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{{Short description|Species of wasp}}
{{italic title}}
{{Italic title}}
{{Taxobox
{{Speciesbox
| image= Ropalidia romandi 7283.jpg
| image_caption = Burdekin River, Queensland
| name = Yellow Paper Wasp
| name = Yellow Paper Wasp
| taxon = Ropalidia romandi
| regnum = [[Animal]]ia
| display_parents = 3
| phylum = [[Arthropod]]a
| classis = [[Insect]]a
| authority = ([[Le Guillou]], 1841)}}
| ordo = [[Hymenoptera]]
| familia = [[Vespidae]]
| subfamilia = [[Polistinae]]
| genus = ''[[Ropalidia]]''
| species = '''''R. romandi'''''
| binomial = ''Ropalidia romandi''
| binomial_authority = ([[Le Guillou]], 1841)}}


'''''Ropalidia romandi''''', also known as the '''yellow brown paper wasp'''<ref name=":0">{{Cite web|url = http://www.brisbaneinsects.com/brisbane_vespoidwasps/YellowPaperWasp.htm|title = Brisbane Insects|date = |accessdate = October 13, 2014|website = |publisher = |last = |first = }}</ref> or the '''yellow paper wasp.'''<ref name=":4">{{Cite web|url = http://gvcocks.homeip.net/hymenoptera/Vespidae/ropalidia_romandi.htm|title = Insects of Townsville|date = |accessdate = October 13, 2014|website = |publisher = |last = |first = }}</ref> is a species of [[paper wasp]] found in Northern and Eastern Australia. ''R. romandi ''is a swarm-founding wasp, and manages perennial nests.<ref name=":5">{{Cite journal|url = |title = Colony cycle of an Australian swarm-founding paper wasp,Ropalidia romandi (Hymenoptera: Vespidae)|last = Kojima|first = J.|date = 1996|journal = Insectes Sociaux|accessdate = |doi = 10.1007/BF01258413|pmid = |issue = 4|volume = 43 |pages=411–420}}</ref> Its nests are known as 'paper bag nests'<ref name=":9" /> and have different architectural structures, depending on the substrates from which they are built.<ref name=":2" /> The specific name honors [[Gustave de Romand|Gustave, baron de Romand]], a prominent French political figure and amateur entomologist.
'''''Ropalidia romandi''''', also known as the '''yellow brown paper wasp'''<ref name=":0">{{Cite web|url = http://www.brisbaneinsects.com/brisbane_vespoidwasps/YellowPaperWasp.htm|title = Brisbane Insects|access-date = October 13, 2014}}</ref> or the '''yellow paper wasp.'''<ref name=":4">{{Cite web|url = http://gvcocks.homeip.net/hymenoptera/Vespidae/ropalidia_romandi.htm|title = Insects of Townsville|access-date = October 13, 2014}}</ref> is a species of [[paper wasp]] found in Northern and Eastern Australia. ''R. romandi ''is a swarm-founding wasp, and manages perennial nests.<ref name=":5">{{Cite journal|title = Colony cycle of an Australian swarm-founding paper wasp, ''Ropalidia romandi'' (Hymenoptera: Vespidae)|last = Kojima|first = J.|date = 1996|journal = Insectes Sociaux|doi = 10.1007/BF01258413|issue = 4|volume = 43 |pages=411–420|s2cid = 35241710}}</ref> Its nests are known as 'paper bag nests'<ref name=":9" /> and have different architectural structures, depending on the substrates from which they are built.<ref name=":2" /> The specific name honors [[Gustave de Romand|Gustave, baron de Romand]], a prominent French political figure and amateur entomologist.


Because swarm-founding colonies can contain more than one egg-laying queen, they tend to challenge current [[kin selection]] theory. in that they do not meet [[William D. Hamilton]]’s rule of [[haplodiploid]] [[eusociality|eusocial]] Hymenoptera, in which all the sisters from a single mating of one queen with a parthenogenetically-produced male will share 75% of their genes.<ref name=":112">{{Cite journal|url = |title = Genetical and morphological colony structure of the Australian swarm-founding polistine wasp, Ropalidia romandi (Hymenoptera, Vespidae)|last = Tsuchida|first = K.|date = 2000|journal = Insectes Sociaux|accessdate = |doi = 10.1007/PL00001688|pmid = |last2 = et|first2 = al.|issue = 2|volume = 47 |pages=113–116}}
Because swarm-founding colonies can contain more than one egg-laying queen, they tend to challenge current [[kin selection]] theory. in that they do not meet [[William D. Hamilton]]’s rule of [[haplodiploid]] [[eusociality|eusocial]] Hymenoptera, in which all the sisters from a single mating of one queen with a parthenogenetically-produced male will share 75% of their genes.<ref name=":112">{{Cite journal|title = Genetical and morphological colony structure of the Australian swarm-founding polistine wasp, ''Ropalidia romandi'' (Hymenoptera, Vespidae)|last1 = Tsuchida|first1 = K.|date = 2000|journal = Insectes Sociaux|doi = 10.1007/PL00001688|last2 = et|first2 = al.|issue = 2|volume = 47 |pages=113–116|s2cid = 44016571}}
</ref> This wasp often has multiple [[strepsipteran]] endoparasites,<ref name=":1">{{Cite journal|url = |title = Multiple stylopisation of a paper wasp, Ropalidia romandi (Le Guillou) (Hymenoptera: Vespidae)|last = Wild|first = Clyde H.|date = 2010|journal = Australian Entomologist|accessdate = |doi = |pmid = |last2 = Hall|first2 = Casey R.|issue = 3|volume = 37}}</ref> and it delivers a very painful sting when threatened.<ref name=":0" /><ref name=":4" />
</ref> This wasp often has multiple [[strepsipteran]] endoparasites,<ref name=":1">{{Cite journal|title = Multiple stylopisation of a paper wasp, ''Ropalidia romandi'' (Le Guillou) (Hymenoptera: Vespidae)|last1 = Wild|first1 = Clyde H.|date = 2010|journal = Australian Entomologist|last2 = Hall|first2 = Casey R.|issue = 3|volume = 37}}</ref> and it delivers a very painful sting when threatened.<ref name=":0" /><ref name=":4" />


