Ingestion of polystyrene microparticles impairs survival and defecation in larvae of Polistes satan (Hymenoptera: Vespidae).

Microplastics (MPs) are widespread pollutants of emerging concern, and the risks associated with their ingestion have been reported in many organisms. Terrestrial environments can be contaminated with MPs, and terrestrial organisms, including arthropods, are predisposed to the risk of ingesting MPs. In the current study, the larvae of the paper wasp Polistes satan were fed two different doses (6 mg or 16 mg at once) of polystyrene MPs (1.43 mm maximum length), and the effects of these treatments on immature development and survival till adult emergence were studied. Ingestion of the two doses resulted in mortality due to impaired defecation prior to pupation. The survival of larvae that ingested 16 mg of MPs was significantly lower than that of the control. The ingestion of 16 mg of MPs also reduced the adult emergence (11.4%) in comparison to the control (44.4%). MPs were not transferred from the larvae to the adults that survived. These findings demonstrate that MP ingestion can be detrimental to P. satan, e.g. larval mortality can decrease colony productivity and thus the worker force, and that MPs can potentially affect natural enemies that occur in crops, such as predatory social wasps.

Natural Areas of Cerrado Foster Wasp (Hymenoptera) Diversity in Human Modified Landscapes.

Land use changes from native vegetation to agriculture, livestock grazing, and urban development are among the main problems related to biodiversity loss worldwide. In this paper we evaluate how land use changes (eucalypt plantation and pasture) affect the richness and assemblage of wasps (Braconidae, Ichneumonidae, Pompilidae, and Vespidae), in comparison with nearby areas with native vegetation in the Cerrado. Specimens were collected at six points, with two Malaise traps at each location. The collections were performed monthly for 10 d, for 12 mo. A total of 773 hymenopterans of the selected groups were collected, representing 253 species or morphospecies. Richness of the families Ichneumonidae and Pompilidae between the areas did not present significant differences. For the families Braconidae and Vespidae, the richness was greater in the eucalypt plantation and pasture areas compared to the native area. Species composition in the native habitat was different from either of the managed habitats in the studied environment. Furthermore, the composition of wasps in native areas varied less throughout the sampling campaigns when compared with the pasture and eucalyptus sites. In native areas, 85 exclusive morphospecies were found. Thus, changes in land use may cause changes in the composition of wasp species, since areas with native vegetation presented more heterogeneous and stable environments than the other land uses. The maintenance of native areas, even if close to planted forest and/or pasture areas, could be the best way to combine forest productivity with biodiversity conservation.

Antiseizure potential of peptides from the venom of social wasp Chartergellus communis against chemically-induced seizures.

Epilepsy is one of the most common neurological diseases in the world. The objective of this research was to investigate a new peptide from the venom of the social wasp Chartergellus communis useful to the study or pharmacotherapy of epilepsy. The wasps were collected, and their venom was extracted. Afterward, the steps of fractionation, sequencing, and identification were carried out to obtain four peptides. These molecules were synthesized for behavioral evaluation tests and electroencephalographic assays to determine their antiseizure potential (induction of acute seizures using the chemical compounds, pentylenetetrazole - PTZ, and pilocarpine - PILO) and analysis of neuropharmacological profile (general spontaneous activity and alteration in motor coordination). Chartergellus-CP1 (i.c.v. - 3.0 µg/animal) caused beneficial alterations in some of the parameters evaluated in both models: PTZ (latency and duration of maximum seizures) and PILO (latency and duration of, and protection against, maximum seizures, and reduction of the median of the seizure scores. When evaluated in 3 doses in the seizure model induced by PILO, the dose of 3.0 µg/animal protected the animals against seizures, with an estimated ED50 of 1.49 µg/animal. Electroencephalographic evaluation of Chartergellus-CP1 showed an improvement in latency, quantity, and percentage of protection against generalized electroencephalographic seizures in the PILO model. Further, Chartergellus-CP1 did not cause adverse effects on general spontaneous activity and motor coordination of animals. This study demonstrated how compounds isolated from wasps' venom may be important resources in the search for new drugs. Such compounds can be considered valuable therapeutic and biotechnological tools for the study and future treatment of epileptic disorders. In this context, a peptide that is potentially useful for epilepsy pharmacotherapy was identified in the venom of C. communis.

Nest-departure behaviour of gynes and drones in the invasive yellowjacket Vespula germanica (Hymenoptera: Vespidae).

