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Specific Venom Immunotherapy (VIT) is practiced with venom extracted from insects, and is the specific therapy used for patients highly allergic to social insect (Hymenoptera) stings. Due to the dramatic shortage of vespid species in the local environment, we coupled vespiculture techniques of Polistes paper wasps with a venom collection procedure based on the electrical stimulation of individuals from entire colonies. The procedure involves little to no disturbance of the individual insects, and at the same time, successfully allows for the extraction of venom containing all allergens necessary for VIT. [ABSTRACT FROM AUTHOR]

Honey is a healing compound produced by the Apidae bees. So far, the only genus of Apis with 9 known species worldwide is a honey bee. But species of paper wasps in the Vespidae can also produce honey. This research was conducted to study and identify the species of paper wasp honey producer in the South of Kerman. For this purpose, the activity areas of this wasp were identified, and specimens of this paper wasp were collected for species identification. The specimens were identified by keys and related articles and Confirmed by Dr. James M. Carpenter at the American Museum of natural history. Parapolybia escalerae (Meado-Waldo) was described by Mead-Waldo in the London British Museum in 1911 as a single female specimen from southwestern Iran. The World distribution of this paper wasp is in Pakistan, Turkey, and Iran. According to the results of this study, the species Parapolybia escalerae (Meado-Waldo, 1911) was identified for the first time in southeastern Iran (south of Kerman). This species was distributed south of Kerman from the tropical foothills of Jabalbarz Mountains (southern Jabalbarz to Mohammadabad) and Bahraseman. Parapolybia escalerae is introduced in the world as a paper wasp species of a honey producer. The paper wasp is known as dry or chocolate honey and has medicinal use. In this study, the male and queen specimens were collected and identified for the first time. This study found that this species of paper wasp, like the Apis florea, produces wild honey. A. florea has open nests and small colonies of a single comb, but P. escalerae is in the dark space of mountains and cliffs and produces many combs. The activity of this species was mostly observed on the Ziziphus sp. and Pistacia terebinthus trees. This paper wasp has a social life and includes three forms of queens, workers, and males. So far, only two species of Honey producing paper wasps have been reported in South America, including Brachygastra mellifica (Say, 1837), known as the Mexican Honey Wasp and Brachygastra lecheguana (Latreille, 1824), which are paper wasps belonging to the subfamily Polistinae. These two species have round nests and build their nests on tall trees and the ground in open spaces. Their honey has medicinal use in different regions of South America and is collected by local people. The paper wasp species P. escalerae works in the crevices of the rocks and has several flat combs. In Iran, the local people of the southern regions of Iran use this honey as medicine to treat respiratory diseases. [ABSTRACT FROM AUTHOR]

The genus Latibulus Gistel, 1848 (Hymenoptera: Ichneumonidae) is taxonomically reviewed in Iran. Specimens were collected using Malaise traps in the Isfahan province, during 2013–2015. Two species, Latibulus argiolus (Rossi, 1790) (spring form) and Latibulus orientalis (Horstmann, 1987) (summer form) are identified, of which L. orientalis is a new record for the fauna of Iran. In addition, L. argiolus is recorded from central part of Iran (Isfahan) for the first time. The geographical distribution of the recorded species in relation to the overall knowledge in the target area and adjacent regions is also discussed.

231 species of the family Vespidae (Hymenoptera, Vespoidea) of Iran, in 55 genera belonging to 4 subfamilies Eumeninae (45 genera, 184 species), Masarinae (5 genera, 24 species), Polistinae (2 genera, 17 species) and Vespinae (3 genera, 6 species) are listed. An overall assessment of the distribution pattern of the vespid species in Iran indicates a complex fauna of different biogeographic regions. 111 species are found in both Eastern and Western Palaearctic regions, while 67 species were found only in the Eastern Palaearctic region. Few species (14 species – 6.1%) of various genera are known as elements of central and western Asian area and their area of distribution is not known in Europe (West Palaearctic) and in the Far East. The species that were found both in the Oriental and Afrotropical Regions comprises 11.7 and 15.6% the Iranian vespid fauna, respectively. Many species (48, 20.8%) are exclusively recorded from Iran and as yet there is no record of these species from other countries. The highest percentage of the vespid species are recorded from Sistan-o Baluchestan (42 species, 18.2%), Alborz (42 species, 18.2%), Fars (39 species, 16.9%) and Tehran provinces (38 Species 16.5%), representing the fauna of the Southeastern, North- and South Central of the country.

Specific Venom Immunotherapy (VIT) is practiced with venom extracted from insects, and is the specific therapy used for patients highly allergic to social insect (Hymenoptera) stings. Due to the dramatic shortage of vespid species in the local environment, we coupled vespiculture techniques of Polistes paper wasps with a venom collection procedure based on the electrical stimulation of individuals from entire colonies. The procedure involves little to no disturbance of the individual insects, and at the same time, successfully allows for the extraction of venom containing all allergens necessary for VIT.

Refurbishing the old nest in order to prepare it for a new breeding season cycle has already been observed in few species of paper wasps. When future foundresses emerge from hibernacula they have choose between building a new nest or reusing an old one. In present paper I described a case of multiple use and further expansion an old nest by Polistes dominula (Christ, 1791) in Grodzisk Mazowiecki, Mazovia Region, Central Poland.

