Polistes annularis is a species of paper wasp found throughout the eastern half of the United States. This species of red paper wasp is known for its large size and its red-and-black coloration and is variably referred to as a ringed paper wasp or jack Spaniard wasp. It builds its nest under overhangs near bodies of water that minimize the amount of sunlight penetration.Queller, David C., and Joan E. Strassmann. "Reproductive success and group nesting in the paper wasp, Polistes annularis." Reproductive Success: Studies of Individual Variation in Contrasting Breeding Systems, 1988, p. 76-96. It clusters its nests together in large aggregations, and consumes nectar and other insects. Its principal predator is the ant, although birds are also known to prey on it. Unlike other wasps, P. annularis is relatively robust in winter conditions, and has also been observed to store honey in advance of hibernation. This species has also been used as a model species to demonstrate the ability to use microsatellite markers in maternity assignment of social insects.
Taxonomy and phylogeny The first description of P. annularis was published by Carl Linnaeus in his 1763 Centuria Insectorum, where he named the species Vespa annularis. It was moved to the genus Polistes by Johan Christian Fabricius in 1804, two years after Pierre André Latreille had erected the new genus. Within the genus Polistes, P. annularis is placed in the New World subgenus Polistes (Aphanilopterus), which contains 52 species, including its allies P. exclamans, P. bahamensis, and P. erythrocephalus. Members of this subgenus are noted for their slender first abdominal segment and often orange antennal tips. The subgenus Aphanilopterus, including P. annularis, diverged from the sister subgenus Fuscopolistes (including the common P. bellicosus, P. carolina, P. metricus, and P. fuscatus) between 10 and 80 million years ago. The genus Polistes is placed in the monotypic tribe Polistini within the subfamily Polistinae (paper wasps). Polistinae contains two main behavioral groups: wasps which form nests with large number of workers, and those wasps which found nests with few workers and foundresses (the latter including P. annularis). This subfamily likely arose in the mid- to late Jurassic period, around 145 to 175 million years ago. Polistinae is further placed within the Vespidae as its second-largest subfamily. Other sister members of Vespidae include the yellowjackets, hornets, potter wasps, mason wasps, and pollen wasps.
Etymology The genus name Polistes is most likely derived from the Greek polistēs (πολιστής) which is translated as “founder of a city”. The specific epithet comes from the Latin word ānnulāris, an alternate spelling of ānulāris. The root word ānnulus is a noun, meaning 'ring', and -ālis is a suffix that modifies a noun into an adjective. Together, the word ānulāris means "ringed", "ring-shaped", or "annular".
Description and identification
Polistes annularis, as a member of the subgenus Polistes (Aphanilopterus), has a narrow first metasomal segment and bright orange antennal segments. Within its range of the eastern United States, these traits are shared with its allies P. exclamans and P. bahamensis. The coloration of P. annularis typically includes a ferruginous (rust-red) head and thorax and a mostly black abdomen with a single, prominent yellow ring and the end of the first segment. There is geographical variation in coloration between northern and southern populations. In the north, the thorax of P. annularis has ferruginous (rust-red) markings on a predominantly black background, while in the south, the thorax is mostly ferruginous, with black markings. The legs also vary from black to ferruginous. In terms of size, the fore wings are long in females, and long in males.
Polistes annularis can be separated from darker members of P. bahamensis, a species only overlapping from Florida to Louisiana and North Carolina, by the lack of yellow markings on its mesopleuron, less developed yellow markings on the mesosoma, and the lack of additional apical yellow bands on the tergum. Similarly colored members of the subgenus Fuscopolistes, including P. metricus and darker forms of P. fuscatus, can readily be separated by the lack of contrasting orange antennal tips and the wider first metasomal segment.
While many other North American Polistes species show sexual dimorphism in coloration, P. annularis and P. erythrocephalus rather uniquely do not. Within these species, the males lack extensive yellow markings on the face, and instead both males and females are red-faced. Instead, sexual determination must rely entirely on structural differences. The females are identified by having 12 antennal segments and 6 abdominal segments whereas the males are identified by having 13 antennal segments and 7 abdominal segments.
In the genus Polistes, the lateral mandibular groove is smaller in size than in other genera of social wasps. This groove is associated with the mandibular gland and sac-like gland reservoir used for salivary production. Their larvae have labial glands, which produce silk.
Distribution and habitat Polistes annularis is found throughout the eastern United States from New York to Florida, west to a line from South Dakota to Texas. This range is similar to that of P. metricus, with which P. annularis is a Müllerian mimic.
