Polistes fuscatus

P. fuscatus is a part of the order Hymenoptera, the suborder Apocrita, the family of Vespidae, and the subfamily Polistinae, the second-largest subfamily within the Vespidae, of which all are social wasps. The Polistinae comprise four tribes, including Polistini, Epiponini, Mischocyttarini, and Ropalidiini. It is characterized by two major behaviors: colony founding and reproductive dominance. A study in which bootstrap analysis was conducted concluded that the narrower definition of P. fuscatus is part of the New World subgenus Fuscopolistes. In addition to P. fuscatus, Fuscopolistes includes separate species concepts for P. bellicosus, P. apachus, P. aurifer, P. carolina, P. dorsalis, and P. metricus, all of which are the closest relatives of P. fuscatus. ==Description==

The length of P. fuscatus often ranges between . The fore wing length ranges between ; in general, the fore wing of males is above , whereas females have a fore wing length above . The physical characteristics of the P. fuscatus are highly dependent on the geographic location of its habitat. Throughout the United States, three color pattern trends represent different regions throughout the country. The male is identified by its darkened apical flagellomeres in addition to its darkened dorsal surface of the apical flagellomeres that is common to other species of wasps. Many southern P. fuscatus individuals, however, have additional markings and may resemble wasps of other species. The facial and abdominal markings of P. fuscatus are highly variable, including a variety of different patterns, such as small dots, long stripes, clypeus blotches, yellow abdominal dots, upper clypeus stripes, and combinations of both clypeus edge and tip colorations. Furthermore, some wasps have these facial and abdominal patterns in brown and black instead of yellow. These marking colors, however, are often influenced by the geographic location of the wasp. File:Day 268 - Paper Wasp - Polistes fuscatus, Meadowood Farm SRMA, Mason Neck, Virginia.jpg|P. fuscatus from Virginia with brilliant red and yellow concentric abdominal spots File:Polistes fuscatus.jpg|P. fuscatus from Illinois with a striped abdomen and red abdominal spots File:Northern Paper Wasp - Polistes fuscatus, Anhinga Trail, Everglades National Park, Homestead, Florida.jpg|P. fuscatus from Florida with a black solid abdomen and red spots File:Northern Paper Wasp (Polistes fuscatus), Cantley.jpg|P. fuscatus from Quebec with yellow abdominal spots and stripes and no red markings File:Vespidae - Polistes fuscatus.JPG|P. fuscatus from Quebec with yellow abdominal stripes, lacking both spots and red markings ==Distribution and habitat==

''Polistes fuscatus's'' distribution along the eastern half of North America ranges from southern Canada to the United States. ==Lifecycle==

The lifecycle lasts about one year. In early spring, the new foundress emerging from diapause starts a new colony, building an umbrella-shaped nest made of a papery material and suspended from a single stalk. The foundress lays eggs into individual cells. The first generation is composed of infertile female workers. In the next generation, multiple foundresses are hatched with communal nests, but the other fertile females accept the dominance of a single female and raise offspring cooperatively. Later in summer, the next year's foundresses are produced, and they mate with males. The newly mated foundresses hibernate in winter, while old founding foundresses, workers (sterile females), and males die. ==Colony cycle==

Colony stages can be separated into three stages based on nest content: pre-emergence (nest initiation to first adult), emergence-enlargement (emergence of first adult to beginning brood decline), and post-enlargement (no further new cell addition). The total number of wasps in the colony can be well over 200. The mean of the pre-emergence stage is about 48 days long; it includes the egg, larval, and pupal stages and may also be affected by nutrition and temperature. The first eggs that are laid are all female workers that can care for future reproductive females. After the first eggs are laid, both male and female eggs are laid until mid-September; the laying of male eggs has been shown to be correlated with increased oviposition rate of the dominant females. After the hatching of both male and female eggs, only female adults emerge, though eggs laid after the end of July no longer emerge and reach adulthood. The foundress disappears at the end of July, which is when both the number of laid eggs and the rate at which the nest grows decline, though other reproductive females may continue to lay eggs. The brood itself begins to decline towards late August, thus leading to the conclusion that brood declination occurs when reproduction no longer occurs. After reaching the post-enlargement behavior, brood destruction occurs in which wasps begin exhibiting abortive behavior by either throwing larva out or feeding them to existing nest mates; if not aborted, these larvae eventually emerge as abnormal adults. After this destruction, the adult wasps abandon the nests. Prior to hibernation, the wasps cluster together in aggregations to mate and then begin hibernation until the next season. ==Behavior==