Nestmate recognition, i.e., the ability to discriminate nestmates from foreign individuals, is a crucial feature of insect societies, and it has been traditionally considered to be predominantly based on chemical cues. Recent empirical evidence, however, suggests a relevant plasticity in the use of different communication channels according to cue availability and reliability in different contexts. In particular, visual cues have been shown to influence various types of social recognition in several social insects, but their role in nestmate recognition is still under-investigated. We tested the hypothesis of plasticity in the use of visual and chemical recognition cues in the primitively eusocial wasp Polistes dominula, in which the availability and reliability of recognition cues vary across the colony cycle. Indeed, before the emergence of workers, P. dominula colonies are rather small (one to few individuals), and the variability in the facial pattern might allow resident wasps to use visual cues for nestmate recognition. After workers' emergence, the increase in the number of colony members reduces the reliability of visual cues, thus leaving chemical cues as the most reliable nestmate recognition cues. We thus predict a differential use of chemical and visual cues along colony life. We experimentally separated visual and chemical cues of nestmates and non-nestmates and presented them alone or in combination (with coherent or mismatched cues) to resident wasps to test which communication channel was used in the two stages and, in case, how visual and chemical cues interacted. Our results show, for the first time in a social insect, the differential use of visual and chemical cues for nestmate recognition in two different phases of colony, which supports the hypothesis of a plastic, reliability-based use of recognition cues in this species according to the different colonial contexts.

Social parasites have evolved adaptations to overcome host resistance as they infiltrate host colonies and establish there. Among the chemical adaptations, a few species are chemically “insignificant”; they are poor in recognition cues (cuticular hydrocarbons) and evade host detection. As cuticular hydrocarbons also serve a waterproofing function, chemical insignificance is beneficial as it protects parasites from being detected but is potentially harmful because it exposes parasites to desiccation stress. Here I tested whether the social parasites Polistes atrimandibularis employ behavioral water-saving strategies when they live at Polistes biglumis colonies. Observations in the field showed that parasites were less active than their cohabiting host foundresses, spent more time at the nest, and rested in the shadowy, back face of the nest, rather than at the front face, which contradicted expectations for the use of space for dominant females—typically, dominants rest at the nest front-face. These data suggest that behavioral adaptations might promote resistance to desiccation stress in chemical insignificant social parasites.

Invasive species can be particularly disruptive when they intersect with organisms of conservation concern. Stabilizing the declining eastern migratory population of monarch butterflies (Danaus plexippus) is projected to require extensive habitat restoration across multiple land use sectors including metropolitan areas. Numerous conservation programs encourage urban citizens to plant gardens with milkweeds, the obligate larval host plants of the monarch. Here, we show that predation by Polistes dominula, an invasive paper wasp that is particularly abundant in urban settings, can turn such sites into ecological traps for monarch larvae. Polistes dominula was the predominant paper wasp seen foraging in central Kentucky pollinator gardens. In 120 observed encounters with monarch larvae on milkweeds in gardens, most second to fourth instars were killed, whereas most fifth instars escaped by thrashing or dropping. The wasps bit and carried off second instars whole, whereas third and fourth instar kills were first gutted, then processed and carried away piecemeal. Predation on sentinel larvae was much higher in urban gardens than in rural settings. The wasps exploited ornamental butterfly "hibernation boxes" in pollinator gardens as nesting habitat. Polistes dominula is an under-recognized predator that may diminish the urban sector's contributions to monarch habitat restoration. [ABSTRACT FROM AUTHOR]

The Neotropical realm harbours unparalleled species richness and hence has challenged biologists to explain the cause of its high biotic diversity. Empirical studies to shed light on the processes underlying biological diversification in the Neotropics are focused mainly on vertebrates and plants, with little attention to the hyperdiverse insect fauna. Here, we use phylogenomic data from ultraconserved element (UCE) loci to reconstruct for the first time the evolutionary history of Neotropical swarm-founding social wasps (Hymenoptera, Vespidae, Epiponini). Using maximum likelihood, Bayesian, and species tree approaches we recovered a highly resolved phylogeny for epiponine wasps. Additionally, we estimated divergence dates, diversification rates, and the biogeographic history for these insects in order to test whether the group followed a 'museum' (speciation events occurred gradually over many millions of years) or 'cradle' (lineages evolved rapidly over a short time period) model of diversification. The origin of many genera and all sampled extant Epiponini species occurred during the Miocene and Plio-Pleistocene. Moreover, we detected no major shifts in the estimated diversification rate during the evolutionary history of Epiponini, suggesting a relatively gradual accumulation of lineages with low extinction rates. Several lines of evidence suggest that the Amazonian region played a major role in the evolution of Epiponini wasps. This spatio-temporal diversification pattern, most likely concurrent with climatic and landscape changes in the Neotropics during the Miocene and Pliocene, establishes the Amazonian region as the major source of Neotropical swarm-founding social wasp diversity. [ABSTRACT FROM AUTHOR]

Biocontrol agents can help reduce pest populations as part of an integrated pest management scheme, with minimal environmental consequences. However, biocontrol agents are often non-native species and require significant infrastructure; overuse of single agents results in pest resistance. Native biocontrol agents are urgently required for more sustainable multi-faceted approaches to pest management. Social wasps are natural predators of lepidopteran pests, yet their viability as native biocontrol agents is largely unknown. Here, we provide evidence that the social paper wasp Polistes satan is a successful predator on the larvae of two economically important and resilient crop pests, the sugarcane borer Diatraea saccharalis (on sugarcane Saccharum spp.) and the fall armyworm Spodoptera frugiperda (on maize Zea mays); P. satan wasps significantly reduce crop pest damage. These results provide the much-needed baseline experimental evidence that social wasps have untapped potential as native biocontrol agents for sustainable crop production and food security. [ABSTRACT FROM AUTHOR]

The social vespid wasps (Hymenoptera: Vespidae: Vespinae and Polistinae) was studied in Bhutan during 2014-2016. A total of fifteen species were collected and identified that all of them are reported as new records from Bhutan: Vespa vivax Smith, V. velutina variana van der Vecht, V. fumida van der Vecht, Dolichovespula lama (du Buysson), Vespula flaviceps Smith, V. nursei Archer, V. vulgaris (Linnaeus), V. structor (Smith), Polistes (Polistella) nigritarsus (Cameron), Parapolybia varia (Fabricius), P. nodosa van der Vecht, Ropalidia artifex (de Saussure), R. stigma (Smith), R. ornaticeps (Cameron) and R. rufoplagiata gravelyi (Dover & Rao). Diagnostic characters and geographical distribution of all species are presented.

