The length of P. fuscatus ranges from 15 to 21 mm . These wasps are very slender and have a waist connecting the thorax and the abdomen. They are a dark reddish-brown color, and the body is segmented by yellow bands. Their pointed heads distinguish them from yellow jackets. In males, the tips of the antennae are strongly curved, and there is more yellow marking the front of the head.
Females of these wasps have a venomous sting. (Milne, 1980)
Polistes fuscatus queens lay fertilized eggs into individual cells within the nest. The larvae which subsequently hatch from these eggs are fed and protected by the queen and subordinate females until they are ready to pupate. The larvae are then covered with a silky covering. The first generation emerges from pupation as into smaller, infertile females. These are the true workers of the colony. Later in the life of the nest, males and fertile female offspring are produced. The fertile female offspring are the next generation of queens. They survive the winter and start new nests the following year. (Lyon and Wegner, 2001)
Males and females mate at the end of the summer, after the nest has been abandoned. Venom from females acts as an attractant for males, drawing them from at least 2 meters away. (Turillazzi and West-Eberhard, 1996)
The mating season for P. fuscatus is during the spring and summer. Fertile females are hatched towards the end of summer and they mate with males. With the onset of winter, the old queen, workers, and males die and the young females enter hibernation. They emerge in spring to build nests and produce offspring. (Evans, 1963)
The lifespan of P. fuscatus is approximately one year, or the time it takes a queen to develop and to mate. Larvae from that are laid during the summer are well fed because of abundant food, and are capable of becoming queens. These eggs hatch before fall and the resulting offspring hibernate during fall and winter. The new queens emerge in the spring to begin nests and lay eggs. By fall, after laying eggs that will develop into new queens, these queens die. All accompanying workers and males die with the queen. (Evans, 1963; Unknown, 2001)
Polistes fuscatus is social and has complex societies based around a single queen. One fertile female begins building a nest after hibernating for the winter. Other fertile females begin working with her but the original female's dominance is accepted. Once the nest is built, the queen can drive the co-foundresses away or relegate them to worker status. These secondary females are still fertile, but the queen eats the eggs laid by these females as part of the assertion of her own dominance as the queen. The first offspring produced by the queen are infertile females who are not capable of becoming queens. These are the true workers as they do not pose a threat to the queen and can do nothing but build the nest and care for the young. Although a queen does lay eggs capable of becoming fertile females, she does so late in summer so that they can hibernate during winter and become queens or co-foundresses in the spring.
The division of labor in this species is related often to age. Younger wasps are somewhat pampered, receiving food and the paper used to build the nest, whereas older wasps have to forage for paper and feed the larvae. (Evans, 1963; Grzimek, 1972; Naug and Gadagkar, 1998)
As social wasps, P. fuscatus must have communication avenues for nest and hierarchy building and for defense. In order to establish dominance, a queen adopts a series of threatening postures that cause her underlings to subordinate themselves.
A chemical producing gland towards the posterior portion of the wasp produces a chemical that separates eggs laid by the queen from eggs laid by workers. The queen uses this chemical to decide which eggs to eat and which eggs to allow to grow.
Outsiders, even conspecifics, are not well-received in an existing nest and are quickly removed. As an outsider cannot be discerned visually or through tactile sensation, P. fuscatus relies on chemical cues. Pheromones are released by the wasps and the pheromones are specific to each nest. The specific chemicals are acquired upon birth by the wasps. It is extremely difficult for an individual to become accepted into a neighboring colony, unless it establishes a new colny of its own. (Evans, 1963; Gamboa, et al., 1996; Turillazzi and West-Eberhard, 1996)
Adult P. fuscatus feed mainly on plant nectar. The species is considered insectivores because it kills caterpillars and other small insects in order to provide food for developing larvae. Foragers collect various prey insects to feed to the larvae. The wasp then malaxates, or softens the food and in doing so absorbs most of the liquid in the food. This solid portion is given to older larvae and the liquid is regurgitated to be fed to younger larvae. (Turillazzi and West-Eberhard, 1996; Turillazzi and West-Eberhard, 1996)
Polistes fuscatus is eusocial but its social organization is not as rigorous as other eusocial organisms. Whereas in some other eusocial insects, guard polymorphs have developed that specialize in nest defense (e.g. soldier termites), paper wasps have only workers and queens. These two classes work together to fend off nest predators and parasites.
