Polybioides raphigastra | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Vespidae |
Subfamily: | Polistinae |
Genus: | Polybioides |
Species: | P. raphigastra |
Binomial name | |
Polybioides raphigastra (Saussure, 1854) | |
Synonyms | |
Polybia sumatrensis |
Polybioides raphigastra is a species of social wasp found in the forests of South East Asia and Indonesia. It has recently been placed in the tribe Ropalidiini. This species is known for the downward-spiraling shape of their nests, and for having colony sizes exceeding ten thousand members.
The Swiss entomologist Henri Louis Frédéric de Saussure described P. raphigastra in 1854. At the time, it was identified by the synonym Polybia sumatrensis de Saussure.
P. raphigastra is one of six known species that comprise the genus Polybioides. Four of these species live in South East Asia, Indonesia, and the Philippines, and the other two are located in equatorial Africa. [1] Polybioides were recently included in the tribe Ropalidiini, which, along with Polistini, Epiponini, and Mischocyttarini, make up the subfamily Polistinae. [2]
Other members of the genus include: Polybioides angustus , Polybioides gracilis , Polybioides melaina , Polybioides psecas , and Polybioides tabidus .
P. raphigastra bodies are composed of mostly dark areas, with lighter areas near the edge of segmented appendages. These dark areas are pale brown with light areas maintaining various shades of yellow. [3]
The species nests in closed cavities such as caves and hollow trees. [4] When nests are constructed within tree trunks, the trunks are often left entirely intact, with only small crevices giving access to the internal cavities that house the nest. In the trunk cavity, nests hang vertically with the envelope surrounding the nest directly attached to the inside of the cavity. Nests, often ovoidal in shape, may measure approximately 23 cm in length, with maximum diameters of 14.5 x 16 cm. [1] Nests may contain well over ten thousand cells. Nests are egg-shaped and formed of a single, helicoidal comb that winds upon itself eight or nine times in a fashion so that each whorl is partially enclosed by the following one. Nests are entirely composed of very short plant hairs bound together by differing levels of secretion. Nest color is brown to yellowish, and the envelope may be darker than the cells inside. The outer envelope displays crescent-like patterns of colors varying from white to reddish brown. [1] Each whorl on the nest is composed of two parts: a lower aspect constitutes the comb and an upper aspect that forms the envelope; leading to the number of layers of the envelope being roughly equivalent to the number of tiers of whorls. The curved structure, which curls spirally on itself in a series of layers, growing larger and larger may vaguely resemble the shell of a sea snail. Towards the center of each tier, the cells axes point downwards while near the edge of the envelope (the periphery) they are faced almost horizontal. The architecture of P. raphigastra nests appear to be unique among the Vespidae, though spiral combs may be found in other species of swarm-founding Ropalidiini and Epiponini. Additionally, its tendency to enwrap and protect previously built structures as it grows is similar to Agelaia areata.
P. raphigastra resides primarily in the forests of South East Asia and Indonesia. [1] However, the genus as a whole has a quite peculiar geographical distribution as it contains species residing in the Philippines and equatorial Africa. P. raphigastra constructs elaborate nests inside small cavities such as tree trunks. These nests are characterized by vertical combs surrounded by an envelope.
Due to the exclusively tropical distribution of these wasps, it is suspected that colony initiation occurs akin to most of the South-American Polistinae, in which colonies are founded by a group of individuals of which at least one is a fertilized female. [3] This type of colony foundation is also referred to as swarming. Founded colonies are pleiometrotic, meaning that there may be two or more egg-laying, fertilized females in the same nest.
When looking at the nest of P. raphigastra during the growing season, a large number of immature instars may be found throughout the nest. Eggs, larvae, and pupae are found in hexagonal cells at various distances from the start of the comb and there is evidence that cells are reused several times for the function of brood rearing. It has been shown that the majority of cells are bottomless with a maximum length of 0.7 cm, with only the most recently built cells having bottoms. A habit they have in common with all of the Ropalidiini tribe is that bottoms of cells are cut off very early by adults, leaving full grown larvae to lie in the cell with their abdomens protruding out of the cell. Pupae benefit from a two-domed cocoon that is reinforced with similar material used for nest building. The posterior dome has an opening that allows for the extraction of the peritrophic sac, which is where larval faeces accumulate. These findings indicate a degree of parental care that includes the elimination of excretions. Additionally, eggs are attached laterally onto the wall of cells that are open on both sides.
One of the most important activities that must be coordinated in a colony of social insects is the response to danger. [5] These defensive responses may vary greatly, ranging from mass attacks to full-scale retreats back into the nest. In most species, these responses have shown to be regulated by pheromones produced by various glands. Field experiments in which crushed venom glands and stings of P. raphigastra workers were placed in close proximity to the opening of a P. raphigastra nest showed that the number of wasps leaving the nest entrance was significantly higher when these glands were presented relative to the control (crushed thoraces). Similarly, when the crushed glands and control were presented simultaneously near the entrance to the nest, workers were not only more attracted to the glands but in many cases attempted to string the area around them. It is known that this same behavior may be elicited in other social wasp species as well.
