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

Abstract

RESUMO -Os Epiponini, vespas sociais neotropicais, são um grupo de insetos sociais com sociedades poligínicas, construtoras de ninhos complexos. O dimorfi smo 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 fi siológicos foram usados em análises multivariadas para avaliar o nível de discriminação entre fêmeas inseminadas e não-inseminadas. Foram encontradas diferenças fi siológicas 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 signifi cantes 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. PALAVRAS-CHAVE: Inseto social, diferenciação de castas, vespa social, morfometria ABSTRACT -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 5 th 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 signifi cant 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...

Linear Alkanes and Reproductive Status of Polistes versicolor (Hymenoptera: Vespidae) Females in Winter Aggregates

“…The ovarian development stage classification was performed according to the developmental degree of ovarioles (adapted from Baio et al, 2004). Ovary type 1: presence of filamentous ovarioles (First stage); ovary type 2: ovarioles slightly swollen and some mature oocytes (Second stage) (Gobbi et al, 2006;Oliveira et al, 2007); ovary type 3: large ovarioles with well developed oocytes (Third stage) (Gobbi et al, 2006).…”

When the predator becomes the prey: record of Mischocyttarus rotundicollis (Cameron, 1912) (Hymenoptera: Vespidae) feeding on a spider in southeastern Brazil

“…However, we provide information that can help us better understand this situation. In your study conducted with Mischocyttarus drewseni de Saussure, 1857 (Hymenoptera: Vespidae), Jeanne (1972) demonstrated, through an experiment, that spiders are consumed by this species when offered mashed, but did not record predatory behavior towards spiders, as it was also not reported in other studies for different species of social wasps that use spiders as a food resource (e.g., Machado et al 1988;Clapperton 1999;Oliveira et al 2010;López et al 2013;Brügger et al 2019). According to Jeanne (1972), there was a record of predation of a spider by Mischocyttarus lecointei (Ducke, 1918) (Hymenoptera: Vespidae), where the wasp captured the arachnid and transported it to a leaf where it consumed it.…”

“…Regarding plantbased foods, wasps can feed on fruit pulp (Brügger et al 2017), floral nectar (Clemente et al 2012), and extrafloral nectar (Oliveira et al 2023a). As for animal-based foods, wasps commonly feed on invertebrates, especially other insects such as Diptera (Gomes et al 2007), Mantodea (Crispim et al 2023), Orthoptera (Garcia et al 2022), Hemiptera (Gobbi & Machado 1985), Blattodea, Dermaptera, Neuroptera (Oliveira et al 2010), beetle larvae (Alves-Silva et al 2013;Alves-Silva & Del-Claro 2016), and Lepidoptera (Prezoto et al 2019;Oliveira et al 2023b;Oliveira & Souza 2023), and even other social wasps (Silveira et al 2016).…”

Nest relocation and high mortality rate in a Neotropical social wasp: Impact of an exceptionally rainy La Niña year

“…For such a common species, relatively little has been published about the biology of P. bistriata. Colonies tend to be small; as summarized by Jeanne [2], ranging from 26-129 adults, but multiple-comb nests contained over 200 adults in Brazil [15], and up to 358 adults in French Guiana (BC, pers. obs.).…”

“…obs.). Colonies are founded by small swarms of older queens and younger workers [15], and the population is small in the ''preemergence'' stage (prior to the emergence of workers). As colonies increase in size during the stage of worker production, queens and workers of all ages occur.…”