Two trends have been found in the study of anti-predator adaptions in P. fuscatus. The first is that the queen is the most aggressive defender of the nest and the second is that aggression in both workers and queens increases with the passage of time. These two adaptations reveal the incomplete eusocial nature of P. fuscatus. The queen is the most aggressive because she has a huge reproductive investment in the nest. The workers become more aggressive with time since their investment increases with time. (Evans, 1963; Judd, 2000)
Wasps feed on the nectar of plants and in doing so, they transfer pollen from one plant to another, aiding in plant reproduction. They are thus essential to ensure that plants reproduce. To the extent that these wasps fall prey to other animals, they affect the survival and reproduction of those predators. Polistes fuscatus also affects species upon which it preys in order to feed larvae. (Unknown, 2001)
Polistes fuscatus feeds on various garden insects. The wasps feed on caterpillars and these insects also serve as major sources of food for the eggs. Organic gardeners benefit greatly from these wasps because they eliminate the need for pesticides. ("Paper Wasps (Polistes species)", 1995; Unknown, 2001)
Due to the proximity of the wasps to humans and their habitation in houses and other buildings, they can prove hazardous. They can inflict stings on domestic animals in places such as barns where they may have nests. Humans are also at risk of aggravating these insects and suffering from stings.
Polistes fuscatus is one of the most common wasps in North America and the one that is very well studied due to its steady population sizes, therefore there is no cause to worry about the status of this species.
Nancy Shefferly (editor), Animal Diversity Web.
Khushdeep Grewal (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
living in landscapes dominated by human agriculture.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
helpers provide assistance in raising young that are not their own
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
the condition in which individuals in a group display each of the following three traits: cooperative care of young; some individuals in the group give up reproduction and specialize in care of young; overlap of at least two generations of life stages capable of contributing to colony labor
parental care is carried out by females
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
fertilization takes place within the female's body
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
chemicals released into air or water that are detected by and responded to by other animals of the same species
breeding is confined to a particular season
remains in the same area
offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
places a food item in a special place to be eaten later. Also called "hoarding"
living in residential areas on the outskirts of large cities or towns.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
living in cities and large towns, landscapes dominated by human structures and activity.
an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).
uses sight to communicate
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Gamboa, G., T. Grudzien, K. Espelie, E. Bura. 1996. Kin recognition pheromones in social wasps: combining chemical and behavioral evidence. Animal Behavior, 51: 625-629.
Grzimek, B. 1972. Grzimek's Animal Life Encyclopedia. New York: Van Nostrand Reinhold.
Judd, T. 2000. Division of labour in colony defence against vertebrate predators by the social wasp *Polistes fuscatus*. Animal Behavior, 60: 55.
Lyon, W., G. Wegner. 2001. "Paper Wasps and Hornets" (On-line). Ohio State University Extension Fact Sheets. Accessed 10/11/01 at http://ohioline.osu.edu/hyg-fact/2000/2077.html.
Milne, L. 1980. The Audubon Society Field Guide to North American Insects and Spiders. New York: Knopf.
Naug, D., R. Gadagkar. 1998. The role of age in temporal polyethism in a primitively eusocial wasp. Behavioral Ecology and Sociobiology, 42: 37-47.
Turillazzi, S., M. West-Eberhard. 1996. Natural History and Evolution of Paper-Wasps. New York: Oxford Science Publications.
Unknown, 2001. "Paper Wasps" (On-line). MSN Encarta Premium. Accessed October 11, 2001 at http://encarta.msn.com/encyclopedia_761582488/Paper_Wasp.html#p7.