Polistes fuscatus is an eusocial organism that has a hierarchical social system usually centered around one foundress. Although this species is classified as eusocial, its social organization is not as evolved as other eusocial organisms. Foundress-initiated interactions can be placed into two broad categories: solicitations and non-solicitations. Solicitations include “receipt of water, nectar, pulp, or prey from returned foragers,” while non-solicitations include, “antennation, lunging/bumping, chasing, grappling, and biting”. Foundresses spend substantially less time off the nest compared to workers. Workers vary significantly in time spent off the nest, which correlates with foraging efforts. More dominant workers spend less time off the nest compared with less dominant workers. Other eusocial insects, such as soldier termites, have developed guard polymorphs that specialize in nest defense. Paper wasps on the other hand, have only workers and foundresses who defend the nest together. The foundress is the most aggressive defender of the nest since she has the most reproductive investment. In some cases, Polistes fuscatus has been shown to share nests with a closely related species, Polistes metricus. Dominance Polistes fuscatus has a linear dominance hierarchy that revolves around the fertility of each individual wasp; those that are more dominant within the nest generally have the larger or more developed ovaries. Researchers found that when Polistes fuscatus paper wasps live isolated, their anterior optic tubercle, the area responsible for processing visual colors, grows more relative to mushroom body. Moreover, they lose the ability to recognize other paper wasps' colored faces. Colony defense A greater part in the division of labor in colony defense is given to the foundress of the colony. Foundresses may be less tolerant of intruders compared to other colony members due to the consequences of accepting non-nest mates into the colony. Water is used for the following processes: nest cooling, construction, and metabolism; plant fibers are used for construction, and carbohydrates and protein is used as food and energy. Water is a vital resource for wasps given its many capabilities, and many wasps will go to a variety of places to obtain it, such as puddles and ponds, or even drinking fountains and faucets. Wasps are able to obtain water by imbibing it and regurgitating it once they return to the nest and are able to use it for construction by mixing it with the masticated plant fibers. These plant fibers are collected from dead wood. By mixing the plant fibers with water, wasps are able to create pulp which is then used to help the construction of nests. Polistes fuscatus is considered to be a generalist prey forager, but may also act as a specialist due to its habit of commonly returning to a specific location or to prey on the same species. They use the scavenged animal protein from both vertebrates and arthropods such as: caterpillars, flies, alate ants, termites, spiders, bees, and other wasps to help the development of their brood. Social wasps collect carbohydrates from nectar, sap, and fruits and may store them within the nest; some wasps may even steal or consume carbohydrates from other carbohydrate foraging or making arthropods. Although the foraging of social wasps is not as developed as some other arthropod species given its weakness in recruitment, the ability to communicate to nest mates of the location of a resource stronghold, it may impact the greater ecosystem. Diet Polistes fuscatus eats arthropod prey, animal proteins, carbohydrates and protein. They will eat caterpillars, flies, ants, termites, spiders, bees, and other wasps. Carbohydrates may include nectar, sap, and fruits. Differential egg eating Egg laying by subordinate females and the oophagy of these eggs by dominant female wasps will occur until two weeks after the first female eggs emerge. Prior to these two weeks, egg layers will continuously eat other female wasps’ eggs approximately eleven minutes post being laid; however, no egg layers would ever eat their own eggs, indicating that they could recognize their own individual eggs. It can be conjectured that subordinate egg layers could not lay eggs as quickly as dominant egg layers given the dominant egg layers’ greater supply of ova from the subordinate egg layers indicating that oophagy and oviposition occur close together. Previous studies have also shown that subordinate egg layers may no longer lay eggs after associating with the higher-ranking females after a certain period; this is probably due to the necessity of expending energy during foraging and inability to invest as much into their own eggs. ==Sexual behavior==

Mating Prior to hibernation, males and females will undergo mating; they will aggregate together in sunlit areas that are relatively higher in location. Reproduction The mating season for Polistes fuscatus is during the spring and summer, after the nest has been abandoned. Venom is released by females that contains a sex pheromone that induces copulatory behavior in males. The continual release of the venom causes males to try to copulate with females when they are unreceptive on the nest, thus interrupting the activities of the colony. After mating has occurred, the foundress will lay an initial generation of infertile female workers. Later on in the life of the nest, male and fertile female offspring are produced. The eggs capable of becoming foundresses are laid during the summer. Laying these eggs during the summer ensures that the larvae are well-fed due to the great environmental conditions and abundance of food. These eggs hatch before fall and the resulting offspring hibernate during fall and winter. This is surprising since there are many advantages of inbreeding for haplodiploid organisms. In Polistes fuscatus, the sex ratio is usually 1:1 for several reasons. First, males generally leave the nest to scout for mates soon after they reach adulthood, promoting population competition for mates. Second, the number of workers within a colony is relatively small (generally less than 40) making it less likely for a worker to confront the foundress. Also, since colonies are annual and workers are reared by the foundress's subordinate foundresses, the foundress can manipulate how much food they receive as larvae. Polistes fuscatus foundresses likely mate with multiple males so that the relatedness of workers is less than if they all shared the same father's genes. Finally, in the second generation of the foundresses offspring, males are usually reared earlier than reproductive females. Thus when the workers have the opportunity to bias the sex ratio, there are few male larvae present. Additionally, the males have usually completed part of their development, giving them a higher reproductive value than new eggs. Thus the costs of destroying male larvae or replacing the male larvae with their own eggs is not worth the investment. ==References==