Polistes annularis forms its nests on the branches of trees and shrubs, as well as in sheltered parts of some buildings. However, it is also known to group its nests in large colonies called aggregations. These tend to be built on the underside of overhangs that block exposure to sunlight for most of the day, such as rocky cliffs, in close proximity to bodies of water, primarily riversides. These overhangs are a limiting factor to nest building. The nests differ markedly from those of other species in the genus Polistes. They are much larger, with around 500 cells, and are wide, rather than the slender, elongated nests seen in some other species. P. annularis construct nests made of paper that have cells exposed to the external environment.
Colony cycle
During the springtime, mated foundress wasps emerge from hibernation within cracks of rocky cliff walls. Returning to the area of their natal nests from the previous year, they begin construction of new paper nests typically within a few meters of their natal nests, though generally without reusing the cells of the old nest. A single nest may be built by a group of foundresses, termed "associations", which are usually came from the same natal nest. This group averages at five foundresses though may vary from a single foundress to an association of up to 22 cooperating foundresses. Of this association, a single foundress establishes a dominance hierarchy, with the dominant foundress laying the majority of the eggs.
Meanwhile, the others construct the nest, from plant fibers, combined with oral secretions, to make a papery pulp that is formed into cells. The nest is attached to an overhang by a stalk-like pedicel, composed of oral secretions including proteins rich in glycine, proline, alanine, and serine, common components of the silks of other insects. Another minor component is N-acetylglucosamine, which is probably bound to the pedicel protein. Proline is a major component of structural proteins and likely contributes to the structural strength of the pedicel in holding up the rest of the nest. The pedicel suspends the nest high in the air and precludes many predators from getting close to the nest.
These other foundresses also forage for food, provisioning the larvae with chunks of caterpillar, as well as defend the nest. However, unlike in other eusocial Hymenoptera, these wasps tend to act as independent agents. While the queen is at the top of the dominance hierarchy, the other wasps may lay eggs and forage for themselves as they see fit. In cases where queens or foundresses evict other females, the aggregations begin to dissolve. At nighttime and in the early morning, the entire female population of a P. annularis colony is located on the nest. After the first brood pupate by spinning a cocoons that encloses the larval cell, they emerge as adults. The co-foundresses then remain on the nest with the dominant foundress until dying off.
The first brood of offspring in the spring is primarily composed of non-reproductive female workers, with few if any males. Later generations beginning in the summer produce female reproductives, depending on ambient conditions, and then male reproductives. A few days after adult males emerge, they leave their natal nest to mate. Although the probability is very low, a worker herself can eventually mate and assume the role of queen in the event that all foundresses of the nest die or leave permanently. Between mid-July and mid-October, P. annularis nests arrest their brood production.
Beginning during early to mid autumn as the temperature drops below about 5 °C and the workers die off, reproductive females prepare for winter by collecting and storing nectar in a highly concentrated form within open cells of the natal nest that eventually becomes a sort of honey. By the winter, these reproductive females abandon the nest to hibernate, residing in shelters known as hibernacula, which include cracks within cliff walls. During cold conditions as compared to normal foraging temperatures, both sexes have increased levels of trehalose, and females also have increased levels of glucose and fructose. Foundresses have higher storage capability for glycogen than workers, allowing them to better survive low temperatures that causes workers to die. Males, which often higher levels of glucose, fructose, and trehalose than foundresses, are able to continue mating into autumn or winter. P. annularis cannot tolerate frost, though it has been shown to be able to survive at temperatures below the minimum temperature in the area in which it resides. On warmer days of the winter, they fly back to the natal nest to feed on their stored honey, increasing their ability to survive the cold of winter, as well as interact with their nest-mates. In early January, reproductive males and females commence mating at the hibernacula. In the following spring, foundresses are retain association with their nestmates from the natal nest of the previous autumn and begin the colony cycle anew.
Variations in the colony cycle The colony cycle of P. annularis exhibits slight variations from year to year based on environmental conditions. One factor is the ability of females to switch castes. After the early brood of workers emerge from the eggs, the nest usually the original reproductive foundress before more eggs can be laid at the end of the season. In this case, a worker with fully developed ovaries takes over the nest and becomes a gyne. However, this also results in an earlier arrest in rearing brood, which may be due to a decrease in relatedness between the new reproductive and the nascent females or due to internal conflict on the nest. Additionally, if resources decrease, as during a drought, brood rearing ends sooner than in more prosperous years, and females choose to become gynes as opposed to workers.