Communication through vibrational signals is widespread among social insects and regulates crucial social activities. Females of the social wasp Polistes dominula produce substrate-borne vibrations on the combs by performing a conspicuous abdominal oscillatory behavior, known as abdominal wagging. Several studies have reported correlative evidence in support of its signaling role, but direct evidence is still lacking. Because abdominal wagging is strictly associated with the presence of larvae in the nest and with cell inspection, it has been suggested that it could be involved in adult--larvae communication. According to this hypothesis, abdominal wagging vibrations would have short-term effects related to food and trophallactic exchanges between adults and larvae by modulating salivary secretion (decreasing its amount, to prepare larvae to receive food, or stimulating the release of larval saliva to adults). Here, by using an electro-magnetic shaker, we assessed, for the first time, the short-term effects of abdominal wagging on larval behavior by recording larval responses and by measuring the amount of saliva released immediately after abdominal wagging playback. Our results show that larvae are able to perceive the substrate-borne vibrations produced by abdominal wagging and react by increasing the movement of their body, possibly in order to attract the attention of adult females during feeding nest inspection. Yet, we found that vibrations neither increase nor decrease the release of larval saliva. Our results support the hypothesis of the alleged role of vibrations in adult--larvae communications; however, they do not support the long- lasting hypothesis of salivary release modulation. [ABSTRACT FROM AUTHOR]

The Roraima state in Brazil is part of Northern Amazon, an area harboring high biodiversity and high degree of endemism. Nevertheless, there are few studies on diversity of social wasps occurring in this region. This study presents a list of social wasps (Vespidae: Polistinae) collected actively and using Malaise, Suspended and Light trap in six localities in Roraima state. A total of 85 species of 14 genera were collected. Fourty-five of these species are new distribution records to Roraima state, some species are not common found in the collections and lists of species, and some are recorded for the second time to Brazil or the Amazon region. This increase may be an indication that the Polistinae richness is probably higher in the regions studied and that Roraima may well contain a number of additional (as yet unrecorded) social wasp species. More comprehensive studies are needed in order to increase the knowledge of wasp species in Roraima, contributing to increased knowledge of the diversity in Northern Brazil.

In field experiments, an insect was trained to choose one of two visually different figures – A or B – in reference to situation (“situational learning”). Bees and wasps were shown to be able: 1) to choose A and to reject B at one location (place) of presentation of test figures and vice versa at the other location (at a distance of 1–8 m); 2) to choose A and to reject B at C-colored background and vice versa at D-colored background (at constant location). It is the first evidence of bees’ ability to make decisions depending on background color and the first evidence of wasps’ ability to perform situational learning. The described behaviors resemble “conditioned switching”, which is well known in vertebrates. Statistically significant individual differences between conspecifics have been recorded

Social wasps are common elements in Neotropics, although even elementary data about this taxon in Amazon region is partially unknown. Therefore the purpose of this work was to increase the knowledge of social wasp fauna at Jaú National Park. A total of 494 specimens of Polistinae was collected with active search, malaise trap and light trap. Forty-nine species belonging to fourteen genera were recorded. The richest genera were Polybia (14 species), Agelaia (07), Mischocyttarus (05), Apoica (04), Brachygastra (04) and Protopolybia (04); the remaining genera were represented by less than two species. The Jaccard similarity coefficient showed a higher similarity of the Jaú National Park with Ducke Reserve (Manaus, Amazonas). Four species were collected for the first time in Amazonas state Agelaia flavipennis (Ducke), Polybia affinis Du Buysson, Protopolybia nitida (Ducke) and Protopolybia sedula (de Saussure), only in Jaú National Park, showing the importance of this park for the social wasps preservation in the Amazon region. Fauna de Vespas Sociais (Hymenoptera: Vespidae: Polistinae) do Parque Nacional do Jaú, Amazonas, Brasil Resumo. Vespas sociais são elementos comuns na região neotropical, embora até mesmo a coleta de dados elementares sobre este táxon na região amazônica ainda é parcialmente desconhecido. Por isso objetivamos contribuir para o conhecimento sobre a fauna de vespas sociais que ocorrem no Parque Nacional do Jaú. Um total de 494 indivíduos de Polistinae foi coletado através de busca ativa, armadilha Malaise e armadilha luminosa. Quarenta e nove espécies de 14 gêneros foram registradas. Polybia (14 espécies), Agelaia (07), Mischocyttarus (05), Apoica (04), Brachygastra (04) e Protopolybia (04) são os gêneros com o maior número de espécies; os demais gêneros coletados foram representados por apenas duas ou uma espécie. De acordo com o coeficiente de similaridade de Jaccard, a composição de espécies de Parque Nacional do Jaú é semelhante a Reserva Ducke (Manaus, Amazonas). Agelaia flavipennis (Ducke), Polybia affinis Du Buysson, Protopolybia nitida (Ducke) e Protopolybia sedula (de Saussure) são considerados novos registros de ocorrência para o estado do Amazonas e foram coletados, até o momento, apenas no Parque Nacional do Jaú, demonstrando a importância deste parque para a preservação de vespas sociais na região amazônica.