==Taxonomy and phylogeny==
==Taxonomy and phylogeny==
''Ropalidia romandi'', first named by Élie Jean François Le Guillou in 1841,<ref name=":1" /> is in the subfamily [[Polistinae]]. It contains two subspecies, ''R. romandi romandi'' (Le Guillou 1841) and'' R. romandi cabeti (''de Saussure 1853).<ref>{{Cite journal|url = |title = The Australian Social Wasps (Hymenoptera: Vespidae)|last = Richards|first = O. W.|date = 1978|journal = Australian Journal of Zoology: Supplementary Series|accessdate = |doi = |pmid = |volume = 61}}</ref> ''[[Ropalidia]]'' is the only genus in Polistinae that contains both independent-founding species, founded by only one or a few fertilized females, and swarm-founding species.<ref name=":2">{{Cite journal|url = |title = Nest Architecture of the Australian Paper Wasp Ropalidia Romandi Cabeti , With a Note on its Developmental Process (Hymenoptera: Vespidae)|last = Yamane|first = Soichi|date = 1994|journal = Psyche|accessdate = |doi =10.1155/1994/92839 |pmid = |last2 = Ito|first2 = Yosiaki|issue = 3–4|volume = 101 |pages=145–158}}</ref> Swarm-founding species within ''Ropalidia'' must thus have evolved independently from swarm-founding species found in other polistine genera.<ref name=":3">{{Cite journal|url = |title = Behavior during artificially induced swarm emigration in an old world polistine wasp, Ropalidia romandi (Hymenoptera: Vespidae)|last = Kojima|first = Jun-ichi|date = 1994|journal = Journal of Ethology|accessdate = |doi = 10.1007/BF02350073|pmid = |issue = 1|volume = 12 |pages=1–8}}</ref> This genus is distributed across [[Oceania]] and the Old World,<ref name=":2" /> and contains approximately 180 species.<ref name=":7">{{Cite journal|url = |title = Colony specific morphological caste differences in an Old World, swarm-founding polistine, ''Ropalidia romandi'' (Hymenoptera: Vespidae)|last = Fukuda|first = Hirokazu|date = 2003|journal = Entomological Science|accessdate = |doi = 10.1046/j.1343-8786.2003.00002.x|pmid = |last2 = et|first2 = al.|issue = 1|volume = 6 |pages=37–47}}</ref> It and the other three Old World polistine genera form a [[monophyletic]] group.<ref name=":7"/>
''Ropalidia romandi'', first named by Élie Jean François Le Guillou in 1841,<ref name=":1" /> is in the subfamily [[Polistinae]]. It contains two subspecies, ''R. romandi romandi'' (Le Guillou 1841) and'' R. romandi cabeti (''de Saussure 1853).<ref>{{Cite journal|title = The Australian Social Wasps (Hymenoptera: Vespidae)|last = Richards|first = O. W.|date = 1978|journal = Australian Journal of Zoology: Supplementary Series|volume = 61}}</ref> ''[[Ropalidia]]'' is the only genus in Polistinae that contains both independent-founding species, founded by only one or a few fertilized females, and swarm-founding species.<ref name=":2">{{Cite journal|title = Nest architecture of the Australian paper wasp ''Ropalidia romandi cabeti'', with a note on its developmental process (Hymenoptera: Vespidae)|last1 = Yamane|first1 = Soichi|date = 1994|journal = Psyche: A Journal of Entomology|doi =10.1155/1994/92839 |last2 = Ito|first2 = Yosiaki|issue = 3–4|volume = 101 |pages=145–158|doi-access = free}}</ref> Swarm-founding species within ''Ropalidia'' must thus have evolved independently from swarm-founding species found in other polistine genera.<ref name=":3">{{Cite journal|title = Behavior during artificially induced swarm emigration in an old world polistine wasp, ''Ropalidia romandi'' (Hymenoptera: Vespidae)|last = Kojima|first = Jun-ichi|date = 1994|journal = Journal of Ethology|doi = 10.1007/BF02350073|issue = 1|volume = 12 |pages=1–8|s2cid = 38229890}}</ref> This genus is distributed across [[Oceania]] and the Old World,<ref name=":2" /> and contains approximately 180 species.<ref name=":7">{{Cite journal|title = Colony specific morphological caste differences in an Old World, swarm-founding polistine, ''Ropalidia romandi'' (Hymenoptera: Vespidae)|last1 = Fukuda|first1 = Hirokazu|date = 2003|journal = Entomological Science|doi = 10.1046/j.1343-8786.2003.00002.x|last2 = et|first2 = al.|issue = 1|volume = 6 |pages=37–47|s2cid = 84695115}}</ref> It and the other three Old World polistine genera form a [[monophyletic]] group.<ref name=":7"/>


==Description==
==Description==
[[File:Wasp morphology.svg|thumb|Wasp morphology]]
[[File:Wasp morphology.svg|thumb|Wasp morphology]]


''Ropalidia romandi ''is unique for its overall yellow color, with dark brown markings on its thorax and abdomen.<ref name=":4" /><ref name=":6" /> Measuring around 12mm, ''R. romandi ''is considered small.<ref name=":0" /> The first segment of the abdomen in ''Ropalidia ''is narrower than the following segments. '' R. romandi''<nowiki/>'s front wings fold lengthwise when resting, which is a common characteristic of [[paper wasps]].<ref name=":8">{{Cite news|url = |title = Paper Wasps: Fact Sheet|last = Queensland Museum|first = |date = 2011|work = |accessdate = |publisher = Queensland Government}}</ref>
''Ropalidia romandi'' is unique for its overall yellow color, with dark brown markings on its thorax and abdomen.<ref name=":4" /><ref name=":6" /> Measuring around 12mm, ''R. romandi ''is considered small.<ref name=":0" /> The first segment of the abdomen in ''Ropalidia ''is narrower than the following segments. ''R. romandi''<nowiki/>'s front wings fold lengthwise when resting, which is a common characteristic of [[paper wasps]].<ref name=":8">{{Cite news|title = Paper Wasps: Fact Sheet|last = Queensland Museum|date = 2011|publisher = Queensland Government}}</ref>


Its nest is referred to as ‘paper bag nest’<ref name=":9">{{Cite journal|url = |title = Evidence for an Alarm Pheromone in Ropalidia romandi (Le Guillou) (Hymenoptera: Vespidae)|last = Kojima|first = J.|date = 1994|journal = Australian Journal of Entomology|accessdate = |doi = 10.1111/j.1440-6055.1994.tb00916.x|pmid = |volume = 33|issue = 1 |pages=45–47}}</ref> because it consists of a papery envelope covering several horizontal combs.<ref name=":2" /> Both the envelope and its contents are made of papery plant fibers glued together with saliva.<ref name=":2" /> The nest is either spherical or hemispherical in shape, can be up to one meter long, and is usually found in trees or eaves of buildings.<ref name=":8" /> <ref name=":2" />
Its nest is referred to as ‘paper bag nest’<ref name=":9">{{Cite journal|title = Evidence for an alarm pheromone in ''Ropalidia romandi'' (Le Guillou) (Hymenoptera: Vespidae)|last = Kojima|first = J.|date = 1994|journal = Australian Journal of Entomology|doi = 10.1111/j.1440-6055.1994.tb00916.x|volume = 33|issue = 1 |pages=45–47|doi-access = free}}</ref> because it consists of a papery envelope covering several horizontal combs.<ref name=":2" /> Both the envelope and its contents are made of papery plant fibers glued together with saliva.<ref name=":2" /> The nest is either spherical or hemispherical in shape, can be up to one meter long, and is usually found in trees or eaves of buildings.<ref name=":8" /><ref name=":2" />


==Distribution and habitat==
==Distribution and habitat==


In [[Australia]] ''R. romandi'' is found in Northern Territory and Queensland.<ref name=":5" /> It is one of the most common paper wasp species in Eastern Queensland.<ref name=":2" /> ''R. romandi'' lives in both tropical and temperate climates. However, their habitats are prone to cold winters, which results in seasonal colony activity.<ref name=":5" /> Nests can be found hanging from the underside of various tree branches and building eaves at anywhere from 2.5m to 30m above the ground.<ref name=":9" /><ref>{{Cite web|url = https://megoutlook.wordpress.com/tag/yellow-paper-wasp-ropalidia-romandi/|title = Smallest Wasp Builds Biggest Nest in Forest?|date = |accessdate = October 11, 2014|website = |publisher = |last = |first = }}</ref> They commonly attach their nests to [[Eucalypts]], which shed their bark frequently. When this occurs, the nests fall to the ground and are abandoned by the colony. Shortly after, a new nest is constructed.<ref name=":8" />
In [[Australia]] ''R. romandi'' is found in Northern Territory and Queensland.<ref name=":5" /> It is one of the most common paper wasp species in Eastern Queensland.<ref name=":2" /> ''R. romandi'' lives in both tropical and temperate climates. However, their habitats are prone to cold winters, which results in seasonal colony activity.<ref name=":5" /> Nests can be found hanging from the underside of various tree branches and building eaves at anywhere from 2.5m to 30m above the ground.<ref name=":9" /><ref>{{Cite web|url = https://megoutlook.wordpress.com/tag/yellow-paper-wasp-ropalidia-romandi/|title = Smallest Wasp Builds Biggest Nest in Forest?|access-date = October 11, 2014}}</ref> They commonly attach their nests to [[Eucalypts]], which shed their bark frequently. When this occurs, the nests fall to the ground and are abandoned by the colony. Shortly after, a new nest is constructed.<ref name=":8" />


==Colony cycle==
==Colony cycle==
''R. romandi ''is a swarm-founding species, which means its colonies are founded by a swarm of workers associating with queens (fertilized females).<ref name=":7" /> This is in contrast to what happens in independent-founding species, where the colony is founded by only one or a few fertilized females.<ref name=":7" /> ''R. romandi'' has been found to manage [[perennial]] nests that can last a few years.<ref name=":5" /> This means that the colony does not die off in the winter as they do in [[Year|annual]] colonies, but they instead survive the winter and manage the same nest the following season.<ref name=":5" /> Because of this, swarm-founding species normally have larger colonies with more queens than independent-founding species.<ref name=":9" /> Colony survival over the winter is thought to be possible because ''R. romandi ''practices seasonal colony activity.<ref name=":5" /> This means that in summer, the wasps are more active, performing active reproduction, while in the winter the number of reproductives dies off, and no reproductive activity is observed.<ref name=":5" />
''R. romandi'' is a swarm-founding species, which means its colonies are founded by a swarm of workers associating with queens (fertilized females).<ref name=":7" /> This is in contrast to what happens in independent-founding species, where the colony is founded by only one or a few fertilized females.<ref name=":7" /> ''R. romandi'' has been found to manage [[perennial]] nests that can last a few years.<ref name=":5" /> This means that the colony does not die off in the winter as they do in [[Year|annual]] colonies, but they instead survive the winter and manage the same nest the following season.<ref name=":5" /> Because of this, swarm-founding species normally have larger colonies with more queens than independent-founding species.<ref name=":9" /> Colony survival over the winter is thought to be possible because ''R. romandi'' practices seasonal colony activity.<ref name=":5" /> This means that in summer, the wasps are more active, performing active reproduction, while in the winter the number of reproductives dies off, and no reproductive activity is observed.<ref name=":5" />


