German wasp | |
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Near Swifts Creek, Victoria | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Vespidae |
Genus: | Vespula |
Species: | V. germanica |
Binomial name | |
Vespula germanica (Fabricius, 1793) | |
Distribution map of European wasp blue : native, red : introduced |
Vespula germanica, known colloquially as the European wasp, German wasp, or German yellowjacket, is a species of wasp found in much of the Northern Hemisphere, native to Europe, Northern Africa, and temperate Asia. It has spread and become well-established in many other places, including North America, South America (Argentina and Chile), Australia, South Africa, and New Zealand. German wasps are part of the family Vespidae and are sometimes mistakenly referred to as paper wasps because they build grey paper nests, although strictly speaking, paper wasps are part of the subfamily Polistinae. In North America, they are also known as yellowjackets.
Vespula germanica belongs to the genus Vespula , which includes various species of social wasps that are found throughout the Northern Hemisphere. In North America, these wasps are most commonly known as yellowjackets, but this name also applies to species within the sister genus Dolichovespula . Members of Vespula are often confused with other genera, especially the paper wasp Polistes dominula . Colonies of V. germanica share many characteristics with those of V. vulgaris (common wasp) and V. pensylvanica (western yellowjacket), so they are very often studied together. [1]
The German wasp is about 13 mm (0.5 in) long, has a mass of 74.1 ± 9.6 mg, [2] and has typical wasp colours of black and yellow. It is very similar to the common wasp (V. vulgaris), but unlike the common wasp, has three tiny black dots on the clypeus. To further complicate the issue this only applies to workers. To help with identification, a good practice to observe is to first categorize the wasp as worker, queen, or male before identifying it as V. vulgaris or V. germanica. Gastral pattern (the black dots or marks on the abdomen) are highly variable and not good characteristics to use in identifying. However, the identification of a wasp as V. vulgaris may be difficult because the normally unbroken black mark on its clypeus can sometimes appear broken (particularly in males) making it look extremely similar to V. germanica.[ citation needed ]
V. germanica originated in Europe, Asia, and North Africa and can now be found in sections of every continent but Antarctica. It has established populations in North America, South America, South Africa, New Zealand, and Australia. The species has been described as an invasive species. [3] German yellowjackets are known to be especially successful and destructive invaders of new territories. These wasps are polyphagous predators which feed on native arthropods, and because they are able to outdo many other animals for food, they have caused considerable harm to the indigenous wildlife of areas which they have invaded. For a given year, V. germanica disperses at distances of no more than 1000 m, so that their rapid dispersal is likely to be aided by accidental human transport of hibernating queens. This normally leads to a bottleneck effect during the establishment of new populations, which explains the significant genetic differentiation often found among geographically distant populations. [4]
The nest is made from chewed plant fibres, mixed with saliva. The majority of nests are found in the soil below ground. A significant portion of nests are found in artificial structures such as attics, and a small portion are found above ground. [5]
A single queen initiates a nest in the spring by constructing an embryonic nest, which contains a series of hexagonal cells. These cells are used to house one wasp through the immature stages of life: egg, larval instar, and pupa. The colony grows rapidly during the summer with a huge increase in worker numbers and nest size. By the end of summer, the rate of growth slows considerably and more males are produced than workers, and the focus is shifted from building small cells to building cells that are 30-40 percent larger. These new cells house the new queens and males. In the fall, the new queens begin hibernation, while the old queens die off and the colony collapses. In some cases, the nests may survive through the winter and reach the next season. If this occurs, the nest will become polygynous and reach a much larger size than in the previous year. [5]
V. germanica nests are strongly affected by climate. Average colonies in Australia contain over 9500 small workers and 3600 large queen and male cells. By the end of May, colonies in Australia have 15,000 wasps emerging from small cells and 2500 wasps emerging from the large cells. [5] By comparison, nests in the British Isles only have 6100–6500 small cells and 1500 large cells on average, in roughly eight combs. [6] Additionally, a significant number of nests in Australia are able to survive the winter, whereas in England none of the nests survive. This demonstrates how V. germanica nests can reach a substantial size in appropriate climate conditions. [5]
High variation in the sequence and diversity of tasks performed by V. germanica workers suggests limited temporal polyethism exists within the species. Temporal polyethism is a mechanism in which workers specialize on tasks in a sequential order throughout their lives, instead of performing numerous tasks concurrently. The typical order of tasks in V. germanica is nest work, pulp foraging, carbohydrate foraging and protein foraging. Approximately 61 percent of the wasps observed perform more than two of these tasks during their lifetimes. Additionally, about 40 percent of the wasps specialize on only one task per day, but these individuals varied with respect to age and sequence of task performance. The schedule of temporal polyethism found in V. germanica is highly accelerated when compared to other Hymenoptera, which is likely related to worker lifespan. Vespula workers may not live long enough to benefit from a strict system of worker specialization, in which workers repeatedly perform one task. [7]
Vespula germanica queens are typically polyandrous. The queens mate with a moderate number of males, usually between one and seven, with no optimal number of mates. In addition, mating events are independent of each other, which discredits the hypothesis that queens terminate mating behavior after mating with a male that possesses an optimal set of attributes. [8]
V. germanica workers are unable to mate and so incapable of producing diploid offspring. In some nests, however, the workers produce haploid male offspring from unfertilized eggs. Worker reproduction has been documented in other Vespula wasp colonies, but usually only after the death of the queen. However, workers of V. germanica have been found reproducing in the presence of a queen. [8]
Vespula germanica workers are known to be opportunistic predators and scavengers. They are efficient at hunting for small, live food sources and at collecting from large stationary sources. [9] It is believed that the flexibility in V. germanica's foraging behavior is a key factor in their ability to rapidly colonize new areas in a variety of ecological environments. As scavengers, V. germanica are forced to make numerous trips between the location of the food source and the nest, where the larvae are kept and fed. [10] This calls for V. germanica foragers to be adept at relocating earlier food sources.
