Most paper wasps measure about 2 cm (0.75 in) long and are black, brown, or reddish in color with yellow markings. Paper wasps will defend their nest if attacked. Adults forage for nectar, their source of energy, and for caterpillars to feed the larvae (young). They are natural enemies of many garden insect pests. A widespread North American species is the golden paper wasp.
The nests of most species are suspended from a single, central stalk and have the shape of an upside-down umbrella. Plant and wood fibers are collected by the wasps, mixed with saliva that is formed into the thin cells of the nest. The nests are constructed in protected places, such as under the eaves of buildings or in dense vegetation. Normally a colony of several to several dozen paper wasps inhabit the nest.
The colony is founded in early spring, soon after the queens (mated females) emerge from hibernation. As the colony matures, males and the next year’s queens are produced. These queens mate with males and are the only members of the colony to survive through winter. In late summer or fall, the founding queen, workers (unmated females), and males all die. The newly mated queens hibernate, typically in piles of wood, in vegetation, or in holes. The following spring they emerge and begin the cycle anew.
In most temperate species of paper wasps, colonies are founded by one female who dominates the colony and lays most of the eggs. This female constructs the nest, lays eggs, forages, and raises the first generation of offspring. She then stops foraging, becomes the queen, and rules by dominating her offspring of workers. If the queen dies or is otherwise lost, the most aggressive worker takes over. This worker begins laying eggs and continues to dominate all below her. Since the workers have not mated, they can only lay unfertilized eggs, which develop into males, a typical trait in wasps.