There is also a difference in colony [[foraging]] behavior between the winter and summer seasons. Workers can be seen foraging for flower nectar (which has lots of [[carbohydrates]]) much more frequently in the winter than in the summer, suggesting that the wasps use these carbohydrates as energy stores to survive the winter. These energy stores make it possible for the wasps to not take any active flights for up to a week, which is beneficial because they avoid the cool temperatures and often rainy weather.<ref name=":5" />
There is also a difference in colony [[foraging]] behavior between the winter and summer seasons. Workers can be seen foraging for flower nectar (which is rich in [[carbohydrates]]) much more frequently in the winter than in the summer, suggesting that the wasps use these carbohydrates as energy stores to survive the winter. These energy stores make it possible for the wasps to not take any active flights for up to a week, which is beneficial because they avoid the cool temperatures and often rainy weather.<ref name=":5" />


During ''R. romandi''<nowiki/>'s colony cycle, there is a large difference in the composition of the cells within the nest. Winter nests have more nectar deposits in cells than larva. In contrast, summer nests have only 1% of their cells filled with nectar, while the rest contain developing immatures.<ref name=":5" /> This again points to the seasonal colony activity of ''R. romandi'' with more reproductive activity, and therefore brood raising, occurring in the summer, and more foraging behavior and nectar storing occurring during the winter.<ref name=":5" />
During ''R. romandi''<nowiki/>'s colony cycle, there is a large difference in the composition of the cells within the nest. Winter nests have more nectar deposits in cells than larva. In contrast, summer nests have only 1% of their cells filled with nectar, while the rest contain developing immatures.<ref name=":5" /> This again points to the seasonal colony activity of ''R. romandi'' with more reproductive activity, and therefore brood raising, occurring in the summer, and more foraging behavior and nectar storing occurring during the winter.<ref name=":5" />


==Swarm-founding==
==Swarm-founding==
The genus ''Ropalidia ''is unique because it contains both independent and swarm-founding species.<ref name=":2" /> ''R. romandi ''is a swarm founding species'', ''meaning that new nests are founded by a large group of workers with a smaller number of inseminated females (egg-laying queens).<ref name=":10">{{Cite book|title = The Evolution of Social Wasps|last = Hunt|first = James H.|publisher = Oxford University Press|year = 2007|isbn = |location = |pages = 57–60}}</ref> There are two different types of swarms: reproductive and [[Swarming (honey bee)|absconding]].<ref name=":10" /> A reproductive swarm is made up of some females of an already established colony, who depart to form a new colony with a group of workers.<ref name=":10" /> On the other hand, absconding swarms, a continuation of the existing colony, are made up of all the members of a colony.<ref name=":10" /> ''R. romandi'' is thought to utilize both forms of swarming,<ref name=":3" /> however, not much is known about reproductive swarming in ''Ropalidia ''<ref>Jeanne, R. L. "The Swarm-founding Polistinae." ''The Social Biology of Wasps''. Ed. K. G. Ross and R. W. Matthews. Ithaca, London: Cornell UP, 1991. 191–231. Print.
The genus ''Ropalidia'' is unique because it contains both independent and swarm-founding species.<ref name=":2" /> ''R. romandi'' is a swarm founding species, meaning that new nests are founded by a large group of workers with a smaller number of inseminated females (egg-laying queens).<ref name=":10">{{Cite book|title = The Evolution of Social Wasps|last = Hunt|first = James H.|publisher = Oxford University Press|year = 2007|pages = 57–60}}</ref> There are two different types of swarms: reproductive and [[Swarming (honey bee)|absconding]].<ref name=":10" /> A reproductive swarm is made up of some females of an already established colony, who depart to form a new colony with a group of workers.<ref name=":10" /> On the other hand, absconding swarms, a continuation of the existing colony, are made up of all the members of a colony.<ref name=":10" /> ''R. romandi'' is thought to utilize both forms of swarming,<ref name=":3" /> however, not much is known about reproductive swarming in ''Ropalidia'' <ref>Jeanne, R. L. "The Swarm-founding Polistinae." ''The Social Biology of Wasps''. Ed. K. G. Ross and R. W. Matthews. Ithaca, London: Cornell UP, 1991. 191–231. Print.
</ref> and most research on ''R. romandi ''has been on absconding swarms. It has been found that ''R. romandi ''will abscond if their nest is destroyed, damaged, or continually disturbed.<ref name=":3" /><ref name=":8" />
</ref> and most research on ''R. romandi'' has been on absconding swarms. It has been found that ''R. romandi'' will abscond if their nest is destroyed, damaged, or continually disturbed.<ref name=":3" /><ref name=":8" />


===Absconding process===
===Absconding process===
During the absconding process, the workers, rather than the queen, choose the new nesting site, behaviour characteristic of independent founding species.<ref name=":3" /> It has been hypothesized that the process is mediated by [[pheromones]].<ref name=":3" /><ref name=":10" /> During their search for a new nesting site, ''R. romandi'' workers have been observed to exhibit a behavior called ‘metasomal dragging’.<ref name=":3" /> This means that the wasp drags its [[Metasoma|metasome]] or [[gaster (insect anatomy)|gaster]], the second abdominal segment and sections posterior to it, along objects on which it lands.<ref name=":3" /> These objects are usually leaves, rocks, or man made structures.<ref name=":10" /> There are glands on the underside of the gaster that leave a scent behind for the other workers and the queens to follow.<ref name=":3" /> Wasps that didn't exhibit metasomal dragging can often be seen inspecting objects with their antennae, presumably following the scent trail.<ref name=":3" /> This pheromone path helps recruit all other members of the colony to the new nesting site.<ref name=":3" /> Visual information may also be very important during the ''R. romandi'' absconding process,<ref name=":3" /> and may even be the ultimate signal identifying the new nesting site. As wasps continue to make their way to the new nesting site, they can be seen orienting themselves to aerial swarms that had formed around the new site.<ref name=":3" /> This orientation to aerial swarms has been observed in the absence of continued metasomal dragging as well, leading to the hypothesis that the visual cue of the aerial swarm is the indication of the final nesting site.<ref name=":3" />
During the absconding process, the workers, rather than the queen, choose the new nesting site, behaviour characteristic of independent founding species.<ref name=":3" /> It has been hypothesized that the process is mediated by [[pheromones]].<ref name=":3" /><ref name=":10" /> During their search for a new nesting site, ''R. romandi'' workers have been observed to exhibit a behavior called ‘metasomal dragging’.<ref name=":3" /> This means that the wasp drags its [[Metasoma|metasome]] or [[gaster (insect anatomy)|gaster]], the second abdominal segment and sections posterior to it, along objects on which it lands.<ref name=":3" /> These objects are usually leaves, rocks, or man made structures.<ref name=":10" /> There are glands on the underside of the gaster that leave a scent behind for the other workers and the queens to follow.<ref name=":3" /> Wasps that didn't exhibit metasomal dragging can often be seen inspecting objects with their antennae, presumably following the scent trail.<ref name=":3" /> This pheromone path helps recruit all other members of the colony to the new nesting site.<ref name=":3" /> Visual information may also be very important during the ''R. romandi'' absconding process,<ref name=":3" /> and may even be the ultimate signal identifying the new nesting site. As wasps continue to make their way to the new nesting site, they can be seen orienting themselves to aerial swarms that had formed around the new site.<ref name=":3" /> This orientation to aerial swarms has been observed in the absence of continued metasomal dragging as well, leading to the hypothesis that the visual cue of the aerial swarm is the indication of the final nesting site.<ref name=":3" />