RNA interference (RNAi) is a useful tool to assess gene function by knocking down expression of a target gene and has been used successfully in domestic and laboratory organisms. However, the use of RNAi for functional genomics has not fully extended into ecological model organisms in natural environments. Assessment of gene function in the wild is important because gene function can be environmentally and context dependent. Here, we present a case study using RNAi to assess gene function in wild paper wasps Polistes metricus, to test roles for two candidate genes ( NADH dehydrogenase ( NADHdh) and retinoid and fatty acid binding protein ( RfaBp)) in the development of reproductive castes. Previous studies have shown that these genes are upregulated in larvae that become queens compared to workers, but this pattern was reversed in the laboratory, making field-based studies necessary. We orally administered dsRNA to larvae in field colonies and found evidence of a short-term knockdown followed by a compensatory rebound in expression for RfaBp. We also observed the predicted worker-like decrease in lipid stores in NADHdh dsRNA treated wasps, suggesting a possible role for NADHdh in caste development. We discuss our results in the context of challenges for using RNAi for functional genomics in ecological model organisms in the field. [ABSTRACT FROM AUTHOR]

Intraspecific variation in sperm morphometric is widespread across animal taxa and it might be related to different aspects of sexual selection. Within social insects, it has only been documented for some bee and ant species. Here we provided a detailed description of the variation in sperm morphometric in the paper wasp Polistes simillimus Zikan (Hymenoptera Vespidae). Light microscopy, digital photography and digital analyses were used to measure sperm (total length, head and flagellum length). Considering a single population from which we sampled four colonies, seven males of each colony and 30 sperm cells of each male (total 840 cells), the overall dimensions of P. simillimus spermatozoon is: total length 107 ± 7 (80-129) µm, coefficient of variation, CV = 8%; flagellum length 91 ± 7 (62-114) µm, CV = 7%; head length 16 ± 2 (9-30) μm, CV = 9%. We found that variation in the sperm constituent parts (head and flagellum) contribute to explaining the variation in total sperm length. However, the size of these parts varies independently. Besides, sperm total length and flagellum length differed between males, but not between nestmates and between colonies, while variation in sperm head was similar across all these levels of analyses. Finally, sperm morphometric is not associated with male body size. We discussed implications of our results for the study of sperm morphometric in insects, sampling procedures for estimating species-typical sperm size in social insects and the possibility of variation in male sperm quality in social wasps. [ABSTRACT FROM AUTHOR]

Social wasps are common elements in Neotropics, although even elementary data about this taxon in the Amazon region is partially unknown. Therefore the purpose of this work was to increase the knowledge of social wasp fauna at the Ducke Reserve. One hundred and three species belonging to nineteen genera were recorded. The richest genera were Polybia (28 species), Agelaia (12) and Mischocyttarus (12). Seventy species was collected in active search, 42 species using Malaise trap, 25 suspended trap, 20 attractive trap and nine light trap. Ducke Reserve has one of the highest number of Polistinae wasps in reserves or parks in the Neotropic region.

Understanding the developmental and evolutionary processes that generate and maintain variation in natural populations remains a major challenge for modern biology. Populations of Polistes fuscatus paper wasps have highly variable colour patterns that mediate individual recognition. Previous experimental and comparative studies have provided evidence that colour pattern diversity is the result of selection for individuals to advertise their identity. Distinctive identity-signalling phenotypes facilitate recognition, which reduces aggression between familiar individuals in P. fuscatus wasps. Selection for identity signals may increase phenotypic diversity via two distinct modes of selection that have different effects on genetic diversity. Directional selection for increased plasticity would greatly increase phenotypic diversity but decrease genetic diversity at associated loci. Alternatively, heritable identity signals under balancing selection would maintain genetic diversity at associated loci. Here, we assess whether there is heritable variation underlying colour pattern diversity used for facial recognition in a wild population of P. fuscatus wasps. We find that colour patterns are heritable and not Mendelian, suggesting that multiple loci are involved. Additionally, patterns of genetic correlations among traits indicated that many of the loci underlying colour pattern variation are unlinked and independently segregating. Our results support a model where the benefits of being recognizable maintain genetic variation at multiple unlinked loci that code for phenotypic diversity used for recognition.

The aim of the present work was to discover how many species inhabit the environs of Brasília. Being an approximate rectangle in the middle of the Cerrado biome, the Federal District of Brasília is a representative “quadrat” to sample the biome’s fauna.

Eusocial insect reproductive castes (in Hymenoptera, female reproductive queens and sterile workers) differ dramatically in behavior. Castes may differ in the cognitive demands that affect patterns of brain tissue investment. Queens and workers diverge most strongly in the advanced eusocial, or swarm-founding species, where queens do not forage and rarely leave their nests. We asked whether reproductive castes of swarm-founding paper wasps in the tribe Epiponini differed in the relative sizes of their mushroom bodies (MB), a key brain region involved in sensory integration, and in learning and memory. We measured brain-size corrected volumes of the MB dendritic-field neuropils (calyces) and the MB axonal bundles (peducles and lobes) for queens and workers from 16 species of 10 genera of the tribe Epiponini. The subject species spanned much of the epiponine phylogeny, differing in colony size and degree of caste differentiation. Queens had significantly higher relative MB investment than workers, both for the MB in toto and for the MB calyces. The magnitude of queen-worker MB size differences did not covary significantly with body size, but species with larger colonies had stronger caste differences in MB size. A review of caste differences in MB volume across a wide range of social Hymenoptera taxa suggested a positive association of MB investment with social dominance is widespread. Significance statement: Social insect castes (reproducing queens and sterile workers) differ strongly in behavior, particularly in swarm-founding species where queens are largely nest-bound. Caste comparisons are a powerful model for understanding brain/behavior relationships. We measured the relative size of a key insect brain region, the mushroom bodies (MB), in 16 swarm-founding wasp species. MB are involved in sensory integration, and in learning and memory. Queens had relatively larger MB than workers, and the magnitude of the queen-worker differences increased with species average colony size. We suggest the reproductive dominance and social contact of nest-bound queens promotes greater mushroom body investment. [ABSTRACT FROM AUTHOR]

