Sociogenetic structure of Polistes (Aphanilopterus) versicolor Olivier, 1791 colonies (Hymenoptera, Vespidae, Polistini)

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

Leucine-aminopeptidase A (LAP-A) Encoding Gene in Apoidea: from Genomic Identification to Functional Insights Based on Gene Expression

Aminopeptidases are enzymes that cleave the N-terminal region of proteins and show structural conservation in prokaryotes and eukaryotes. We aimed to identify leucine-aminopeptidase A (LAP-A) orthologs in the genome of bee species with diff erent levels of social organization, and to explore the putative roles of this enzyme based on gene expression data. We identified a single gene for LAP-A on chromosome 15 of Apis mellifera L. and predicted orthologs in genomes of 11 bee species. We found evidence of LAP-A expression in more than 50 bee species. In honeybee and other bees, LAP-A transcripts were expressed in diverse tissues, including: brains, fat bodies, ovaries, testicles, integuments, and glands, on diff erent developmental stages that spanned from embryogenesis to adult life. Our fi ndings on the transcriptional activity of LAP-A are consistent with previously published data on enzymatic activity of LAP-A in bees throughout the development in different tissues and in both sexes. The presence of LAP-A gene in the Apoidea genomes and its ubiquitous expression support housekeeping roles of this enzyme and broad-spectrum functions in bees, independente of their life styles

Nesting Biology, Sexual Dimorphism, and Populational Morphometric Variation in Podium denticulatum F. Smith, 1856 (Hymenoptera: Sphecidae)

Podium denticulatum occurs from Mexico to southern Brazil, including northeastern Argentina. Females use pre-existing cavities to build nests, consisting of cells separated by walls of mud and resin and massively provisioned with paralyzed cockroaches. Trap nests were disposed in three localities in the state of São Paulo, Brazil (Araras, São Carlos, Rifaina), resulting in the collection of 201 nests from December/2003 to June/2007. The founding nests were brought to the laboratory, opened and the pupae transferred to identified vials until the emergence of the adults, when they were then weighed, sexed and stored at -20ºC. The nesting activity was seasonal, with a higher number of nests in the warm and rainy season of the year. The number of constructed cells ranged from one to nine per nest. The emergence rate of adults in the 716 brood cells was 74%, with homogeneous distribution of mortality by egg, larva and pupa stages. This mortality was partly due to parasitism observed in 39% of nests, predominantly by Melittobia sp. and rarely by Diptera (Tachinidae). A 1:1 sex ratio was observed among the newly emerged adults of each locality analyzed. Strong sexual dimorphism was characterized by linear measurements of wings and body mass, with females and males showing a mass between 27-116 mg and 14-70 mg, respectively. The geometric morphometry confirmed this dimorphism and revealed significant variation of wing size and shape among individuals of the analyzed populations, a result that deserves subsequent studies to point out the factors that account for this differentiation

Nesting Substrate Characteristics of Partamona seridoensis Pedro & Camargo (Hymenoptera: Apidae) in Areas of Dry Forest in Brazil

For the first time the association between Partamona seridoensis and Constrictotermes cyphergaster is described. Partamona seridoensis occurs in xeric areas of Northeastern Brazil, and it is a termitophile species as its nests are built in active and inactive arboreal termite nests of the species C. cyphergaster. This study aimed to verify the characteristics of the nesting substrate used by P. seridoensis in two areas of dry forest (caatinga) in Cariri region, Paraíba state. It has been found that the vertical distribution of termites that contained colonies of P. seridoensis varied from 10 cm to 3.60 m, while the height of the nest entrance varied from 20 cm to 3.70 m. Commiphora leptophloeos, popularly known as imburana, was the support tree of 22 (43.1%) from 51 observed termite nests that harbored bee colonies. Most (44; 86.2%) of the host termites colonies were active. Most of the colonies showed the nest entrances not directed to the east/southeast. All colonies located were housed in large termite nests, whose volumes exceed 30 liters. In the two areas surveyed, frequently the entrances of the nests were directed to other nearby colonies, suggesting a parental relationship that should be further investigated