Inbreeding costs can be high in haplodiploid hymenopterans due to their particular mechanism of sex determination (i.e., single-locus complementary sex-determination system, sl-CSD), as it can lead to the production of sterile males. Therefore, mechanisms contributing to reduced inbred matings can be beneficial. In this sense, asynchronous nest departure of sibling drones and gynes could reduce kin encounters in social hymenopterans. Using six observation colonies, we determined under field conditions the nest departure behaviour of sibling reproductives of the social wasp Vespula germanica (Hymenoptera: Vespidae). We determined that sexuals leave the nests definitively and detected asynchronous departure not fixed to a particular caste at a seasonal scale in some colonies, as gynes or drones delayed their departure as a function of the departure of the opposite sex, depending on the colony. At a higher temporal resolution (i.e., within a day), we discovered that drones consistently began to leave nests 1 h before gynes and this difference was driven by those individuals that left on the same day as did the opposite-sex kin. Even though other mechanisms such as polyandry and differential dispersal could also be important at reducing inbred matings in the species, the observed departure patterns (i.e., in some colonies actually leave together with the opposite caste, while in others temporal segregation seems to occur) from nests could be complementary to the former and be important at reducing the negative effects of inbreeding in this invasive species.

Faunal analysis and injuries characterization of Polistinae (Hymenoptera, Vespidae) in niagara rosada vineyards in Bento Gonçalves, Rio Grande do Sul state, Brazil / Análise faunística e caracterização de injúrias de Polistinae (Hymenoptera, Vespidae) em parreirais de niagara rosada em Bento Gonçalves, Rio Grande do Sul, Brasil

The State ofRio Grande do Sul is a major producer of grapes in Brazil, highlighting the Serra Gaúcha as the main producing region. In the pursuit of good quality in grapes it is essential the control of pests, especially insects. This study highlights the incidence of wasps, which cause serious damage at harvest time. This study aimed to characterize the community of social wasps (Hymenoptera, Vespidae) through faunal analysis and to examine the relationship of these insects with injuries to the grape berries in vineyards of Bento Gonçalves, Rio Grande do Sul State. Therefore, active search were made in January and February 2014, followed by analysis of frequency, constancy, abundance, dominance and diversity. Ten species of wasps were able to use grape berries as food. The two dominant species were Polybia ignobilis and P. minarum, however, Synoeca cyanea has greater ability to break the intact berries. Other three species, Polistes cavapytiformis, P. versicolor and Brachygastra lecheguana, were also able to break the skin of grapes, but of damaged berries.

O Rio Grande do Sul é o maior produtor de uvas no Brasil, destacando-se a Serra Gaúcha como principal região produtora. Na busca de qualidade das uvas é fundamental o controle de pragas, especialmente insetos. Este trabalho identifica a incidência de vespas que acarretam graves danos na época de colheita. A pesquisa foi conduzida com o objetivo caracterizar a assembleia de vespas sociais (Hymenoptera, Vespidae) através de análise faunística e a relação destas com injúrias as bagas, em parreirais do município de Bento Gonçalves, Rio Grande do Sul. Para tanto, foram realizadas coletas ativas nos meses de janeiro efevereiro de 2014, realizando-se análise de frequência, constância, abundância, dominância e diversidade da comunidade. Foram identificadas 10 espécies de vespas capazes de utilizar as bagas de uva como alimento. As espécies predominantes foram Polybia ignobilis e P. minarum, todavia, Synoeca cyanea apresenta maior capacidade de rompimento de bagas íntegras. P. cavapytiformis, P. versicolor e Brachygastra lecheguanatambém foram capazes de abrir a casca dos frutos em bagas anteriormente danificadas.

Nectarinella manauara, new species and record of the genus from Brazilian Amazonia (Hymenoptera, Vespidae, Polistinae)

ABSTRACT Nectarinella manaura sp. nov. is described, representing the first record of the genus from Brazilian Amazonia. Its description raises richness for Nectarinella from two to three species, and extends the range of characteristics for the genus, especially in terms of body size and color patterns. Discovery of the new species may shed new light into the knowledge of phylogenetic relationships between Nectarinella and other closely related genera.

Evaluation of Thr6-bradykinin purified from Polybia occidentalis wasp venom in the choline uptake of mammal cortices.