===Aggressiveness during swarming===
===Aggressiveness during swarming===
''R. romandi, ''along with other swarm-founding wasps, can be quite aggressive during the swarming process. They are aggressive towards humans, non-nestmates, and to each other.<ref name=":3" /> Aggressiveness towards humans may result in stings, while aggressiveness towards other wasps involves biting of the body, legs or wings.<ref name=":3" /> Workers are more often the aggressors, while queens are more often the victims.<ref name=":3" /> In ''R. romandi'', workers do not always act out against non-nestmates. If different colonies of ''R. romandi'' are introduced to each other during the absconding process, they will cluster together and relatively little violence is exhibited against non-nestmate queens at this stage. If a queen is introduced after new colony formation, however, she will be vigorously attacked.<ref name=":3" /> It has been hypothesized that this means that ''R. romandi ''workers test out different queens during the absconding process.<ref name=":3" />
''R. romandi'', along with other swarm-founding wasps, can be quite aggressive during the swarming process. They are aggressive towards humans, non-nestmates, and to each other.<ref name=":3" /> Aggressiveness towards humans may result in stings, while aggressiveness towards other wasps involves biting of the body, legs or wings.<ref name=":3" /> Workers are more often the aggressors, while queens are more often the victims.<ref name=":3" /> In ''R. romandi'', workers do not always act out against non-nestmates. If different colonies of ''R. romandi'' are introduced to each other during the absconding process, they will cluster together and relatively little violence is exhibited against non-nestmate queens at this stage. If a queen is introduced after new colony formation, however, she will be vigorously attacked.<ref name=":3" /> It has been hypothesized that this means that ''R. romandi'' workers test out different queens during the absconding process.<ref name=":3" />


==Genetic relatedness in colonies==
==Genetic relatedness in colonies==
Because swarm-founding colonies can contain more than one egg-laying queen, they tend to challenge the kin selection theory and typically do not meet Hamilton’s rule of [[haplodiploid]] species mentioned in the introduction.<ref name=":11">{{Cite journal|url = |title = Genetical and morphological colony structure of the Australian swarm-founding polistine wasp, Ropalidia romandi (Hymenoptera, Vespidae)|last = Tsuchida|first = K.|date = 2000|journal = Insectes Sociaux|accessdate = |doi = 10.1007/PL00001688|pmid = |last2 = et|first2 = al.|issue = 2|volume = 47 |pages=113–116}}</ref> In comparison to other swarm-founding species, these theories are challenged further in ''R. romandi''. ''R. romandi ''colonies are extremely large, and can have an average of up to 400 queens at any one time.<ref name=":11" /> The average for other swarm-founding species is only around 20 queens.<ref name=":11" /> Having such a large number of queens decreases the genetic relatedness within the nest. Workers in ''R. romandi'' have a genetic relatedness of only 0.16, and queens have a genetic relatedness of only 0.34.<ref name=":11" /> The next lowest genetic relatedness among a swarm founding species is found in ''[[Polybia emaciata]]'' 's 0.24 among workers and 0.55 among queens.<ref>{{Cite journal|url = |title = Demographic and genetic evidence for cyclical changes in queen number in neo-tropical wasp, Polybia emaciata|last = Strassmann|first = J. E.|date = 1992|journal = The American Naturalist|accessdate = |doi = 10.1086/285417|pmid = |last2 = et|first2 = al.|issue = 3|volume = 140 |pages=363}}</ref> These numbers indicate a large deviation from Hamilton’s ¾ rule. Independent-founding species, with fewer queens, are much more likely to be more genetically related.<ref name=":11" />
Because swarm-founding colonies can contain more than one egg-laying queen, they tend to challenge the kin selection theory and typically do not meet Hamilton's rule of [[haplodiploid]] species mentioned in the introduction.<ref name=":112"/> In comparison to other swarm-founding species, these theories are challenged further in ''R. romandi''. ''R. romandi'' colonies are extremely large, and can have an average of up to 400 queens at any one time.<ref name=":112"/> The average for other swarm-founding species is only around 20 queens.<ref name=":112"/> Having such a large number of queens decreases the genetic relatedness within the nest. Workers in ''R. romandi'' have a genetic relatedness of only 0.16, and queens have a genetic relatedness of only 0.34.<ref name=":112"/> The next lowest genetic relatedness among a swarm founding species is found in ''[[Polybia emaciata]]'' 's 0.24 among workers and 0.55 among queens.<ref>{{Cite journal|title = Demographic and genetic evidence for cyclical changes in queen number in neo-tropical wasp, Polybia emaciata|last1 = Strassmann|first1 = J. E.|date = 1992|journal = The American Naturalist|doi = 10.1086/285417|pmid = 19426048|last2 = et|first2 = al.|issue = 3|volume = 140 |pages=363–372|s2cid = 41757818}}</ref> These numbers indicate a large deviation from Hamilton's ¾ rule. Independent-founding species, with fewer queens, are much more likely to be more genetically related.<ref name=":112"/>


It has also been suggested that ''R. romandi'' practices cyclical oligogyny, which is a phenomenon where new queens are made when the number of queens is reduced.<ref>{{Cite journal|url = |title = Queen number and genetic relatedness in a neotropical wasp, Polybia occidentalis.|last = Queller|first = D. C.|date = 1993|journal = Behavioral Ecolocy|accessdate = |doi = |pmid = |last2 = et|first2 = al.|volume = 4|issue = }}</ref> This was hypothesized because a difference was found between the number of effective queens in a colony, and the mean number of queens.<ref name=":11" />
It has also been suggested that ''R. romandi'' practices cyclical oligogyny, which is a phenomenon where new queens are made when the number of queens is reduced.<ref>{{Cite journal|title = Queen number and genetic relatedness in a neotropical wasp, Polybia occidentalis.|last = Queller|first = D. C.|date = 1993|journal = Behavioral Ecology|display-authors=etal|volume = 4|doi=10.1093/beheco/4.1.7|pages = 7–13 }}</ref> This was hypothesized because a difference was found between the number of effective queens in a colony, and the mean number of queens.<ref name=":112"/>


==Morphological caste differences==
==Morphological caste differences==
It has been found that ''R. romandi'' queens and workers differ in size and body shape, however these differences vary between colonies and are sometimes insignificant.<ref name=":7" /> If worker-queen dimorphism is present, the largest observable difference is between the metasome, with queens having larger metasoma, and longer and more reddish second metasomal segments.<ref name=":7" /> The most significant difference between queens and workers is between the developmental condition of their ovaries.<ref name=":7" /> Queens have ovaries in which all ovarioles have mature or semi mature oocytes, and they show sequential development of [[oocytes]].<ref name=":7" /> Workers, on the other hand, have [[ovariole|ovarioles]] that are filamentous or have only partially developed oocytes. Some individuals have ovaries that are between the queen and worker stages. These wasps are thought to be workers that become egg laying during swarming events, or they may be young uninseminated queens.<ref name=":7" />
It has been found that ''R. romandi'' queens and workers differ in size and body shape, however these differences vary between colonies and are sometimes insignificant.<ref name=":7" /> If worker-queen dimorphism is present, the largest observable difference is between the metasome, with queens having larger metasoma, and longer and more reddish second metasomal segments.<ref name=":7" /> The most significant difference between queens and workers is between the developmental condition of their ovaries.<ref name=":7" /> Queens have ovaries in which all ovarioles have mature or semi mature oocytes, and they show sequential development of [[oocytes]].<ref name=":7" /> Workers, on the other hand, have [[ovariole]]s that are filamentous or have only partially developed oocytes. Some individuals have ovaries that are between the queen and worker stages. These wasps are thought to be workers that become egg laying during swarming events, or they may be young uninseminated queens.<ref name=":7" />