There are many mimics of P. raphigastra. Stratiomyid flies may successfully fly along with members of Polybioides. There are also mantispids with the same general body constitution and coloration as P. raphigastra.Polistes meadeanus, also known as Polybia andrei and Polybio shelfordi, imitates Polybioides so effectively that even experienced hymenopterists may fail to recognize they are of the genus Polistes .
It has been shown that in some nests of P. raphigastra, only 25% of the specimens may be males. No obvious morphological distinctions may be made between queens and workers, though it is simple to group males apart from females. However, within those grouped as females there is considerable variation in size, indicating that there may be a distinct queen and worker caste.
It is well known that members of the species respond aggressively to vertebrate animals, with workers often attacking unprovoked at great distances away from the nest, and continuing to pursue their victims for several minutes. [5] [6] Further, these individual workers may effectively tag an enemy and elicit a colony-wide threat response via pheremones located in their venom glands. It is this aggressive response, shared by all members of the genus Polybioides, that was utilized by the Viet Cong during the Vietnam War. Guerrilla fighters would employ swarms of bees in booby traps intentioned to quick-release these territorial wasps directly nearby enemy troops. The simultaneous aggressive response would leave victims with up to 200 stings, virtually ensuring mortality.
The occurrences of sting autotomy in P. raphigastra is the first reported for a Ropalidiine species. Autotomy is a common phenomenon in bees and has also been found to occur in several wasp species of the tribes Epiponini and Polistini. [5] Autotomy is the ability of an organism to shed or discard one of its own appendages. In P. raphigastra, this ability has shown to be a special defensive mechanism against vertebrate predators. [7]
It is hypothesized that autotomy in P. raphigastra occurs as a result of the shape and size of their sting barbs. Stings resemble two sharp rods clasped together and tapered off in width closer to the end known as lancets. The external surface of the lancets possess large, well developed barbs through the length of the sting that are arranged in a helicoidal distribution. The inner passage between the two lancets is the canal through which venom travels as it exits the sting. In P. raphigastra, this otherwise smooth median margin contains a tooth-like structure and a semicircular incisure. It is proposed that these artifacts, along with the arrangement of the barbs, serve to impede the extraction of stings from the victim. [5]
Venom sacs contain both saturated and unsaturated linear hydrocarbons of a chain length between 11 and 18 carbon atoms. The major components are pentadecane and pentadecene. P. raphigastra venom is also known to contain phenol, benzaldehyde, phenylacetaldehyde, naphthalene, indene, limonene and decanal. [5] Additionally, several compounds that have been identified in their venom function as alarm pheromones in other species of social insect.
Paper wasps are vespid wasps that gather fibers from dead wood and plant stems, which they mix with saliva, and use to construct nests made of gray or brown papery material. Some types of paper wasps are also sometimes called umbrella wasps, due to the distinctive design of their nests.
The Polistinae is a subfamily of eusocial wasps belonging to the family Vespidae. They are closely related to the more familiar wasps and true hornets of the subfamily Vespinae, containing four tribes. With about 1,100 species total, it is the second-most diverse subfamily within the Vespidae, and while most species are tropical or subtropical, they include some of the most frequently encountered large wasps in temperate regions.
Synoeca is a genus of eusocial paper wasps found in the tropical forests of the Americas. Commonly known as warrior wasps or drumming wasps, they are known for their aggressive behavior, a threat display consisting of multiple insects guarding a nest beating their wings in a synchronized fashion, and an extremely painful sting. The sting is barbed and if used often kills the wasp, which may be the reason why such a striking defensive display is used. This display escalates from drumming inside the nest to hundreds of wasps moving on to the envelope of the nest and of continuing to drum and only if this does not deter the threat do the wasps begin to sting.
Polybia occidentalis, commonly known as camoati, is a swarm-founding advanced eusocial wasp. Swarm-founding means that a swarm of these wasps find a nesting site and build the nest together. This species can be found in Central and South America. P. occidentalis preys on nectar, insects, and carbohydrate sources, while birds and ants prey on and parasitize them. P. occidentalis workers bite each other to communicate the time to start working.
Agelaia vicina is a species of wasp in the genus Agelaia. They are neotropical social wasps known to have the largest colony sizes and nest sizes among social wasps, with some colonies exceeding over one million individuals. They are predators of land arthropods, consuming both insects and spiders alike. Recent sperm morphology studies have shown that although Vespidae belong to the superfamily Vespoidea, A. vicina may be more phylogenetically related to Apoidea.
Polistes canadensis is a species of red paper wasp found in the Neotropical realm. It is a primitively eusocial wasp as a member of the subfamily Polistinae. A largely predatory species, it hunts for caterpillar meat to supply its colony, often supplementing its developing larvae with nectar. The most widely distributed American species of the genus Polistes, it colonises multiple combs, which it rears year-round.
Synoeca cyanea, commonly known as the marimbondo-tatu in Brazil, is a swarm-founding eusocial wasp. Native to Brazil and Argentina, S. cyanea is one of the largest and most aggressive species of social wasps and is feared in many rural areas. It begins its colony cycle in the early spring and continues until nest abandonment. Throughout its life, S. cyanea forage sugary substances and animal carcasses for food and wood pulp for its nest. S. cyanea is also known for its strong venom, which is enough to cause haemolytic activity.