CONTEXT: Thr6-bradykinin is a peptide found in the venom of social and solitary wasps. This kinin, along with other bradykinin-like peptides, is known to cause irreversible paralysis in insects by presynaptic blockade of cholinergic transmission. However, this activity has never been tested in mammals. OBJECTIVE: As such, the objective of this study was to evaluate the effect of Thr6-bradykinin on the cholinergic system of rats. MATERIALS AND METHODS: The peptide was isolated from the venom of the Neotropical social wasp Polybia occidentalis Olivier (Vespidae). After correct identification and quantification by ESI-MS and MS/MS, the peptide was tested in [14C]-choline uptake using rat cortical synaptosomes. Each uptake assay was accompanied by lactic acid dehydrogenase (LDH) activity measurement to evaluate synaptosome integrity in the presence of six increasing concentrations of BK or Thr6-BK (0.039, 0.156, 0.625, 2.500, 10.000 and 40.000 µM). RESULTS: Data revealed that neither BK nor Thr6-BK at any of the six concentrations tested (from 0.039 to 40.000 µM) affected [14C]-choline uptake in synaptosomes. Moreover, there was no increase in LDH in the supernatants, indicating that BK and Thr6-BK did not disrupt the synaptosomes. DISCUSSION AND CONCLUSION: In contrast to previous reports for the insect central nervous system (CNS), Thr6-BK had no effect on mammalian cholinergic transmission. Nevertheless, this selectivity for the insect CNS, combined with its irreversible mode of action may be relevant to the discovery of new sources of insecticides and could contribute to understanding the role of kinins in the mammalian CNS.

Nesting substrata, colony success and productivity of the wasp Mischocyttarus cassununga

Nesting substrata, colony success and productivity of the wasp Mischocyttarus cassununga. Colonies of the wasp Mischocyttarus cassununga (von Ihering, 1903) are easily found in urban areas. However, in spite of the massive presence of this species in cities, little is known about its nesting habits, colony success and productivity. The present study aimed at answering the following questions: What are the substrates used for nesting by M. cassununga? What is the main foundation strategy adopted by M. cassununga in urban areas: a solitary female or associative foundation? Is there a relationship between foundation strategies and colony success? Is the total number of cells per nest related to the number of adults produced? The study was conducted in Juiz de Fora, southeastern Brazil, from December 2006 to November 2007. Nesting in man-made substrata seems to be a common strategy in M. cassununga (90.9%), with preference for nest building with a horizontal comb facing north. The colonies were established mainly by groups of foundresses (67.6%), with a success of 84%. The number of brood cells produced per nest was 71.74 ± 45.25 (18-203), and it was positively correlated with the number of adults produced. Hence, we can say that the nests founded by M. cassununga are located mainly in man-made substrata and mostly founded by a group of females. The cell reuse behavior increases the number of adults produced, as it optimizes foraging. These characteristics together with its behavior and nesting habits promote the success of this species in thriving in urban environments.

Morfometria e análise populacional de colônias de Apoica flavissima (Hymenoptera, Vespidae) coletadas na Amazônia brasileira / Morphometric and population analysis of colonies of the Apoica flavissima (Hymenoptera, Vespidae) collected in Brazilian Amazonia

Two colonies of the social wasp Apoica flavissima were collected and analyzed to verify the population and morphometric averages of the individuals. Both colonies were in bushes at 700 mm above the floor, close to forest creeks. The colonies were at the beginning of their development stage and showed a reduced number of individuals, when compared with other studies on this genus. Means of adult parameters were: body length 21,6 mm ; width of thorax 3,8 mm; and width of head, 3,5 mm . Pupae presented these averages: body length 20,05 mm; width of thorax 3,75 mm ; and width of head 3,51 mm. Natural environment must offer good conditions for the development of wasps and their pattern nesting. Thus, high growth rates and different nesting behavior can demonstrate environmental influences on biology of this wasp group.(AU)

Duas colônias da vespa social Apoica flavissima foram coletadas e analisadas quanto aos parâmetros morfométricos e a população residente no ninho. Estas estavam fundadas a cerca de 700 mm do chão, nidificadas em plantas herbáceas, nas proximidades de igarapés. Ambas se encontravam no inicio do seu ciclo biológico e apresentavam um pequeno número de indivíduos, quando comparado com outros trabalhos com este gênero. Os adultos foram mensurados com médias de 21,62 mm de comprimento do corpo; 3,8 mm de largura máxima do tórax e 3,5 mm de largura da cabeça. As pupas apresentaram 20,05 mm de comprimento corpóreo; 3,75 mm de largura máxima do tórax e 3,51 mm de largura da cabeça. Ambientes naturais devem favorecer o crescimento dos indivíduos assim como manter os seus padrões de nidificação. Assim, uma discrepante taxa de crescimento e diferentes hábitos de nidificação, podem indicar a influência do ambiente sobre a biologia deste grupo.(AU)