==Parasites==
==Parasites==


A common endoparasite of ''R. romandi'' are insects of the order Strepsiperans, commonly in the family [[Stylopidae]]. Strepsipteran females are permanent endoparasites that dissolve through the cuticle of the host as larvae, create a sac from the host tissue to protect themselves from host's defenses, and then reside in the abdomen of the host, occupying up to 80% of the volume of the abdomen.<ref name=":1" /><ref>{{Cite journal|url = |title = Masquerading as self? Endoparasitic Strepsiptera (Insecta) enclose themselves in host-derived epidermal bag|last = Kathirithamby|first = J.|date = 2003|journal = Proceedings of the National Academy of Sciences|accessdate = |doi = 10.1073/pnas.1131999100|pmid = |last2 = et|authorlink2 = |first2 = al.|volume = 100|issue = 13 |pages=7655–7659}}</ref> These parasites can cause sterility, sometimes causing ovaries and spermathecae to become unrecognizable,<ref name=":7" /> and often change the host morphology and behavior.<ref name=":12">Kathirithamby, J. "Strepsiptera." ''Insects of Australia: A Textbook for Students and Research Workers''. 2nd ed. N.p.: Melbourne UP, 1991. 684–95. Print.
A common endoparasite of ''R. romandi'' are insects of the order Strepsiperans, commonly in the family [[Stylopidae]]. Strepsipteran females are permanent endoparasites that dissolve through the cuticle of the host as larvae, create a sac from the host tissue to protect themselves from host's defenses, and then reside in the abdomen of the host, occupying up to 80% of the volume of the abdomen.<ref name=":1" /><ref>{{Cite journal|title = Masquerading as self? Endoparasitic Strepsiptera (Insecta) enclose themselves in host-derived epidermal bag|last1 = Kathirithamby|first1 = J.|date = 2003|journal = Proceedings of the National Academy of Sciences|doi = 10.1073/pnas.1131999100|pmid = 12788973|last2 = et|first2 = al.|volume = 100|issue = 13 |pages=7655–7659 |pmc=164643|bibcode = 2003PNAS..100.7655K|doi-access = free}}</ref> These parasites can cause sterility, sometimes causing ovaries and spermathecae to become unrecognizable,<ref name=":7" /> and often change the host morphology and behavior.<ref name=":12">Kathirithamby, J. "Strepsiptera." ''Insects of Australia: A Textbook for Students and Research Workers''. 2nd ed. N.p.: Melbourne UP, 1991. 684–95. Print.</ref> However, they do not kill their host, and it has even been suggested that they can prolong their host's life.<ref name=":12" /> ''R. romandi'' often has multiple stylopisation,<ref name=":1" /> meaning they carry more than one Stylopid endoparasite at a time.
</ref> However, they do not kill their host, and it has even been suggested that they can prolong their host's life.<ref name=":12" /> ''R. romandi'' often has multiple stylopisation,<ref name=":1" /> meaning they carry more than one Stylopid endoparasite at a time.


Additionally, ''R. romandi'' broods can be attacked by [[hornet]]s.<ref name=":10" /> The hornets take larvae from the nest, sometimes over a period of just days, sometimes over weeks.<ref name=":10" /> It has been hypothesized that the envelope of a nest functions to reduce exposure to parasites.<ref>{{Cite journal|url = |title = Envelopes protect social wasps' nests from phorid infestation (Hymenoptera: Vespidae, Diptera: Phoridae)|last = London|first = K. B.|date = 1998|journal = Journal of Kansas Entomological Society|accessdate = |doi = |pmid = |last2 = Jeanne|first2 = R. L.|issue = |volume = 71}}</ref>
Additionally, ''R. romandi'' broods can be attacked by [[hornet]]s.<ref name=":10" /> The hornets take larvae from the nest, sometimes over a period of just days, sometimes over weeks.<ref name=":10" /> It has been hypothesized that the envelope of a nest functions to reduce exposure to parasites.<ref>{{Cite journal|title = Envelopes protect social wasps' nests from phorid infestation (Hymenoptera: Vespidae, Diptera: Phoridae)|last1 = London|first1 = K. B.|date = 1998|journal = Journal of the Kansas Entomological Society|last2 = Jeanne|first2 = R. L.|volume = 71}}</ref>


==Nest development==
==Nest development==
Consisting of a papery envelope covering several horizontal combs, ''R. romandi'' nests are referred to as ‘paper bag nests’ <ref name=":9" /> because they are made of plant fibers glued together with saliva yo form a dry papery substance. <ref name=":2" /> The nests can be up to one meter long<ref name=":8" /> and are usually off the ground in trees or eaves of buildings. To begin building a nest, a number of wasps gather at the nesting site, and begin building several combs simultaneously.<ref name=":2" /> This simultaneous building leads to semi-spiral shape within the nest because irregular connections are made when the combs are connected at their growth fronts.<ref name=":2" /> The envelope is either constructed after the construction of the first few combs or during that process; the timing of envelope construction depends on swarm size, and nest location.<ref name=":2" /> More combs are then added, and the envelope is then completed to cover all combs.<ref name=":2" /> The number of entrance holes depends on nest size.<ref name=":2" /> ''R. romandi '' never builds double sided combs<ref name=":2" /> and the number of cells in each comb varies. The cells are all of similar size, indicating that size dimorphism is insignificant in ''R. romandi ''colonies.<ref name=":2" />
Consisting of a papery envelope covering several horizontal combs, ''R. romandi'' nests are referred to as ‘paper bag nests’ <ref name=":9" /> because they are made of plant fibers glued together with saliva to form a dry papery substance.<ref name=":2" /> The nests can be up to one meter long<ref name=":8" /> and are usually off the ground in trees or eaves of buildings. To begin building a nest, a number of wasps gather at the nesting site, and begin building several combs simultaneously.<ref name=":2" /> This simultaneous building leads to semi-spiral shape within the nest because irregular connections are made when the combs are connected at their growth fronts.<ref name=":2" /> The envelope is either constructed after the construction of the first few combs or during that process; the timing of envelope construction depends on swarm size, and nest location.<ref name=":2" /> More combs are then added, and the envelope is then completed to cover all combs.<ref name=":2" /> The number of entrance holes depends on nest size.<ref name=":2" /> ''R. romandi'' never builds double sided combs<ref name=":2" /> and the number of cells in each comb varies. The cells are all of similar size, indicating that size dimorphism is insignificant in ''R. romandi ''colonies.<ref name=":2" />


===Solid surface nest architecture===
===Solid surface nest architecture===
''R. romandi ''nests are often built under the eaves of buildings. When built on such a hard surface, the nest, entirely covered by an envelope, forms a compressed hemisphere with multiple horizontal, flat combs, the largest comb being near the bottom. These combs are connected to each other within the envelope by ribbon-like pedicles.<ref name=":2" /> Cells are hexagonal and regularly arranged.<ref name=":2" /> The envelope is mostly single layered, however it can be double layered in parts.<ref name=":2" /> It is made of plant fibers and fragments and is a uniform light gray color. It is possible for the envelope to be heavily coated in saliva to the extent that the fibrous material of the envelope itself is completely hidden.<ref name=":2" /> A round entrance hole is at the bottom of the hemispherical nest.<ref name=":2" />
''R. romandi'' nests are often built under the eaves of buildings. When built on such a hard surface, the nest, entirely covered by an envelope, forms a compressed hemisphere with multiple horizontal, flat combs, the largest comb being near the bottom. These combs are connected to each other within the envelope by ribbon-like pedicels.<ref name=":2" /> Cells are hexagonal and regularly arranged.<ref name=":2" /> The envelope is mostly single layered, however it can be double layered in parts.<ref name=":2" /> It is made of plant fibers and fragments and is a uniform light gray color. It is possible for the envelope to be heavily coated in saliva to the extent that the fibrous material of the envelope itself is completely hidden.<ref name=":2" /> A round entrance hole is at the bottom of the hemispherical nest.<ref name=":2" />


===Variable surface nest architecture===
===Variable surface nest architecture===
When nests are also found built among the branches of various trees, the architecture of the nest is changed because of the substrate to which it has to attach.<ref name=":2" /> The most noticeable difference is that ''R. romandi ''nests connected to branches are sphericsl rather than hemispherical and mostly double-layered, with only a few single-layered sections.<ref name=":2" /> The envelope is not a gray color, but instead a creamy brown, suggesting differences in the plants available to construct the nest. The saliva coating of the envelope is thicker when built in trees, suggesting that the thickness of the coat might be related to the rain exposure of the nest location.<ref name=":2" /> Instead of a roof, the nests often use leaves from the tree, incorporated into the envelope, to cover the top of the nest. The number of combs in a branch-built nest is almost double that of one built on a solid surface, however they are much more irregular in shape and arrangement.<ref name=":2" />
When nests are also found built among the branches of various trees, the architecture of the nest is changed because of the substrate to which it has to attach.<ref name=":2" /> The most noticeable difference is that ''R. romandi'' nests connected to branches are spherical rather than hemispherical and mostly double-layered, with only a few single-layered sections.<ref name=":2" /> The envelope is not a gray color, but instead a creamy brown, suggesting differences in the plants available to construct the nest. The saliva coating of the envelope is thicker when built in trees, suggesting that the thickness of the coat might be related to the rain exposure of the nest location.<ref name=":2" /> Instead of a roof, the nests often use leaves from the tree, incorporated into the envelope, to cover the top of the nest. The number of combs in a branch-built nest is almost double that of one built on a solid surface, however they are much more irregular in shape and arrangement.<ref name=":2" />