Agelaia pallipes is a species of social paper wasp found from Costa Rica to Argentina and Paraguay. A. pallipes is ground-nesting and is one of the most aggressive wasps in South America. This species is a predator of other insects, including flies, moths, and ground crickets, as well as baby birds.
Protonectarina sylveirae, commonly referred to as the Brazilian wasp, is a neotropical swarm-founding wasp species that ranges widely across South America. This species relies heavily on the consumption of animal protein rather than nectar. P. sylveirae preys heavily on agricultural pests to coffee crops, keeping pest populations low.
Leipomeles dorsata is a neotropical paper wasp that is found across Central America and northern South America. It is a eusocial wasp with little differentiation between reproducing and non-reproducing females. In fact, workers can become temporary reproductives if the main reproductives are killed, allowing reproduction to continue until the main reproductive population recovers. The colony cycles through different ratios of main reproductive females and subordinate reproductive females, starting with few or no primary reproducing females, and increasing until there are only main reproductives.
The African swarm-founding wasp, Polybioides tabidus, is a social paper wasp from the order Hymenoptera that is typically found in Central Africa. This wasp is unique in that it exhibits cyclical oligogyny, meaning queen number varies with colony cycle. After several generations of production of workers and future queens, a subset of many workers and queens leave the original colony to begin a new one. The new colony does not produce new queens until current queens from the old colony have died. P. tabidus has been observed to display both predator and scavenger behavior, depending on the food sources available.
Protopolybia exigua is a species of vespid wasp found in South America and Southern Brazil. These neotropical wasps, of the tribe Epiponini, form large colonies with multiple queens per colony. P. exigua are small wasps that find nourishment from nectar and prey on arthropods. Their nests are disc-shaped and hang from the undersides of leaves and tree branches. This particular species of wasp can be hard to study because they frequently abandon their nests. P. exigua continuously seek refuge from phorid fly attacks and thus often flee infested nests to build new ones. The wasps' most common predators are ants and the parasitoid phorid flies from the Phoridae family.
Polybia sericea is a social, tropical wasp of the family Vespidae that can be found in South America. It founds its colonies by swarming migrations, and feeds on nectar and arthropods.
Ropalidia romandi, also known as the yellow brown paper wasp or the yellow paper wasp. is a species of paper wasp found in Northern and Eastern Australia. R. romandi is a swarm-founding wasp, and manages perennial nests. Its nests are known as 'paper bag nests' and have different architectural structures, depending on the substrates from which they are built. The specific name honors Gustave, baron de Romand, a prominent French political figure and amateur entomologist.
Synoeca surinama is a Neotropical swarm-founding wasp of the tribe Epiponini. It is known for its metallic blue and black appearance and painful sting. S. surinama builds nests on tree trunks and can be found in tropical climates of South America. When preparing to swarm, there are a number of pre-swarming behaviors that members of S. surinama colonies partake in, such as buzzing runs and occasional brood cannibalism. In S. surinama, social environmental conditions determine the caste ranks of individuals in the developing brood. Unlike less primitive Hymenoptera species, S. surinama display little morphological variation between egg laying queens and workers. S. surinama wasps visit flowering plants and are considered pollinators. When these wasps sting, the stinger is left in the victim and the wasp ultimately dies.
Parachartergus fraternus is a neotropical, swarm founding, polistine wasp species that is distributed throughout Central and South America. They live in nests in second growth tropical dry forests, near pasture fields, roadside areas, and urban areas as well. These wasps eat insects, such as caterpillars of Lepidoptera. They also drink nectar, honeydew, and water. The workers capture their prey during foraging. They also use venom to paralyze their prey in order to consume it later. P. fraternus wasps are not very aggressive and they do not attack when the nest is approached.
Synoeca septentrionalis is one of five species of wasps in the genus Synoeca. It is a swarm-founding wasp that is also eusocial, exhibiting complicated nest structure and defense mechanisms and a colony cycle including a pre-emergence phase and a post-emergence phase. It is typically found in areas from Central to South America. This wasp is one of the larger species of paper wasps and exhibits multiple morphological adaptations as a result of this. S. septentrionalis is known for possessing a very painful sting.
Agelaia multipicta is a swarm-founding, highly eusocial wasp that lives in Mexico, Argentina, Trinidad and southern Brazil. It nests in natural cavities such as hollow trees and aggressively defends the nest from ants, who are brood predators. The workers and queens are morphologically distinguished by ovarian development as well as external features such as a larger petiole and gaster in the queen. Like other carrion-eating (necrophagous) wasp species, A. multipicta plays a scavenging role in the ecosystem. Agelaia multipicta was described by the Irish entomologist Alexander Henry Haliday in 1836.
Protopolybia chartergoides, also known as Pseudochartergus chartergoides, is a species of wasp within the genus Protopolybia. It is a social wasp found in southern Central America and northern South America.
Polybia paulista is a species of eusocial wasp occurring in Brazil, Paraguay, and Argentina.