The ability to relocate previously discovered food sources is only one example of the diverse cognitive mechanisms at play within V. germanica's behaviors. V. germanica foragers continue to visit a feeder after food removal, but are able to rapidly remove associations that no longer provide a reward. The amount of time that the foragers continue to search these sites depends on the number of times they had visited it in the past. The choices made by V. germanica take into account both current and past experiences. These abilities imply that these wasps have important learning and memory capacities which enable them to memorize various resource characteristics, including the route to resources, as well as specific spatial location with respect to local landmarks. In addition, V. germanica wasps have been shown to have sensorimotor learning capacities which allow them to associate visual stimuli with certain motor responses. [10] This reported high cognitive plasticity enables V. germanica wasps to inhabit a variety of regions. Its flexibility in nesting and diet habits in conjunction with its foraging capabilities may help explain the success with which V. germanica has invaded so many different ecological areas. [9]
V. germanica queens are typically polyandrous. [11] Because the queen mates with multiple males, the workers are more closely related to the queen's sons than to sons of other workers. [8] These asymmetries in relatedness are believed to be a factor leading to worker policing within colonies. [11]
Male reproductive skew within V. germanica indicates that males do not contribute equally to the production of offspring when compared to females. The level of skew observed was higher among males in nests with queens that mated with multiple males. Reproductive skew may be linked to patterns of sex allocation, but sex ratio data for Vespula colonies suggest that a split-sex ratio is not produced. This contradicts the theory that the reproductive skew seen in V. germanica is part of an evolutionary strategy of males due to asymmetries in relatedness. [8]
Worker policing is selected for when it benefits the colony. The benefits are gained through various measures, such as increasing colony efficiency and establishing a female-based sex-allocation ratio. Worker policing is especially common in colonies where queens mate with multiple males. Thus on average, the workers are more closely related to sons of the queen than to those of other workers. In the past, V. germanica was thought to be an exception to the general pattern that high mating frequency led to low levels of worker reproduction. However, recent studies indicate that while worker reproduction occurs at a considerable rate, worker policing keeps these worker-laid eggs from reaching adulthood. This is demonstrated by a study carried out in Belgium, showing that while an estimated 58.4 percent of male eggs were laid by workers, only 0.44 percent of adult males were workers' sons. The numbers indicate the efficiency with which worker policing is carried out. Policing by aggression, which prevents workers from laying eggs in the first place, leads to increases in colony productivity, while policing by eating the eggs of workers is more likely to result in sex-ratio benefits. [11]
V. germanica wasps have a diverse diet. They are known to eat carrion, live arthropods (including spiders [12] ), fruit, [10] honeydew, and processed human food and garbage. [13] They are opportunistic scavengers and hunters able to obtain food from a variety of different sources. [9] For example, many Vespula species have been observed feeding on dead honey bees ( Apis mellifera ) found outside the beehive entrance in the late summer. [14] This flexibility in diet is beneficial, because V. germanica must often compete for resources with native biota in areas it invades. [15]
Female bee moths ( Aphomia sociella ) have been known to lay eggs in the nests of V. germanica. Hatched larvae will then feed on the eggs, larvae, and pupae left unprotected by the wasp, sometimes destroying large parts of the nest as they tunnel throughout looking for food. [16]
The species is considered a pest in most areas outside its native range, although its long residency in North America means it is not treated with any level of urgency there, unlike in areas such as South America, where the introduction is more recent and the impacts more dramatic. [17]
Along with the closely related common wasp (Vespula vulgaris) and three species of Polistes paper wasps, the German wasp is considered a pest in New Zealand. It was probably introduced in the late 19th century, but did not appear in large numbers until around 1940. [18] Wasp numbers reach their greatest densities in beech forest of the South Island, due to the abundant honeydew produced by the beech-scale insect there. This has a serious effect on forest ecology, as less honeydew remains available for native birds. However, German wasps were quickly succeeded in much of the South Island and its beech forests by Vespula vulgaris accidentally introduced in the 1970s. [19] [20]
The Vespidae are a large, diverse, cosmopolitan family of wasps, including nearly all the known eusocial wasps and many solitary wasps. Each social wasp colony includes a queen and a number of female workers with varying degrees of sterility relative to the queen. In temperate social species, colonies usually last only one year, dying at the onset of winter. New queens and males (drones) are produced towards the end of the summer, and after mating, the queens hibernate over winter in cracks or other sheltered locations. The nests of most species are constructed out of mud, but polistines and vespines use plant fibers, chewed to form a sort of paper. Many species are pollen vectors contributing to the pollination of several plants, being potential or even effective pollinators, while others are notable predators of pest insect species, and a few species are invasive pests.