==Human importance==
==Human importance==
While all wasp stings are unpleasant, the [[Stinger|sting]] of ''R. romandi ''is known for being very painful.<ref name=":0" /><ref name=":4" /> Additionally, because ''R. romandi '' is a paper wasp, it has the ability to repeatedly sting without dying.<ref name=":6">{{Cite web|url = http://www.possumman.com.au/paper-wasps-biology/|title = Peter the Possum and Bird Man|date = |accessdate = October 13, 2014|website = |publisher = |last = |first = }}</ref> ''R. romandi'' is most aggressive if they are'' ''swarming,<ref name=":3" /> if their nests are disturbed or if the wasps feel their nest is threatened.<ref name=":8" /> If wasps feel threatened, they may swarm out of the nest, and pursue the aggressor.<ref name=":8" /> If you ever get swarmed by wasps, it is recommended that you remain as still as possible and move away slowly. Sudden movements will be regarded as aggressive acts and will result in more stings.<ref name=":6" />
While all wasp stings are unpleasant, the [[Stinger|sting]] of ''R. romandi'' is known for being very painful.<ref name=":0" /><ref name=":4" /> Additionally, because ''R. romandi'' is a paper wasp, it has the ability to repeatedly sting without dying.<ref name=":6">{{Cite web|url = http://www.possumman.com.au/paper-wasps-biology/|title = Peter the Possum and Bird Man|access-date = October 13, 2014}}</ref> ''R. romandi'' is most aggressive if they are'' ''swarming,<ref name=":3" /> if their nests are disturbed or if the wasps feel their nest is threatened.<ref name=":8" /> If wasps feel threatened, they may swarm out of the nest, and pursue the aggressor.<ref name=":8" /> If you ever get swarmed by wasps, it is recommended that you remain as still as possible and move away slowly. Sudden movements will be regarded as aggressive acts and will result in more stings.<ref name=":6" />


If stung, the site will appear red and may remain itchy and swollen for many days.<ref name=":8" /> The best treatment of stings is to first wash the area with soap and water, then use an antiseptic, and if swelling remains apply an ice pack.<ref name=":8" /> Many people are allergic to wasp venom, and if this is the case, a sting can result in severe [[anaphylactic shock]].<ref name=":6" /><ref name=":8" /> Symptoms of this include swelling of airways, including mouth lips and tongue, troubled breathing, dizziness and tightness of chest.<ref name=":6" /> If an individual exhibits any of these symptoms after acquiring a sting from ''R. romandi ''seek medical attention immediately.<ref name=":6" />
If stung, the site will appear red and may remain itchy and swollen for many days.<ref name=":8" /> The best treatment of stings is to first wash the area with soap and water, then use an antiseptic, and if swelling remains apply an ice pack.<ref name=":8" /> Many people are allergic to wasp venom, and if this is the case, a sting can result in severe [[anaphylactic shock]].<ref name=":6" /><ref name=":8" /> Symptoms of this include swelling of airways, including mouth lips and tongue, troubled breathing, dizziness and tightness of chest.<ref name=":6" /> If an individual exhibits any of these symptoms after acquiring a sting from ''R. romandi ''seek medical attention immediately.<ref name=":6" />


Because ''R. romandi ''nests can often be found on buildings, it is common for wasp nests to be built in heavily human populated areas. Their nests do not cause any structural damage, so if the nests are located in out of the way areas, they are best left alone.<ref name=":6" /> Attempting to knock them down will induce the aggressive behavior described above, and ''R. romandi'' tend to rebuild nests in similar spots.<ref name=":8" /> Additionally, paper wasps feed their young on caterpillars, so they can help eliminate common garden and agricultural pests.<ref name=":8" /> If one does have to get rid of a nest, it is recommended that the job is done by a professional exterminator, or with a fast acting can of [[insecticide]].<ref name=":6" /><ref name=":8" /> The best time to get rid of an ''R. romandi'' nest is at dawn or after dark when the wasps are most docile.<ref name=":8" />
Because ''R. romandi'' nests can often be found on buildings, it is common for wasp nests to be built in heavily human populated areas. Their nests do not cause any structural damage, so if the nests are located in out of the way areas, they are best left alone.<ref name=":6" /> Attempting to knock them down will induce the aggressive behavior described above, and ''R. romandi'' tend to rebuild nests in similar spots.<ref name=":8" /> Additionally, paper wasps feed their young on caterpillars, so they can help eliminate common garden and agricultural pests.<ref name=":8" /> If one does have to get rid of a nest, it is recommended that the job is done by a professional exterminator, or with a fast acting can of [[insecticide]].<ref name=":6" /><ref name=":8" /> The best time to get rid of an ''R. romandi'' nest is at dawn or after dark when the wasps are most docile.<ref name=":8" />


==Diet==
==Diet==
Paper wasps such as ''R. romandi ''are known to feed their young on caterpillars.<ref name=":8" /> Additionally, they feed on the nectar of many flowering trees, including ''[[Syzygium cormiflorum]]'' and'' [[Acacia oraria]]''.<ref name=":5" /> Flower nectar foraging behavior increases during the Austral winter, and is thought to be due to the fact that the high carbohydrate level of flower nectar allows the colony to survive the winter.<ref name=":5" /> ''R. romandi'' shows another interesting activity in the winter: they are seen foraging for honeydew from [[scale insects]].<ref name=":5" /> They have been observed defending and protecting the scale insects against other wasps.<ref name=":5" />
Paper wasps such as ''R. romandi'' are known to feed their young on caterpillars.<ref name=":8" /> Additionally, they feed on the nectar of many flowering trees, including ''[[Syzygium cormiflorum]]'' and ''[[Acacia oraria]]''.<ref name=":5" /> Flower nectar foraging behavior increases during the Austral winter, and is thought to be due to the fact that the high carbohydrate level of flower nectar allows the colony to survive the winter.<ref name=":5" /> ''R. romandi'' shows another interesting activity in the winter: they are seen foraging for honeydew from [[scale insects]].<ref name=":5" /> They have been observed defending and protecting the scale insects against other wasps.<ref name=":5" />


==References==
==References==
{{Reflist}}
{{Reflist}}

{{Taxonbar|from=Q14425368}}


[[Category:Vespidae]]
[[Category:Vespidae]]
[[Category:Hymenoptera of Australia]]
[[Category:Hymenoptera of Australia]]
[[Category:Insects described in 1841]]

Latest revision as of 01:43, 24 June 2023

Yellow Paper Wasp
Burdekin River, Queensland
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Vespidae
Subfamily: Polistinae
Tribe: Ropalidiini
Genus: Ropalidia
Species:
R. romandi
Binomial name
Ropalidia romandi
(Le Guillou, 1841)

Ropalidia romandi, also known as the yellow brown paper wasp[1] or the yellow paper wasp.[2] is a species of paper wasp found in Northern and Eastern Australia. R. romandi is a swarm-founding wasp, and manages perennial nests.[3] Its nests are known as 'paper bag nests'[4] and have different architectural structures, depending on the substrates from which they are built.[5] The specific name honors Gustave, baron de Romand, a prominent French political figure and amateur entomologist.

Because swarm-founding colonies can contain more than one egg-laying queen, they tend to challenge current kin selection theory. in that they do not meet William D. Hamilton’s rule of haplodiploid eusocial Hymenoptera, in which all the sisters from a single mating of one queen with a parthenogenetically-produced male will share 75% of their genes.[6] This wasp often has multiple strepsipteran endoparasites,[7] and it delivers a very painful sting when threatened.[1][2]

Taxonomy and phylogeny

[edit]

Ropalidia romandi, first named by Élie Jean François Le Guillou in 1841,[7] is in the subfamily Polistinae. It contains two subspecies, R. romandi romandi (Le Guillou 1841) and R. romandi cabeti (de Saussure 1853).[8] Ropalidia is the only genus in Polistinae that contains both independent-founding species, founded by only one or a few fertilized females, and swarm-founding species.[5] Swarm-founding species within Ropalidia must thus have evolved independently from swarm-founding species found in other polistine genera.[9] This genus is distributed across Oceania and the Old World,[5] and contains approximately 180 species.[10] It and the other three Old World polistine genera form a monophyletic group.[10]

Description

[edit]
Wasp morphology

Ropalidia romandi is unique for its overall yellow color, with dark brown markings on its thorax and abdomen.[2][11] Measuring around 12mm, R. romandi is considered small.[1] The first segment of the abdomen in Ropalidia is narrower than the following segments. R. romandi's front wings fold lengthwise when resting, which is a common characteristic of paper wasps.[12]

