Diversidade de vespas sociais (Hymenoptera: Vespidae) em áreas de cerrado na Bahia / Social wasps (Hymenoptera: Vespidae) diversity in a cerrado vegetation in Bahia State, Brazil

A diversidade de espécies de vespas sociais associadas à vegetação de cerrado no Oeste da Bahia foi analisada neste estudo. Dentre as dezenove espécies de vespas sociais encontradas, Chartergus globiventris de Saussure, Chartergellus communis Richards e Metapolybia cingulata (Fabricius) são registradas pela primeira vez para o estado. O cerrado arbóreo, apesar de apresentar maior riqueza (S = 19) e maior diversidade de espécies (H' = 2,33), apresentou níveis de abundância (N = 87 ninhos) inferiores aos sistemas agrícolas (N = 107 ninhos; S = 8 espécies; H' = 1,84). A fisionomia de cerrado campo sujo apresentou a menor abundância de colônias de vespas sociais (N = 61) e valores intermediários de riqueza (S = 13) e diversidade (H' = 2,20).

This study aimed to analyze the social wasps species diversity in a cerrado vegetation at the west region of the State of Bahia. Nineteen species of social wasps were found, with Chartergus globiventris de Saussure, Chartergellus communis Richards and Metapolybia cingulata (Fabricius) being recorded for the first time for the State of Bahia. The arboreous cerrado showed a higher species richness (S = 19) and diversity (H' = 2,33) than the agroecossistems (farms) (S = 8; H' = 1,84). However, nest abundance was higher at the agroecossystems (N = 107 nests) than at the arboreous cerrado (N = 87 nests). The physiognomy of "cerrado campo sujo" showed the lowest abundance of social wasps colonies (N = 61 nests) and intermediate values of species richness (S = 13) and diversity (H' = 2,20).

Morphological caste studies in the neotropical swarm-founding Polistinae wasp Angiopolybia pallens (Lepeletier) (Hymenoptera: Vespidae) / Estudos morfológicos das castas da vespa Polistinae enxameadora neotropical, Angiopolybia pallens (Lepeletier) (Hymenoptera: Vespidae)

Neotropical swarm-founding wasps present polygynic colonies and a great variation in relation to caste differentiation, ranging from species in which queens and workers are similar in shape and size to those where variation in shape and size is conspicuous. Canonical discriminant analysis and Bonferroni t-test analysis on morphometric data collected from eight body parts of specimens from nine colonies of Angiopolybia pallens (Lepeletier) were undertaken as a step towards to a better understanding on caste differenciation in Epiponini. All specimens were dissected to verify the ovary developmental stage, and the spermatheca was removed to check for the mating status. Females were then grouped as queens (mated with developed ovaries), intermediates (virgin with developed ovaries) and workers (virgin with undeveloped ovaries). Even though differences were found for some measurements in seven out of the nine colonies evaluated, multivariate analysis (Wilks' lambda values) indicated castes could not be reliably distinguished only by morphology. We conclude that morphological differences among A. pallens castes are low or absent, reflecting a possible groundplan for the Epiponini, i.e. a post-imaginal pattern of caste differentiation.

As vespas neotropicais enxameadoras possuem colônias poligínicas e uma variação muito grande em relação à diferenciação das castas, desde espécies em que rainhas e operárias possuem formas e tamanhos semelhantes até aquelas em que grande diferença na forma e no tamanho são observados. Estudos morfométricos utilizando oito medidas corporais em nove colônias de Angiopolybia pallens (Lepeletier) foram realizados a fim de aumentar o conhecimento sobre diferenciação de castas em Epiponini, empregando-se análise canônica discriminante e teste t de Bonferroni. Os indivíduos foram dissecados para determinar o nível de desenvolvimento ovariano e as espermatecas foram removidas para verificar a ocorrência de inseminação e assim definir os três grupos de fêmeas: rainhas (ovários desenvolvidos e espermateca fecundada), intermediárias (ovários desenvolvidos e espermateca não-fecundada) e operárias (ovários não-desenvolvidos). Apesar de serem encontradas diferenças significativas para algumas medidas em sete das nove colônias, a análise multivariada (lambda de Wilks) mostrou que as castas são de difícil distinção apenas pela morfologia. É possível concluir que diferenças morfológicas entre castas de A. pallens são pequenas ou ausentes, o que reflete o plano basal para os Epiponini, i.e. padrão pós-imaginal de diferenciação castas.

Morphological caste studies in the neotropical swarm-founding Polistinae wasp Angiopolybia pallens (Lepeletier) (Hymenoptera: Vespidae).

Neotropical swarm-founding wasps present polygynic colonies and a great variation in relation to caste differentiation, ranging from species in which queens and workers are similar in shape and size to those where variation in shape and size is conspicuous. Canonical discriminant analysis and Bonferroni t-test analysis on morphometric data collected from eight body parts of specimens from nine colonies of Angiopolybia pallens (Lepeletier) were undertaken as a step towards to a better understanding on caste differenciation in Epiponini. All specimens were dissected to verify the ovary developmental stage, and the spermatheca was removed to check for the mating status. Females were then grouped as queens (mated with developed ovaries), intermediates (virgin with developed ovaries) and workers (virgin with undeveloped ovaries). Even though differences were found for some measurements in seven out of the nine colonies evaluated, multivariate analysis (Wilks' lambda values) indicated castes could not be reliably distinguished only by morphology. We conclude that morphological differences among A. pallens castes are low or absent, reflecting a possible groundplan for the Epiponini, i.e. a post-imaginal pattern of caste differentiation.

Diversity and community structure of social wasps (Hymenoptera: Vespidae) in three ecosystems in itaparica island, Bahia State, Brazil

We studied the structure and composition of communities of social wasps associated with the three insular ecosystems: mangrove swamp, the Atlantic Rain Forest and the 'restinga'- lowland sandy ecosystems located between the mountain range and the sea. Three hundred and ninety-one nests of 21 social wasp species were collected. The diversity of wasps found in each ecosystem was significantly correlated to the diversity of vegetation in each of the three physiognomies, (r² = 0.85; F(1.16) = 93.85; P < 0. 01). The Tropical Atlantic Forest physiognomy had higher species richness (18 species), followed by the restinga (16 species) and the mangrove (8 species) ecosystems.

A estrutura e a composição de comunidades de vespas sociais associadas a três ecossistemas insulares com fisionomias distintas: Manguezal, Mata Atlântica e Restinga foram analisadas. Foram coletados 391 ninhos de 21 espécies de vespas sociais. A diversidade de vespas encontrada em cada ecossistema está significativamente correlacionada à diversidade de formas de vida vegetal encontrada em cada ambiente estudado (r² = 0,85; F(1.16) = 93,85; P < 0, 01). A floresta tropical Atlântica foi o ecossistema com maior riqueza de vespas (18 espécies), seguida pela Restinga (16 espécies) e pelo Manguezal (8 espécies).