Yellowjacket or yellow jacket is the common name in North America for predatory social wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as "wasps" in other English-speaking countries. Most of these are black and yellow like the eastern yellowjacket and the aerial yellowjacket ; some are black and white like the bald-faced hornet. Some have an abdomen with a red background color instead of black. They can be identified by their distinctive markings, their occurrence only in colonies, and a characteristic, rapid, side-to-side flight pattern prior to landing. All females are capable of stinging. Yellowjackets are important predators of pest insects.
Dolichovespula maculata is a species of wasp in the genus Dolichovespula and a member of the eusocial, cosmopolitan family Vespidae. It is taxonomically an aerial yellowjacket but is known by many colloquial names, primarily bald-faced hornet, but also including bald-faced aerial yellowjacket, bald-faced wasp, bald hornet, white-faced hornet, blackjacket, white-tailed hornet, spruce wasp, and bull wasp. Technically a species of yellowjacket wasp, it is not one of the true hornets, which are in the genus Vespa. Colonies contain 400 to 700 workers, the largest recorded colony size in its genus, Dolichovespula. It builds a characteristic large hanging paper nest up to 58 cm (23 in) in length. Workers aggressively defend their nest by repeatedly stinging invaders.
Vespula vulgaris, known as the common wasp, is a species found in regions that include the United Kingdom, Ireland, Germany, India, China, New Zealand and Australia. It is sometimes known in English as the European wasp, but the same name is used for the species Vespula germanica or German wasp. In 2010, the ostensible Vespula vulgaris wasps in North America were found to be a different species, Vespula alascensis.
The European paper wasp is one of the most common and well-known species of social wasps in the genus Polistes. Its diet is more diverse than those of most Polistes species—many genera of insects versus mainly caterpillars in other Polistes—giving it superior survivability compared to other wasp species during a shortage of resources.
Polistes humilis, known as the Australian paper wasp, is a species of wasp in the family Vespidae that is found throughout Australia and which has been introduced to northern New Zealand. These paper wasps can be identified by their long thin legs and banded yellow and black coloring. They have been known to re-utilize old nests. While the species does not exhibit morphological class differences, there are distinct behavioral differences between queens and workers. In addition, the species is eusocial and benefits from relatedness between individuals. They are known for delivering a painful sting, especially when their nest is disturbed, a behavior that has been developed as a nest defense mechanism. While wasps are often viewed negatively, they play an important pollination role for many plants.
Ropalidia marginata is an Old World species of paper wasp. It is primitively eusocial, not showing the same bias in brood care seen in other social insects with greater asymmetry in relatedness. The species employs a variety of colony founding strategies, sometimes with single founders and sometimes in groups of variable number. The queen does not use physical dominance to control workers; there is evidence of pheromones being used to suppress other female workers from overtaking queenship.
Vespula pensylvanica, the western yellowjacket, is a Nearctic species of wasp in the genus Vespula. It is native to regions of North America, largely in areas with northern temperate climates. Its reproductive behavior is constrained by cold weather, which successfully reduces the number of western yellowjackets in cold months. However, in the absence of cold weather, this wasp's population can explode. The western yellowjacket has become particularly invasive in the Hawaiian Islands, resulting in their label as a major pest.
The eastern yellow jacket or eastern yellowjacket is a wasp found in eastern North America. Although most of their nests are subterranean, they are often considered a pest due to their nesting in recreational areas and buildings. This yellow jacket is a social insect, living in colonies of hundreds to thousands of individuals. Along with their subfamily, Vespinae, this species demonstrates supportive parental care for offspring, separation of reproductive and sterile castes, and overlapping generations. They aggressively defend their hives from threats and are known to inflict painful stings.