Taxonomic notes are presented on the Polistes stigma species group of the subgenus Polistella Ashmead, 1904, of the genus Polistes Latreille, 1802, in continental Southeast Asia. Three new species are described and illustrated: Polistes brunus Nguyen & Carpenter, new species; P. communalis Nguyen, Vu & Carpenter, new species; and P. tenebris Nguyen & Lee, new species. A key to these species is provided. Their nests are also described. [ABSTRACT FROM AUTHOR]

Additions to the knowledge of the paper wasp genus Polistes (Polistella) (Hymenoptera: Vespidae: Polistinae) from the northern part of Vietnam are presented. The males of two species, P. affinis Gusenleitner, 2006, and P. curcipunctum Nguyen, Kojima & Saito, 2011, are described for the first time. The nests of P. affinis Gusenleitner, 2006, and P. nipponensis Pérez, 1905, are also described. [ABSTRACT FROM AUTHOR]

The observation of two distinct, well-defined oviposition areas in nests of the primitively eusocial wasp Polistes versicolor suggests the presence of multiple egg-layers and territorial behaviors. Electrophoretic analysis of enzyme loci in pupae from 35 colonies revealed an average observed heterozygosity of 0.10 and the existence of private polymorphisms, thereby indicating a low dispersion in this species. No evidence of diploid males was found. Phenotypic segregation analysis revealed the presence of more than one egg-laying female in 15 out of 35 colonies, as well as spatially preferential oviposition in 2 out of 13 nests, with distinct oviposition areas. Genetic relatedness estimates for brood were lower than expected for haplodiploid species under monogynous conditions (r = 0.75 for female broods and r = 0.5 for male) in 4 of those 13 nests, thereby inferring complex sociogenetic structuring in Polistes versicolor colonies.

The aim of this study was to record the parasitoid species found in social wasps nests sampled in different localities in Brazil and investigate the existence of preferential host-parasite associations in different tribes of Neotropical paper wasps. We sampled nests of Mischocyttarus cassununga, Mischocyttarus consimilis, Mischocyttarus imitator, Polistes canadensis, Polistes cinerascens, Polistes versicolor, Angiopolybia pallens, Leipomeles spilogastra, Polybia jurinei and two indeterminate species of Mischocyttarus. M. cassununga, M. imitator and Mischocyttarus (Phi) sp.1 were parasitized by Toechorychus guarapuavus (Ichneumonidae) and M. consimilis, M. imitator and Mischocyttarus sp. 2 was parasitized by Toechorychus fluminensis (Ichneumonidae). P. versicolor and P. cinerascens were parasitized by Elasmus polistes (Eulophidae) and P. canadensis by Simenota depressa (Trigonalidae); A. pallens and L. spilogastra, were infested by Brachymeria sp.1 and Brachymeria sp.2 (Chalcididae), respectively. M. cassununga and Polybia jurinei were parasitized by Megaselia scalaris (Phoridae). We suggested that there may be specific and preferential association between parasitoids and social paper wasps.

Biosynthesis of silver nanoparticles (AgNPs) using nest extract of paper wasp ( Polistes sp) was investigated in this work. The AgNPs were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), and evaluated for antibacterial, antifungal, dye degradation, blood anticoagulation, and blood clot dissolution (thrombolytic) activities. The crystalline polydispersed AgNPs with size range of 12.5-95.55 nm absorbed maximally at 428 nm and showed anisotropic structures of sphere, triangle, hexagon, rod, and rhombus. The FTIR data showed prominent peaks at 3426 and 1641 cm, which indicate the involvement of phenolics compounds and proteins in the synthesis of AgNPs. The prominence of Ag in the EDX spectra showed that indeed, AgNPs were formed. The AgNPs showed potent antibacterial activities (12-35 mm) against three multi-drug strains of Pseudomonas aeruginosa and Klebsiella granulomatis. While the growth of Aspergillus flavus and Aspergillus niger was completely suppressed, the AgNPs produced growth inhibition of 75.61 % against Aspergillus fumigatus at 100 µg/ml. Furthermore, the AgNPs degraded malachite green to the tune of 93.1 %. The AgNPs also prevented coagulation of blood, while it completely dissolved preformed blood clots within 5 min showing the potent anticoagulation and thrombolytic activities. This study, which is the first of its kind to use nest extract of paper wasp for the synthesis of nanoparticles, has shown that the biosynthesized AgNPs could be deployed for biomedical and catalytic applications. [ABSTRACT FROM AUTHOR]

Recent studies have reported incipient morphological caste dimorphism in the Van der Vecht organ size of some temperate Polistes paper wasps. Whether species other than the temperate ones show a similar pattern remains elusive. Here, we have studied some Neotropical Polistes species. By comparing females collected through the year, we showed caste related differences in the size of the Van der Vecht organ in P. ferreri (body size corrected Van der Vech organ size of queens = 0.45 ± 0.06, workers = 0.38 ± 0.07 mm2, p = 0.0021), P. versicolor (body size corrected Van der Vech organ size of queens = 0.54 ± 0.11, workers = 0.46 ± 0.09 mm2, p = 0.010), but not P. simillimus (body size corrected Van der Vech organ size of queens = 0.52 ± 0.05, workers = 0.49 ± 0.06 mm2, p = 0.238). Therefore, it seems that queens and workers of some Neotropical Polistes have diverged in their ontogenic trajectory of the Van der Vecht organ size, providing clear evidence for incipient morphological caste dimorphism. As Polistes are distributed mostly in the tropics, we propose that physical caste differences may be widespread in the genus. Also, we highlight that morphological divergence in the queen–worker phenotypes may have started through differential selection of body structures, like the Van der Vecht organ. [ABSTRACT FROM AUTHOR]