A hierarchical topic modelling approach for tweet clustering

While social media platforms such as Twitter can provide rich and up-to-date information for a wide range of applications, manually digesting such large volumes of data is difficult and costly. Therefore it is important to automatically infer coherent and discriminative topics from tweets. Conventional topic models and document clustering approaches fail to achieve good results due to the noisy and sparse nature of tweets. In this paper, we explore various ways of tackling this challenge and finally propose a two-stage hierarchical topic modelling system that is efficient and effective in alleviating the data sparsity problem. We present an extensive evaluation on two datasets, and report our proposed system achieving the best performance in both document clustering performance and topic coherence

Populational genetic structure and sociogenetic structure of cocoon masses of Digelasinus diversipes (Kirby, 1882) (Hymenoptera: Symphyta: Argidae)

Gene variation and population genetic structure of the Neotropical sawfly Digelasinus diversipes were measured by allozyme analyses using starch gel electrophoresis. Cocoon masses were collected in Eugenia glazioviana (Myrtaceae) stems, in two areas of the "Estação Ecológica Jataí" (Luiz Antônio, SP, Brazil - 21°25' S, 47°50' W), in 2000 and 2001. The average heterozygosity observed in this species (Hobs = 0.094 ± 0.025) was not significantly different from other Symphyta groups; it was, however, significantly higher than in other Hymenoptera populations. No significant levels of inbreeding were found (F IS = 0.062; chi2 = 29.9; p > 0.05), but the population was subdivided (F ST = 0.070; chi2 = 458.9; p < 0.05), suggesting the absence of a significant gene flow among the samples studied, due to limited dispersion ability. The low relatedness coefficients found (ranging from 0.23 ± 0.09 to 0.44 ± 0.10) suggest that larvae from different ovipositions associate to construct the cocoon masses

Gene variation and genetic differentiation among populations of the solitary mud dauber wasp Trypoxylon (Trypargilum) albitarse Fabricius 1804 (Hymenoptera, Crabronidae)

Abstract Trypoxylon is a genus of solitary crabronid wasps whose population genetics is poorly known. The purpose of the present study was to investigate the genetic variation and differentiation among five populations of Trypoxylon albitarse, a species widely distributed throughout the Neotropics, with records from Panama to northern Argentina. Eight species-specific microsatellite loci were used for genotyping 96 adult wasps (one female per nest) sampled at five sites in Brazil. The analysis of allelic richness and private alleles indicated high genetic diversity in the populations sampled. Pairwise comparisons using the Fst and Dest indices revealed significant differentiation for all, but one pair of populations. Fst, Dest, AMOVA and assignment test values pointed to inter-population differentiation. Additionally, the analysis of population structure using Bayesian and PCA methods characterized two alternative genetic groups. The Mantel test indicated no correlation between genetic and geographic distances. Despite evidence of considerable dispersal capacity for T. albitarse, the data indicate low to moderate population structuring in this species

Mortalidade de abelhas visitantes de flores de Caesalpinia peltophoroides Benth (Leguminosae) no estado de São Paulo, Brasil

É relatada a mortalidade de abelhas (213 fêmeas e 60 machos) pertencentes a 20 espécies ao visitarem as inflorescências de Caesalpinia peltophoroides. A presença presumida de um composto tóxico no néctar mostrou grande variação espacial e temporal. Árvores individuais produziram ou não mortalidade de abelhas em diferentes períodos de floração e árvores vizinhas mostraram efeitos distintos em cada floração. A toxicidade sobre as abelhas foi igualmente variável. A maior parte das abelhas morria logo após visitarem as flores; algumas mostravam sinais de narcose, morrendo em seguida; poucas, após um período de narcose, deixaram este estado e voaram. Utilizando o índice de desgaste alar foram observadas abelhas jovens (29%), velhas (26%) e de idade intermediária (45%) (n = 227) entre as abelhas mortas. Se a presença do presumido composto tóxico afeta ou não o fitness da planta requer inicialmente a identificação de qual(is) fator(es) elicia(m) seu aparecimento. Uma vez que C. peltophoroides é amplamente utilizada em projetos paisagísticos urbanos, é necessário estimar o potencial efeito negativo sobre as comunidades de abelhas que vivem em áreas urbanas de diferentes regiões do Brasil. Até que este efeito seja conhecido, recomenda-se aos profissionais do planejamento urbano a não utilização paisagística da sibipiruna em nossas cidades