Morfometria e análise populacional de colônias de Apoica flavissima (Hymenoptera, Vespidae) coletadas na Amazônia brasileira / Morphometric and population analysis of colonies of the Apoica flavissima (Hymenoptera, Vespidae) collected in Brazilian Amazonia

Two colonies of the social wasp Apoica flavissima were collected and analyzed to verify the population and morphometric averages of the individuals. Both colonies were in bushes at 700 mm above the floor, close to forest creeks. The colonies were at the beginning of their development stage and showed a reduced number of individuals, when compared with other studies on this genus. Means of adult parameters were: body length 21,6 mm ; width of thorax 3,8 mm; and width of head, 3,5 mm . Pupae presented these averages: body length 20,05 mm; width of thorax 3,75 mm ; and width of head 3,51 mm. Natural environment must offer good conditions for the development of wasps and their pattern nesting. Thus, high growth rates and different nesting behavior can demonstrate environmental influences on biology of this wasp group.

Duas colônias da vespa social Apoica flavissima foram coletadas e analisadas quanto aos parâmetros morfométricos e a população residente no ninho. Estas estavam fundadas a cerca de 700 mm do chão, nidificadas em plantas herbáceas, nas proximidades de igarapés. Ambas se encontravam no inicio do seu ciclo biológico e apresentavam um pequeno número de indivíduos, quando comparado com outros trabalhos com este gênero. Os adultos foram mensurados com médias de 21,62 mm de comprimento do corpo; 3,8 mm de largura máxima do tórax e 3,5 mm de largura da cabeça. As pupas apresentaram 20,05 mm de comprimento corpóreo; 3,75 mm de largura máxima do tórax e 3,51 mm de largura da cabeça. Ambientes naturais devem favorecer o crescimento dos indivíduos assim como manter os seus padrões de nidificação. Assim, uma discrepante taxa de crescimento e diferentes hábitos de nidificação, podem indicar a influência do ambiente sobre a biologia deste grupo.

Nidification of Polybia rejecta (Hymenoptera: Vespidae) associated to Azteca chartifex (Hymenoptera: Formicidae) in a fragment of Atlantic Forest, in the state of Minas Gerais, southeastern Brazil / Nidificação de Polybia rejecta (Hymenoptera: Vespidae) associada com Azteca chartifex (Hymenoptera: Formicidae) em um fragmento de Mata Atlântica, no estado Minas Gerais, Sudoeste do Brasil

Records to nesting between associated social wasp Polybia rejecta (Fabricius, 1798) and the ant Azteca chartifex Forel, 1896 in the Parque Estadual do Rio Doce, Minas Gerais, are reported. This association is reported for the first time in this biome. Twelve colonies of P. rejecta founded close to nests of A. chartifex were observed. The wasp colonies were founded at a distance of about 10-20 cm from the ant nest and they did not overlap. The nests of wasps were smaller compared to ant, but the coloring was similar protective casing, making it difficult to differentiate between the wasp nest and the ant.

Registra-se a nidificação associada entre a vespa social Polybia rejecta (Fabricius, 1798) e a formiga Azteca chartifex Forel, 1896 no Parque Estadual do Rio Doce, Minas Gerais. Esta associação é observada neste bioma pela primeira vez. Observaram-se doze colônias de P. rejecta fundadas ao lado de ninhos da A. chartifex . Cada colônia da vespa social foi fundada a uma distância em torno de 10 a 20 cm do ninho da formiga, não ocorrendo sobreposição das colônias. Os ninhos das vespas eram menores em relação a formiga, porém a coloração do invólucro protetor era semelhante, o que dificultava a diferenciação entre os ninho da vespa e da formiga.