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. 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.
Dolichovespula saxonica, also known as the Saxon wasp, is a common social wasp found in the Palearctic region, specifically in large parts of Europe and in northern and central Asia. Although originally from continental Europe, D. saxonica has since colonised Britain, mainly in the south and east, but has been recorded as far north as East Lothian, Scotland. Most of their nests are above ground in trees and bushes, but they can also be found in buildings. Due to the proliferation of nests in urban areas and near residential homes, D. saxonica can be a pest for people. As a result, many human interventions are in place to remove Saxon nests. D. saxonica has been found to use chemical signaling in a lot of behaviours, such as alarm calls, fertility cues, and chemical trails.
The tree wasp is a species of eusocial wasp in the family Vespidae, found in the temperate regions of Eurasia, particularly in western Europe. Despite being called the tree wasp, it builds both aerial and underground paper nests, and can be found in rural and urban habitats. D. sylvestris is a medium-sized wasp that has yellow and black stripes and a black dot in the center of its clypeus. It is most common to see this wasp between May and September during its 3.5 month colony cycle.
Vespula rufa, commonly known as the red wasp, is a social wasp species belonging to the genus Vespula. It is found in northern and central Europe and parts of Asia. Vespula rufa is characterised by red-brown markings and body segmentation, with the appearance varying amongst the different roles of individuals in the species. These wasps build small nests in dry banks underground that are not far below the surface. The colony cycle begins in the fall. Vespula rufa feed on live insects. One interesting fact about Vespula rufa is that the queen policing occurs in the species, and that worker policing occurs at much lower rates than other species in the genus Vespula. There are predators and parasites of the species. The species goes through a series of events before leaving the nest.
Vespula acadica, also known as the Forest Yellowjacket, is a North American species of eusocial wasp which is part of the "rufa" group within the genus Vespula. It is a black and yellow wasp that is found in arboreal areas and builds its nests most often in decaying vegetation like logs, but has occasionally been found to build aerial nests. Due to its preference for forests V. acadica does not normally come into contact with humans; however, when colonies are disturbed, workers of this yellowjacket may be quite aggressive and persistent and sting repeatedly.
Vespula squamosa, or the southern yellowjacket, is a social wasp. This species can be identified by its distinctive black and yellow patterning and orange queen. This species is typically found in eastern North America, and its territory extends as far south as Central America. Within these territories, they create enormous, multiple-comb nests. The colonies may be either annual or perennial depending on the climate, and in many perennial nests, polygyny takes place. In addition, this species uses pheromones both as a sexual attractant and an alarm signal. This species feeds on insects and animal carcasses; it does not produce honey. V. squamosa, a social insect, has developed a parasitic relationship with the species V. vidua and V. maculifrons. Due to their painful, venomous stings, the species is considered a pest.
Dolichovespula arenaria, also known as the common aerial yellowjacket, sandhills hornet, and common yellow hornet, is a species of wasp within the genus Dolichovespula widely distributed in the North American continent.
Polistes nimpha is a eusocial paper wasp found all over Europe, with particular sightings in Turkey, Finland, Estonia, and Latvia. It is also found in northern Africa, Pakistan, Iran, India, Kazakhstan, Mongolia, and China. The climate in these areas is relatively cold and snowy in the winter, while summers are usually hot and dry, with steppe vegetation. Polistes nimpha colonies are relatively small and easily manipulated.
Vespula atropilosa, also known as the prairie yellowjacket, is a black and yellow social wasp that forms annual colonies. Vespula atropilosa was formerly a member of the Vespa family. Males have either xanthic (yellow) or melanic (black) abdominal coloring. The prairie yellowjacket can be found in the Western and Midwestern United States as well as parts of southern Canada. It builds its nests underground and prefers large open areas such as pastures and golf courses. Vespula atropilosa colonies are founded by a queen in the spring and grow most during mid-summer. It preys on other insects such as flies and grasshoppers but is not a scavenger like other wasps. Queens mate with multiple males, and males will fight each other for matings. V. atropilosa is a social wasp that practices altruism. Prairie yellowjackets are not considered pests but are commonly found in backyards in the Pacific Northwest. This species derives its common name from the prairies and grasslands where it can be found.
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.
Vespula infernalis is an obligate parasitic wasp, parasitizing the nests of other species in the genus Vespula. Its common host species is V. acadica in North America. It is sometimes called the cuckoo yellowjacket wasp due to its inquiline lifestyle. They differ from other parasitic wasps in their intensely aggressive behaviour during invasion and occupation of the host colony. Several morphological adaptations such as bigger body parts and highly curved stingers are present in these wasps to aid their aggressive parasitic behaviour.