In cooperatively breeding vertebrates, the existence of individuals that help to raise the offspring of non-relatives iswell established, but unrelated helpers are less well known in the social insects. Eusocial insect groups overwhelmingly consist of close relatives, so populations where unrelated helpers are common are intriguing. Here, we focus on Polistes dominula--the best-studied primitively eusocialwasp, and a species in which nesting with non-relatives is not only present but frequent.We address two major questions: why individuals should choose to nest with non-relatives, and why such individuals participate in the costly rearing of unrelated offspring. Polistes dominula foundresses produce more offspring of their own as subordinates than when they nest independently, providing a potential explanation for co-founding by non-relatives. There is some evidence that unrelated subordinates tailor their behaviour towards direct fitness, while the role of recognition errors in generating unrelated co-foundresses is less clear. Remarkably, the remote but potentially highly rewarding chance of inheriting the dominant position appears to strongly influence behaviour, suggesting that primitively eusocial insects may have much more in common with their social vertebrate counterparts than has commonly been thought. [ABSTRACT FROM AUTHOR]

Paper wasps of the family Vespidae exhibit a wide range of social lifestyles, from facultative eusocial groups to highly ritualistic swarm-founding societies. Even so, adult caste flexibility is widespread throughout the eusocial tribes. Thus, a common endocrine mechanism for caste determination and maintenance in paper wasps is expected, with Polistes dominula serving as a model for the study of mechanisms controlling phenotypic plasticity. In P. dominula, juvenile hormone (JH) and ecdysteroids have been shown to have important caste-determining functions, are important for reproductive growth, and correlate with hydrocarbon signals on the cuticle. Yet research on swarm-founding vespids has shown that JH functions are surprisingly labile, begging the question as to how conserved JH functions are within Polistes, a non-swarming genus. Here, we compared the JH and ecdysteroid titers, cuticular hydrocarbon (CHC) profiles, and prospective visual signals of dominance of free-living foundresses from two sympatric and closely related species of Polistes in South Africa, the indigenous Polistes smithii and the invasive P. dominula. In contrast to P. dominula, neither the JH titer nor the CHC profile was linked to dominance or reproduction in P. smithii, and in both species, hemolymph ecdysteroids were essentially absent. Moreover, many of the relationships between hormones, reproduction, dominance, and social signals in P. dominula are in contrast to studies performed on northern hemisphere populations. The divergence of endocrine and chemical profiles within Polistes offers an unforeseen opportunity to study the evolution of proximate mechanisms underlying phenotypic plasticity. [ABSTRACT FROM AUTHOR]

Many animals have ornaments that mediate choice and competition in social and sexual contexts. Individuals with elaborate sexual ornaments typically have higher fitness than those with less elaborate ornaments, but less is known about whether socially selected ornaments are associated with fitness. Here, we test the relationship between fitness and facial patterns that are a socially selected signal of fighting ability in Polistes dominula wasps. We found wasps that signal higher fighting ability have larger nests, are more likely to survive harsh winters, and obtain higher dominance rank than wasps that signal lower fighting ability. In comparison, body weight was not associated with fitness. Larger wasps were dominant over smaller wasps, but showed no difference in nest size or survival. Overall, the positive relationship between wasp facial patterns and fitness indicates that receivers can obtain diverse information about a signaler's phenotypic quality by paying attention to socially selected ornaments. Therefore, there are surprisingly strong parallels between the information conveyed by socially and sexually selected signals. Similar fitness relationships in social and sexually selected signals may be one reason it can be difficult to distinguish the role of social versus sexual selection in ornament evolution. [ABSTRACT FROM AUTHOR]

Ecological constraints on independent breeding are recognised as major drivers of cooperative breeding across diverse lineages. How the prevalence and degree of cooperative breeding relates to ecological variation remains unresolved. Using a large data set of cooperative nesting in Polistes wasps we demonstrate that different aspects of cooperative breeding are likely to be driven by different aspects of climate. Whether or not a species forms cooperative groups is associated with greater short-term temperature fluctuations. In contrast, the number of cooperative foundresses increases in more benign environments with warmer, wetter conditions. The same data set reveals that intraspecific responses to climate variation do not mirror genus-wide trends and instead are highly heterogeneous among species. Collectively these data suggest that the ecological drivers that lead to the origin or loss of cooperation are different from those that influence the extent of its expression within populations. [ABSTRACT FROM AUTHOR]

Laboratory-based animal rearing is a common tool used to control environmental variation. However, important differences between lab and field environments may affect the biological relevance of results. Moreover, how lab rearing affects social dynamics in groups has received little attention. We investigated the effects of lab rearing on gene expression, physiology, behavior, and colony dynamics in a behavioral model system. The primitively eusocial paper wasp Polistes fuscatus has been studied in both lab and field and is an important system for understanding social evolution and caste (queen vs. worker) development. High nourishment has been implicated as a key factor in the development of prequeen ("gyne") traits. Because the nutritional environment is altered in the lab, understanding the effects of lab rearing on caste-related traits is critical to properly interpreting experimental results. Lab-reared wasps have access to ad lib food, whereas field colonies are likely food-limited. Our results support the hypothesis that lab rearing (and associated excess nourishment) biased the development of wasp physiology and to some extent, behavior, toward being more gyne-like. Expression levels of 4 caste-related genes, however, were in the opposite direction, toward more worker-like. Lab rearing also affected colony traits: lab-reared colonies dramatically halted nest construction and began producing male eggs 1 week later than field-reared colonies. These results demonstrate the complex effects of lab-rearing on eco-physiological traits of social species, and we discuss some pros and cons of studying ecological model systems in both lab and field settings. [ABSTRACT FROM AUTHOR]