Its nest is referred to as ‘paper bag nest’[4] because it consists of a papery envelope covering several horizontal combs.[5] Both the envelope and its contents are made of papery plant fibers glued together with saliva.[5] The nest is either spherical or hemispherical in shape, can be up to one meter long, and is usually found in trees or eaves of buildings.[12][5]

Distribution and habitat

[edit]

In Australia R. romandi is found in Northern Territory and Queensland.[3] It is one of the most common paper wasp species in Eastern Queensland.[5] R. romandi lives in both tropical and temperate climates. However, their habitats are prone to cold winters, which results in seasonal colony activity.[3] Nests can be found hanging from the underside of various tree branches and building eaves at anywhere from 2.5m to 30m above the ground.[4][13] They commonly attach their nests to Eucalypts, which shed their bark frequently. When this occurs, the nests fall to the ground and are abandoned by the colony. Shortly after, a new nest is constructed.[12]

Colony cycle

[edit]

R. romandi is a swarm-founding species, which means its colonies are founded by a swarm of workers associating with queens (fertilized females).[10] This is in contrast to what happens in independent-founding species, where the colony is founded by only one or a few fertilized females.[10] R. romandi has been found to manage perennial nests that can last a few years.[3] This means that the colony does not die off in the winter as they do in annual colonies, but they instead survive the winter and manage the same nest the following season.[3] Because of this, swarm-founding species normally have larger colonies with more queens than independent-founding species.[4] Colony survival over the winter is thought to be possible because R. romandi practices seasonal colony activity.[3] This means that in summer, the wasps are more active, performing active reproduction, while in the winter the number of reproductives dies off, and no reproductive activity is observed.[3]

There is also a difference in colony foraging behavior between the winter and summer seasons. Workers can be seen foraging for flower nectar (which is rich in carbohydrates) much more frequently in the winter than in the summer, suggesting that the wasps use these carbohydrates as energy stores to survive the winter. These energy stores make it possible for the wasps to not take any active flights for up to a week, which is beneficial because they avoid the cool temperatures and often rainy weather.[3]

During R. romandi's colony cycle, there is a large difference in the composition of the cells within the nest. Winter nests have more nectar deposits in cells than larva. In contrast, summer nests have only 1% of their cells filled with nectar, while the rest contain developing immatures.[3] This again points to the seasonal colony activity of R. romandi with more reproductive activity, and therefore brood raising, occurring in the summer, and more foraging behavior and nectar storing occurring during the winter.[3]

Swarm-founding

[edit]

The genus Ropalidia is unique because it contains both independent and swarm-founding species.[5] R. romandi is a swarm founding species, meaning that new nests are founded by a large group of workers with a smaller number of inseminated females (egg-laying queens).[14] There are two different types of swarms: reproductive and absconding.[14] A reproductive swarm is made up of some females of an already established colony, who depart to form a new colony with a group of workers.[14] On the other hand, absconding swarms, a continuation of the existing colony, are made up of all the members of a colony.[14] R. romandi is thought to utilize both forms of swarming,[9] however, not much is known about reproductive swarming in Ropalidia [15] and most research on R. romandi has been on absconding swarms. It has been found that R. romandi will abscond if their nest is destroyed, damaged, or continually disturbed.[9][12]

Absconding process

[edit]

During the absconding process, the workers, rather than the queen, choose the new nesting site, behaviour characteristic of independent founding species.[9] It has been hypothesized that the process is mediated by pheromones.[9][14] During their search for a new nesting site, R. romandi workers have been observed to exhibit a behavior called ‘metasomal dragging’.[9] This means that the wasp drags its metasome or gaster, the second abdominal segment and sections posterior to it, along objects on which it lands.[9] These objects are usually leaves, rocks, or man made structures.[14] There are glands on the underside of the gaster that leave a scent behind for the other workers and the queens to follow.[9] Wasps that didn't exhibit metasomal dragging can often be seen inspecting objects with their antennae, presumably following the scent trail.[9] This pheromone path helps recruit all other members of the colony to the new nesting site.[9] Visual information may also be very important during the R. romandi absconding process,[9] and may even be the ultimate signal identifying the new nesting site. As wasps continue to make their way to the new nesting site, they can be seen orienting themselves to aerial swarms that had formed around the new site.[9] This orientation to aerial swarms has been observed in the absence of continued metasomal dragging as well, leading to the hypothesis that the visual cue of the aerial swarm is the indication of the final nesting site.[9]

Aggressiveness during swarming

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R. romandi, along with other swarm-founding wasps, can be quite aggressive during the swarming process. They are aggressive towards humans, non-nestmates, and to each other.[9] Aggressiveness towards humans may result in stings, while aggressiveness towards other wasps involves biting of the body, legs or wings.[9] Workers are more often the aggressors, while queens are more often the victims.[9] In R. romandi, workers do not always act out against non-nestmates. If different colonies of R. romandi are introduced to each other during the absconding process, they will cluster together and relatively little violence is exhibited against non-nestmate queens at this stage. If a queen is introduced after new colony formation, however, she will be vigorously attacked.[9] It has been hypothesized that this means that R. romandi workers test out different queens during the absconding process.[9]

Genetic relatedness in colonies

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Because swarm-founding colonies can contain more than one egg-laying queen, they tend to challenge the kin selection theory and typically do not meet Hamilton's rule of haplodiploid species mentioned in the introduction.[6] In comparison to other swarm-founding species, these theories are challenged further in R. romandi. R. romandi colonies are extremely large, and can have an average of up to 400 queens at any one time.[6] The average for other swarm-founding species is only around 20 queens.[6] Having such a large number of queens decreases the genetic relatedness within the nest. Workers in R. romandi have a genetic relatedness of only 0.16, and queens have a genetic relatedness of only 0.34.[6] The next lowest genetic relatedness among a swarm founding species is found in Polybia emaciata 's 0.24 among workers and 0.55 among queens.[16] These numbers indicate a large deviation from Hamilton's ¾ rule. Independent-founding species, with fewer queens, are much more likely to be more genetically related.[6]

It has also been suggested that R. romandi practices cyclical oligogyny, which is a phenomenon where new queens are made when the number of queens is reduced.[17] This was hypothesized because a difference was found between the number of effective queens in a colony, and the mean number of queens.[6]

Morphological caste differences

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It has been found that R. romandi queens and workers differ in size and body shape, however these differences vary between colonies and are sometimes insignificant.[10] If worker-queen dimorphism is present, the largest observable difference is between the metasome, with queens having larger metasoma, and longer and more reddish second metasomal segments.[10] The most significant difference between queens and workers is between the developmental condition of their ovaries.[10] Queens have ovaries in which all ovarioles have mature or semi mature oocytes, and they show sequential development of oocytes.[10] Workers, on the other hand, have ovarioles that are filamentous or have only partially developed oocytes. Some individuals have ovaries that are between the queen and worker stages. These wasps are thought to be workers that become egg laying during swarming events, or they may be young uninseminated queens.[10]

Parasites

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A common endoparasite of R. romandi are insects of the order Strepsiperans, commonly in the family Stylopidae. Strepsipteran females are permanent endoparasites that dissolve through the cuticle of the host as larvae, create a sac from the host tissue to protect themselves from host's defenses, and then reside in the abdomen of the host, occupying up to 80% of the volume of the abdomen.[7][18] These parasites can cause sterility, sometimes causing ovaries and spermathecae to become unrecognizable,[10] and often change the host morphology and behavior.[19] However, they do not kill their host, and it has even been suggested that they can prolong their host's life.[19] R. romandi often has multiple stylopisation,[7] meaning they carry more than one Stylopid endoparasite at a time.