Analysis of digestive tract content of the larvae of Polybia scutellaris (White) (Hymenoptera, Vespidae) / Análise do conteúdo do trato digestivo das larvas de Polybia scutellaris (White) (Hymenoptera, Vespidae)

Polybia scutellaris (White, 1841) is a social wasp of biological interest for its role as pollinator and maybe as biological control agent of sanitary and agricultural pests. This study examines the digestive tract contents of the larvae of P. scutellaris from four nests in Magdalena (Buenos Aires province, Argentina). Contents included both animal (arthropod parts) and plant (pollen, leaf and fruit epidermis) parts. The pollen content analysis showed that the wasps visited 19 different taxa of plants during the last active period of the colony before the nests had been collected. The range of sources used by P. scutellaris allows us characterizing the species as a generalist flower visitor. Wasps visited both native and exotic plants located nearby the nest. Most of the epidermal plant remains found in the larval digestive tract belonged to Malvaceae, a family not exploited by the studied colonies as pollen source.

Polybia scutellaris (White, 1841) é uma vespa social de interesse biológico devido ao seu papel como polinizador e possível agente de controle biológico de pragas sanitárias e agrícolas. O presente estudo analisou o conteúdo do trato digestivo de larvas de P. scutellaris de quatros ninhos em Magdalena (província de Buenos Aires, Argentina). O conteúdo inclui restos animais (partes de artrópodos) e vegetais (pólen, epiderme de folhas e frutos). A análise do conteúdo polínico mostrou que as vespas visitaram 19 táxons durante o último período ativo da colônia antes dos ninhos serem coletados. A diversidade de recursos utilizados por P. scutellaris permite caracterizá-la como um visitante generalista de flores. As vespas visitaram plantas nativas e exóticas localizados nas proximidades do ninho. A maioria dos restos de epiderme encontradas no trato digestivo das larvas pertence às Malvaceae, uma família não explorada pelas colônias estudadas como fonte de pólen.

Castes and asynchronous colony cycle in Polybia bistriata (Fabricius) (Hymenoptera: Vespidae)

Neotropical swarm-founding wasps, the Epiponini, are an outstanding group of social insects whose societies are polygynic and complex nest builders. Caste dimorphism in these wasps ranges from incipient to highly distinct. Morphometric analyses of nine body parts, ovarian status, relative age and development of the 5th gastral sternite gland (Richards´ gland) of Polybia bistriata Fabricius were undertaken in order to estimate caste differentiation in nine colonies. Morphological and physiological data were used in multivariate analyses in order to evaluate the level of discrimination between inseminated and non-inseminated females. Clear physiological differences were found: queens had highly developed ovaries and they were inseminated, and workers had totally undeveloped ovaries or they had few developed oocytes (only in two colonies), but in both cases insemination was not detected. ANOVA and discriminant function analysis detected slight, but significant differences between castes. In relation to colony cycle, colonies were considered to be in the following stages: one in pre-emergence, four in worker production and four in sexuals production. Richards´ gland analyses indicated that in small colonies (<100 females) queens had a less developed gland than in medium (100-200 females), and large colonies (>200 females). Taking the whole data, it was possible to conclude that caste differences were slight, but more evident in some phases of the colony cycle, a phenomenon previously described for other epiponines.

Os Epiponini, vespas sociais neotropicais, são um grupo de insetos sociais com sociedades poligínicas, construtoras de ninhos complexos. O dimorfismo das castas varia de incipiente até altamente distinto. Análises morfométricas de nove partes corporais, estágio de desenvolvimento ovariano, idade relativa e desenvolvimento da glândula do quinto esternito do gáster (glândula de Richards) de Polybia bistriata (Fabricius) foram utilizados para calcular o nível de diferenciação das castas de nove colônias. Dados morfológicos e fisiológicos foram usados em análises multivariadas para avaliar o nível de discriminação entre fêmeas inseminadas e não-inseminadas. Foram encontradas diferenças fisiológicas claras: rainhas tinham ovários altamente desenvolvidos e inseminados, e as operárias não estavam inseminadas e tinham ovários não desenvolvidos ou uns poucos oócitos desenvolvidos (em duas colônias). ANOVA e análise da função discriminante detectaram diferenças significantes entre as castas. Considerou-se, pelos dados obtidos, que as colônias estavam nas seguintes fases em relação ao ciclo colonial: uma em pré-emergência, quatro em produção de operárias ;.e quatro em produção de sexuados. Análises das glândulas de Richards indicaram o seu menor desenvolvimento em rainhas de colônias pequenas (< 100 fêmeas) do que aquelas de colônias médias (100-200 fêmeas), e grandes (> 200 fêmeas). Considerando-se todos os dados, é possível concluir que as diferenças entre as castas são pequenas, mas evidentes em algumas fases do ciclo colonial, um fenômeno previamente descrito para outros epiponíneos.