In many animal species, females are faced with at least 2 reproductive options: independent or cooperative breeding. Some individuals in cooperative groups choose to help in rearing the broods of conspecific females. Through observations of how females of Polistes simillimus Zikán, 1951 (Hymenoptera: Vespidae) started new nests in the field, we investigated whether ecological constraints and the geographic variations explain group formation in this species. The founding of nests was studied between 1996 and 2000 in various localities of 2 states of southeastern Brazil. Weekly observations were carried out on 109 pre-worker nests. We kept track of 40 colonies in Minas Gerais State and 69 in São Paulo State, each started either by a single female or by an association of females. There was a chance that worker production would become numerically similar in both solitary and associative colonies in both states. An increased number of foundresses did not improve the chance of colony success in Minas Gerais State, but it improved this chance in São Paulo State, so that colonies each with 3 or more foundressess were always successful. In colonies in both states, nest cell productivity was higher with a greater number of associated females per nest. Females were able to start building nests alone, being the only reproductive, or 2 or more females could cooperate to found a nest, thus increasing worker production. However, the type of environment chosen to establish the nest (anthropogenic or natural) seemed to influence strongly the choice of the founding strategy. [ABSTRACT FROM AUTHOR]

The distinction between worker and reproductive castes of social insects is receiving increased attention from a developmental rather than adaptive perspective. In the wasp genus Polistes, colonies are founded by one or more females, and the female offspring that emerge in that colony are either non-reproducing workers or future reproductives of the following generation (gynes). A growing number of studies now indicate that workers emerge with activated reproductive physiology, whereas the future reproductive gynes do not. Low nourishment levels for larvae during the worker-rearing phase of the colony cycle and higher nourishment levels for larvae when gynes are reared are now strongly suspected of playing a major role in this difference. Here, we present the results of a laboratory rearing experiment in which Polistes metricus single foundresses were held in environmental conditions with a higher level of control than in any previously published study, and the amount of protein nourishment made available to feed larvae was the only input variable. Three experimental feeding treatments were tested: restricted, unrestricted, and hand-supplemented. Analysis of multiple response variables shows that wasps reared on restricted protein nourishment, which would be the case for wasps reared in field conditions that subsequently become workers, tend toward trait values that characterize active reproductive physiology. Wasps reared on unrestricted and hand-supplemented protein, which replicates higher feeding levels for larvae in field conditions that subsequently become gynes, tend toward trait values that characterize inactive reproductive physiology. Although the experiment was not designed to test for worker behavior per se, our results further implicate activated reproductive physiology as a developmental response to low larval nourishment as a fundamental aspect of worker behavior in Polistes. [ABSTRACT FROM AUTHOR]

Discussions regarding Polistinae biogeography in the last two decades rarely associated current patterns of distribution with environmental changes. This well-known and very diverse group of insects is highly endemic in the Neotropics, but environmental factors influencing the enormous biological diversity in the region are not well established. Exploring evidence on the two main hypotheses concerning the origins and early colonization processes of paper wasps we position in favor of the Gondwanan hypothesis and discuss change-promoter processes in the Neotropics whose effects might have altered the distributions and facilitated the speciation of Polistinae in the region. Furthermore, based on recent advances in biogeography, mostly in the integration of ecological and evolutionary information, we highlight directions for future biogeographical research within the group. [ABSTRACT FROM AUTHOR]

Circadian rhythms in social insects are highly plastic and are modulated by multiple factors. In addition, complex behaviors such as sun-compass orientation and time learning are clearly regulated by the circadian system in these organisms. Despite these unique features of social insect clocks, the mechanisms as well as the functional and evolutionary relevance of these traits remain largely unknown. Here we show a modification of the Drosophila activity monitoring (DAM) system that allowed us to measure locomotor rhythms of the honey bee, Apis mellifera (three variants; gAHB, carnica and caucasica), and two paper wasps (Polistes crinitus and Mischocyttarus phthisicus). A side-by-side comparison of the endogenous period under constant darkness (free-running period) led us to the realization that these social insects exhibit significant deviations from the Earth's 24 h rotational period as well as a large degree of inter-individual variation compared with Drosophila. Experiments at different temperatures, using honey bees as a model, revealed that testing the endogenous rhythm at 35°C, which is the hive's core temperature, results in average periods closer to 24 h compared with 25°C (23.8 h at 35°C versus 22.7 h at 25°C). This finding suggests that the degree of tuning of circadian temperature compensation varies among different organisms. We expect that the commercial availability, cost-effectiveness and integrated nature of this monitoring system will facilitate the growth of the circadian field in these social insects and catalyze our understanding of the mechanisms as well as the functional and evolutionary relevance of circadian rhythms. [ABSTRACT FROM AUTHOR]

We combine multivariate ratio analysis (MRA) of body measurements and analyses of mitochondrial and nuclear data to examine the status of several species of European paper wasps (Polistes Latreille, 1802) closely related to P. gallicus. Our analyses unambiguously reveal the presence of a cryptic species in Europe, as two distinct species can be recognized in what has hitherto been considered Polistes bischoffi Weyrauch, 1937. One species is almost as light coloured as P. gallicus, and is mainly recorded from Southern Europe and Western Asia. The other species is darker and has a more northern distribution in Central Europe. Both species occur syntopically in Switzerland. Given that the lost lectotype of P. bischoffi originated from Sardinia, we selected a female of the southern species as a neotype. The northern species is described as P. helveticus sp. n. here. We also provide a redescription of P. bischoffi rev. stat. and an identification key including three more closely related species, P. biglumis, P. gallicus and P. hellenicus. [ABSTRACT FROM AUTHOR]

