is also known as the Mediterranean Paper Wasp or just Meds. A highly successful colonizer, this wasp has rapidly increased its distribution in the United States during the past 30 years. Before the introduction of this new species, the northern paper wasp, Polistes fuscatus, was the most frequently encountered species in and around structures in the New York area of Brooklyn, Queens, the Bronx, and Manhattan, as well as Western Nassau County.
P. dominula is frequently mistaken for a yellowjacket. It is smaller than the native northern paper wasp; the European paper wasp (Images. 1 & 2) is yellow and black, resembling the pattern of the yellowjacket. The Med is not as aggressive as the yellowjacket nor is the nest as numerous. As in all paper wasps, the "waist" is very thin. During flight, the hind pair of legs trails below in an extended fashion, just dangling. The nest is the characteristic upside-down umbrella shape, and the open cells can be seen from below. Cream-colored larvae are legless and remain within their cells until they emerge as adult wasps.
P. dominula was first discovered in Cambridge, Massachusetts, during the late 1970s. Since then, the wasp has been recorded in northeast states of Maine, Vermont, New Hampshire, Connecticut, Rhode Island, New York, New Jersey, and several other eastern and mid-western states. It has recently been discovered on the west coast of the US.
Behavior & Life History
The previous year's fertilized queens begin new colonies of P. dominula each spring. These queens had overwintered in protected areas such as under the bark of dead trees, in hollow trees, within wall voids of houses, under siding and occasionally within the cells of a paper wasp nest. Most nests are newly constructed each year, yet the queens will sometimes use a previous year's nest, thereby establishing their colonies earlier in the season than our native species. This may be one reason they have adapted so well. The queen then starts depositing small, elongated eggs in each cell, which hatch in several days. She will feed her young larvae masticated caterpillars and other insects. The native species of Polistes prey only on caterpillars. After the first brood of larvae mature and emerge as worker females, the queen will limit her activity to laying eggs to expand the number of workers. The workers assume the duties of food collection, nest construction, and colony defense. The larvae may complete their development and become adult wasps in as little as 40 days.
Nests are constructed in protected locations such as under and within the soffits of structures, in attics, under shingles, behind shutters, and in many other enclosed areas. Some of the more notable locations where nests have been encountered include exterior lighting fixtures, parking meters, bird boxes, and infrequently used equipment like gas grills, patio umbrellas, motor homes, boats, and autos.
Speculations for the rapid expansion of the European paper wasp have included:
- Earlier seasonal establishment of colonies allowing P. dominula to establish workers before our native species, thereby benefiting foraging activities and colony expansion;
- Use of numerous enclosed nest sites, providing protection from predation;
- A more varied diet (many different genera of insects in several orders) benefits early and rapid larval development.
Impact, Damages and Concerns
European paper wasps are very attentive to potential threats to their nests. They can detect movement at 12 to 20 feet from the nest but fortunately are not very aggressive and do not typically attack unless people are very close (inches away). Since they prefer to hide their nests, this behavior increases the risk for unpleasant encounters. An unsuspecting individual may be stung while attempting to change a light bulb for an outside fixture, or while painting or removing window shutters. Furthermore, observations in New York indicate that these wasps are extremely common in urban settings.
Whenever new species are introduced into an environment there are unpredictable consequences. The increased risk for stings is an obvious. Even more troubling, it appears that this new species has had an adverse impact on the native species of Polistes, since we have seen a reduction in their numbers.
Management and Prevention
Every attempt should be made to limit suitable nest sites. Repairing holes in walls, caulking cracks in soffits and eaves, and sealing openings vents and louvers will help in preventing the establishment of nest sites. Magic Pest Management's seasonal programs looks for nests early in the season by founding queens. When found our technician easily eliminates the nest before workers are produced. Nests that have several workers can be treated. The nests located within eaves and soffits, may be treated by applying an insecticidal dust to the openings of the voids. Magic Pest Management provides this type of service to control paper wasps. A written report state the locations of these nest sites may be provided so that you, the client, may make the necessary repairs.
Image 1 and 2. P. dominula Steve Jacobs - Penn State Entomology Dept.