Paper Wasps
Order:
Hymenoptera
Family: Vespidae
Scientific Name:
Polistes spp.
Polistes wasps are most often referred to as paper wasps. However, Walter Ebeling Ph.D., author of Urban Entomology, suggests that they be called “umbrella wasps” for two reasons: the distinctive shape of the nest; and the fact that other wasps, such as yellowjackets and hornets, also construct paper nests, which invites confusion during identification.
While
these wasps are not typically aggressive, their propensity to construct
nests in protected areas on structures brings them in proximity to human
activity.
When humans approach these undetected nests, encounters can lead
to vicious stings.
Biology and Habits
Members of the family Vespidae fold their wings lengthwise over the abdomen, making the wings appear half their normal size. At rest, the wings are also held separately rather than one covering the other. These wasps are about ¾ inch (18 to 20 mm) in length. Coloration varies according to region: in the East, they are a dusky brown marked with orange or black and yellow; and in the West, they are more brightly colored, with orange or yellow predominating.
The nests of Polistes wasps are usually small, occupied by no more than 100 to 250 workers. The nest is constructed of a paper-like material shaped into a single layer of cells called a comb. The comb is not enclosed in a paper envelope and faces downward. The open construction of the nest makes it more susceptible to the weather, and as a result, these wasps build their nests in protected sites such as under eaves and in attics.
In harsh winter climates, mated females overwinter in protected areas, such as under bark or in wall voids. In the spring, mated queens establish the nests. The queen also forages for food, usually caterpillars or other insects, which she chews and feeds to the larvae. Paper wasps do not have a true worker caste, but other overwintered mated queens or the first group of sterile female workers to emerge can assist the dominant queen. The dominant queen remains with the nest and is the sole egg producer. Should this queen die, another mated queen can assume this role.
The
workers continue to care for the brood (that is, the eggs, larvae and
pupae) throughout the spring and summer, providing food, water and protection.
In most areas, males and
fertile females are produced in the late summer and early fall.
After mating, the colony dies off and only the mater females seek
a protected area to overwinter.
Control
When dealing with paper wasps, wear protective equipment, including a bee hat, long-sleeved coveralls, eye wear and gloves. Unlike bees, these wasps aggressively defend their nests and can inflict multiple stings. Locate the nest by examining all protected areas in the vicinity of wasp activity. Simply removing the nest will not resolve the problem, because surviving wasps will quickly construct a new one.
The best strategy is to treat the nest at night when all the workers and the queen are present. This tactic maximizes the effect of the pesticide application by killing most if not all of the wasps. If treatment is made at night, avoid shining a light directly on the nest, particularly if you are holding it, because strong light often attracts workers. You can also use a red filter on a flashlight. A wide variety of products are labeled for wasp control including dusts, aerosols and liquid formulations. Read the label prior to using the product and avoid pesticide drift.
Complete
the job by removing the nets, particularly if it is inside a structure
such as an attic. This tactic
prevents secondary infestations by dermestids or other pests.
(Courtesy of the National Pest Control Association.)