Additionally, R. romandi broods can be attacked by hornets.[14] The hornets take larvae from the nest, sometimes over a period of just days, sometimes over weeks.[14] It has been hypothesized that the envelope of a nest functions to reduce exposure to parasites.[20]

Nest development

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Consisting of a papery envelope covering several horizontal combs, R. romandi nests are referred to as ‘paper bag nests’ [4] because they are made of plant fibers glued together with saliva to form a dry papery substance.[5] The nests can be up to one meter long[12] and are usually off the ground in trees or eaves of buildings. To begin building a nest, a number of wasps gather at the nesting site, and begin building several combs simultaneously.[5] This simultaneous building leads to semi-spiral shape within the nest because irregular connections are made when the combs are connected at their growth fronts.[5] The envelope is either constructed after the construction of the first few combs or during that process; the timing of envelope construction depends on swarm size, and nest location.[5] More combs are then added, and the envelope is then completed to cover all combs.[5] The number of entrance holes depends on nest size.[5] R. romandi never builds double sided combs[5] and the number of cells in each comb varies. The cells are all of similar size, indicating that size dimorphism is insignificant in R. romandi colonies.[5]

Solid surface nest architecture

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R. romandi nests are often built under the eaves of buildings. When built on such a hard surface, the nest, entirely covered by an envelope, forms a compressed hemisphere with multiple horizontal, flat combs, the largest comb being near the bottom. These combs are connected to each other within the envelope by ribbon-like pedicels.[5] Cells are hexagonal and regularly arranged.[5] The envelope is mostly single layered, however it can be double layered in parts.[5] It is made of plant fibers and fragments and is a uniform light gray color. It is possible for the envelope to be heavily coated in saliva to the extent that the fibrous material of the envelope itself is completely hidden.[5] A round entrance hole is at the bottom of the hemispherical nest.[5]

Variable surface nest architecture

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When nests are also found built among the branches of various trees, the architecture of the nest is changed because of the substrate to which it has to attach.[5] The most noticeable difference is that R. romandi nests connected to branches are spherical rather than hemispherical and mostly double-layered, with only a few single-layered sections.[5] The envelope is not a gray color, but instead a creamy brown, suggesting differences in the plants available to construct the nest. The saliva coating of the envelope is thicker when built in trees, suggesting that the thickness of the coat might be related to the rain exposure of the nest location.[5] Instead of a roof, the nests often use leaves from the tree, incorporated into the envelope, to cover the top of the nest. The number of combs in a branch-built nest is almost double that of one built on a solid surface, however they are much more irregular in shape and arrangement.[5]

Human importance

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While all wasp stings are unpleasant, the sting of R. romandi is known for being very painful.[1][2] Additionally, because R. romandi is a paper wasp, it has the ability to repeatedly sting without dying.[11] R. romandi is most aggressive if they are swarming,[9] if their nests are disturbed or if the wasps feel their nest is threatened.[12] If wasps feel threatened, they may swarm out of the nest, and pursue the aggressor.[12] If you ever get swarmed by wasps, it is recommended that you remain as still as possible and move away slowly. Sudden movements will be regarded as aggressive acts and will result in more stings.[11]

If stung, the site will appear red and may remain itchy and swollen for many days.[12] The best treatment of stings is to first wash the area with soap and water, then use an antiseptic, and if swelling remains apply an ice pack.[12] Many people are allergic to wasp venom, and if this is the case, a sting can result in severe anaphylactic shock.[11][12] Symptoms of this include swelling of airways, including mouth lips and tongue, troubled breathing, dizziness and tightness of chest.[11] If an individual exhibits any of these symptoms after acquiring a sting from R. romandi seek medical attention immediately.[11]

Because R. romandi nests can often be found on buildings, it is common for wasp nests to be built in heavily human populated areas. Their nests do not cause any structural damage, so if the nests are located in out of the way areas, they are best left alone.[11] Attempting to knock them down will induce the aggressive behavior described above, and R. romandi tend to rebuild nests in similar spots.[12] Additionally, paper wasps feed their young on caterpillars, so they can help eliminate common garden and agricultural pests.[12] If one does have to get rid of a nest, it is recommended that the job is done by a professional exterminator, or with a fast acting can of insecticide.[11][12] The best time to get rid of an R. romandi nest is at dawn or after dark when the wasps are most docile.[12]

Diet

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Paper wasps such as R. romandi are known to feed their young on caterpillars.[12] Additionally, they feed on the nectar of many flowering trees, including Syzygium cormiflorum and Acacia oraria.[3] Flower nectar foraging behavior increases during the Austral winter, and is thought to be due to the fact that the high carbohydrate level of flower nectar allows the colony to survive the winter.[3] R. romandi shows another interesting activity in the winter: they are seen foraging for honeydew from scale insects.[3] They have been observed defending and protecting the scale insects against other wasps.[3]

References

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  1. ^ a b c d "Brisbane Insects". Retrieved October 13, 2014.
  2. ^ a b c d "Insects of Townsville". Retrieved October 13, 2014.
  3. ^ a b c d e f g h i j k l m n Kojima, J. (1996). "Colony cycle of an Australian swarm-founding paper wasp, Ropalidia romandi (Hymenoptera: Vespidae)". Insectes Sociaux. 43 (4): 411–420. doi:10.1007/BF01258413. S2CID 35241710.
  4. ^ a b c d e Kojima, J. (1994). "Evidence for an alarm pheromone in Ropalidia romandi (Le Guillou) (Hymenoptera: Vespidae)". Australian Journal of Entomology. 33 (1): 45–47. doi:10.1111/j.1440-6055.1994.tb00916.x.
  5. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Yamane, Soichi; Ito, Yosiaki (1994). "Nest architecture of the Australian paper wasp Ropalidia romandi cabeti, with a note on its developmental process (Hymenoptera: Vespidae)". Psyche: A Journal of Entomology. 101 (3–4): 145–158. doi:10.1155/1994/92839.
  6. ^ a b c d e f g Tsuchida, K.; et, al. (2000). "Genetical and morphological colony structure of the Australian swarm-founding polistine wasp, Ropalidia romandi (Hymenoptera, Vespidae)". Insectes Sociaux. 47 (2): 113–116. doi:10.1007/PL00001688. S2CID 44016571.
  7. ^ a b c d Wild, Clyde H.; Hall, Casey R. (2010). "Multiple stylopisation of a paper wasp, Ropalidia romandi (Le Guillou) (Hymenoptera: Vespidae)". Australian Entomologist. 37 (3).
  8. ^ Richards, O. W. (1978). "The Australian Social Wasps (Hymenoptera: Vespidae)". Australian Journal of Zoology: Supplementary Series. 61.
  9. ^ a b c d e f g h i j k l m n o p q r s Kojima, Jun-ichi (1994). "Behavior during artificially induced swarm emigration in an old world polistine wasp, Ropalidia romandi (Hymenoptera: Vespidae)". Journal of Ethology. 12 (1): 1–8. doi:10.1007/BF02350073. S2CID 38229890.
  10. ^ a b c d e f g h i j Fukuda, Hirokazu; et, al. (2003). "Colony specific morphological caste differences in an Old World, swarm-founding polistine, Ropalidia romandi (Hymenoptera: Vespidae)". Entomological Science. 6 (1): 37–47. doi:10.1046/j.1343-8786.2003.00002.x. S2CID 84695115.
  11. ^ a b c d e f g h "Peter the Possum and Bird Man". Retrieved October 13, 2014.
  12. ^ a b c d e f g h i j k l m n o Queensland Museum (2011). "Paper Wasps: Fact Sheet". Queensland Government.
  13. ^ "Smallest Wasp Builds Biggest Nest in Forest?". Retrieved October 11, 2014.
  14. ^ a b c d e f g h Hunt, James H. (2007). The Evolution of Social Wasps. Oxford University Press. pp. 57–60.
  15. ^ Jeanne, R. L. "The Swarm-founding Polistinae." The Social Biology of Wasps. Ed. K. G. Ross and R. W. Matthews. Ithaca, London: Cornell UP, 1991. 191–231. Print.
  16. ^ Strassmann, J. E.; et, al. (1992). "Demographic and genetic evidence for cyclical changes in queen number in neo-tropical wasp, Polybia emaciata". The American Naturalist. 140 (3): 363–372. doi:10.1086/285417. PMID 19426048. S2CID 41757818.
  17. ^ Queller, D. C.; et al. (1993). "Queen number and genetic relatedness in a neotropical wasp, Polybia occidentalis". Behavioral Ecology. 4: 7–13. doi:10.1093/beheco/4.1.7.
  18. ^ Kathirithamby, J.; et, al. (2003). "Masquerading as self? Endoparasitic Strepsiptera (Insecta) enclose themselves in host-derived epidermal bag". Proceedings of the National Academy of Sciences. 100 (13): 7655–7659. Bibcode:2003PNAS..100.7655K. doi:10.1073/pnas.1131999100. PMC 164643. PMID 12788973.
  19. ^ a b Kathirithamby, J. "Strepsiptera." Insects of Australia: A Textbook for Students and Research Workers. 2nd ed. N.p.: Melbourne UP, 1991. 684–95. Print.
  20. ^ London, K. B.; Jeanne, R. L. (1998). "Envelopes protect social wasps' nests from phorid infestation (Hymenoptera: Vespidae, Diptera: Phoridae)". Journal of the Kansas Entomological Society. 71.