Insect social parasites, like other parasites, may benefit from inhibiting their host from reproducing (complete or partial parasitic castration) because they can then exploit more of the host's resources for their own reproduction. In particular, social parasites that kill or expel the host queen need to prevent host workers from reproducing; this is a common worker response to the absence of their queen. Indeed, host workers would benefit from detecting the presence of the parasite and investing in direct and indirect fitness. Studying whether and how social parasites control host worker reproduction can provide information about the degree of integration of the parasite in the host colony and help identify factors regulating workers' reproductive decisions in social insects. We investigated whether the paper wasp social parasite, Polistes sulcifer, suppresses Polistes dominula (host) worker reproduction as efficiently as the dominant host female does in queen-right colonies by comparing worker reproductive efforts in parasitized and non-parasitized (control) colonies. Our results show that 6 weeks after usurpation of their colony by the social parasite, parasitized workers (1) had more developed ovaries than control workers and (2) laid more eggs as soon as the opportunity arose. This reproductive readiness of parasitized workers was not apparent 2 weeks after colony usurpation. This suggests that P. dominula workers have evolved means to react to social parasitism, as occurs in some ants, and that the parasite has only limited control over host reproduction. [ABSTRACT FROM AUTHOR]

Background In social groups, dominant individuals may socially inhibit reproduction of subordinates using aggressive interactions or, in the case of highly eusocial insects, pheromonal communication. It has been hypothesized these two modes of reproductive inhibition utilize conserved pathways. Here, we use a comparative framework to investigate the chemical and genomic underpinnings of reproductive dominance in the primitively eusocial wasp Polistes metricus. Our goals were to first characterize transcriptomic and chemical correlates of reproductive dominance and second, to test whether dominance-associated mechanisms in paper wasps overlapped with aggression or pheromone-related gene expression patterns in other species. To explore whether conserved molecular pathways relate to dominance, we compared wasp transcriptomic data to previous studies of gene expression associated with pheromonal communication and queen-worker differences in honey bees, and aggressive behavior in bees, Drosophila, and mice. Results By examining dominant and subordinate females from queen and worker castes in early and late season colonies, we found that cuticular hydrocarbon profiles and genome-wide patterns of brain gene expression were primarily associated with season/social environment rather than dominance status. In contrast, gene expression patterns in the ovaries were associated primarily with caste and ovary activation. Comparative analyses suggest genes identified as differentially expressed in wasp brains are not related to queen pheromonal communication or caste in bees, but were significantly more likely to be associated with aggression in other insects (bees, flies), and even a mammal (mice). Conclusions This study provides the first comprehensive chemical and molecular analysis of reproductive dominance in paper wasps. We found little evidence for a chemical basis for reproductive dominance in P. metricus, and our transcriptomic analyses suggest that different pathways regulate dominance in paper wasps and pheromone response in bees. Furthermore, there was a substantial impact of season/social environment on gene expression patterns, indicating the important role of external cues in shaping the molecular processes regulating behavior. Interestingly, genes associated with dominance in wasps were also associated with aggressive behavior in bees, solitary insects and mammals. Thus, genes involved in social regulation of reproduction in Polistes may have conserved functions associated with aggression in insects and other taxa. [ABSTRACT FROM AUTHOR]

Various animals build nests with defensive structures to deter predation on offspring. Construction of nest defensive structures can reduce the probability of predation but will involve various costs. Here, we examined both the costs and benefits of the construction of a nest defensive structure in a paper wasp, Polistes chinensis antennalis, and clarify whether the paper wasp changes the level of defensive structures of nests depending on predation risk. A foundress (queen) of the paper wasp starts a colony in spring and maintains her nest alone until the emergence of workers. At this stage, pupae in the nests are sometimes preyed on by conspecifics of other nests. The intruder needs to break the cocoon, which seals the entrance of the cell, to extract the pupa from the cell. Foundresses often apply nest material (pulp) to the surface of cocoons in their nests. We found that pulp on a cocoon increased the time an intruder required to break the cocoon. This result shows that the pulp structure on cocoons helps to prevent predation on pupae. On the other hand, pulp on cocoons involved costs, including time required to collect pulp and being a potential obstacle to the emergence of workers from the cocoon. Additionally, we found that the amount of pulp on cocoons was greater in nests under higher predation risk than nests under lower predation risk. These results suggest that pulp on cocoons is a nest defensive structure, and foundresses adjusted the construction of the defensive structure depending on predation risk. [ABSTRACT FROM AUTHOR]

Seven species of the subgenus Polistella Ashmead of the genus Polistes Latreille including a new species, P. brunetus Nguyen & Kojima, sp. n. described here, are recognized to occur in northeastern Vietnam, the easternmost part of the eastern slope of the Himalayas. A key to these species is provided. Their distributional records are remarked. Nests of P. delhiensis Das & Gupta, P. mandarinus de Saussure and P. brunetus are also described. [ABSTRACT FROM AUTHOR]

Paper wasps negotiate over help using indicators of demand. Animal societies are composed of individuals whose genetic interests are often opposed. We conducted experiments on a cooperative paper wasp which reveal the behavioural rules by which group members settle these conflicts.Recent theory and empirical studies of avian biparental systems suggest that animals resolve conflict over parental care via a process of behavioral negotiation or “rules for responding.” Less is known, however, about whether negotiation over helping effort occurs in cooperatively breeding animal societies or whether behavioral negotiation requires a relatively large brain. In this study, we tested whether negotiation over help occurs in a social insect, the paper wasp Polistes dominulus, by recording individual responses to both observed and experimentally induced foraging returns by other group members. In our experiments, we manipulated food delivery to the nest in 2 ways: 1) by catching departing foragers and giving them larval food to take back to the nest and 2) by giving larval food directly to wasps on the nest, which they then fed to larvae, so increasing food delivery independently of helper effort. We found no evidence from Experiment 1 that helpers adjusted their own foraging effort according to the foraging effort of other group members. However, when food was provided directly to the nest, wasps did respond by reducing their own foraging effort. One interpretation of this result is that paper wasp helpers adjust their helping effort according to the level of offspring need rather than the work rate of other helpers. Negotiation based on indicators of demand rather than work rate is a likely mechanism to resolve conflict over investment in teams where helpers cannot observe each other’s work rate directly, as is commonly the case in insect and vertebrate societies. [ABSTRACT FROM PUBLISHER]