Paper wasps are 3/4 to 1 inch long, slender, narrow-waisted wasps with smoky black wings that are folded lengthwise when at rest. Body coloration varies with species: Polistes exclamans is brown with yellow markings on the head, thorax and bands on the abdomen; Polistes carolina is overall reddish-brown.
Paper wasps should not be confused with yellowjackets (Vespula squamosa Drury) and baldfaced hornets (Dolichovespa maculata (Linnaeus)). Paper wasp nests are open and cells are not covered with a cap (in an envelope).
- Paper wasps are semi-social insects and colonies contain three castes: workers, queens and males. Fertilized queens, which appear similar to workers, overwinter in protected habitats such as cracks and crevices in structures or under tree bark. In the spring they select a nesting site and begin to build a nest. Eggs are laid singly in cells and hatch into legless grub-like larvae that develop through several stages (instars) before pupating. Cells remain open until developing larvae pupate. Sterile worker wasps assist in building the nest, feeding young and defending the nest. A mature paper wasp nest may have 20 to 30 adults. In late summer, queens stop laying eggs and the colony soon begins to decline. In the fall, mated female offspring of the queen seek overwintering sites. The remainder of the colony does not survive the winter.
- Mouthparts are for chewing. Nests are built from wood fiber collected from posts and occasionally from live plant stems, causing some plant damage. This fiber is chewed and formed into a single paper-like comb of hexagonal cells. Nests are oriented downward and are suspended by a single filament. Mature nests contain up to 200 cells. Paper wasps prey on insects such as caterpillars, flies and beetle larvae which they feed to larvae. They actively forage during the day and all colony members rest on the nest at night.
- Wasps can be found on flowers, particularly from goldenrod in late fall. Paper wasp nests can be dislodged from eaves using sprays of high pressure water from a good distance, taking precautions not to allow wasps to attack nearby people or pets. Wasps will eventually abandon the nest.
- Nests commonly occur around the home underneath eaves, in or on structures and plants; wasps attack when the nest is disturbed and each can sting repeatedly; stings typically cause localized pain and swelling, but in sensitive individuals or when many stings occur (as with most arthropod stings) whole body (systemic) effects can occur including allergic reactions that may result in death; males are incapable of stinging because the stinger on the females is a modified egg-laying structure (ovipositor) and it is not present in males; wasps feed on insects, including caterpillar pests, and thus are considered to be beneficial insects by many gardeners.