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.

This article analyzes the degree to which scientists at three Mexican higher education institutions ascribe to mainstream scientific protocols and values, as part of a broader analysis of the scientific research environment at those institutions. Specifically, we compared the views of full-time researchers at the Universidad Autónoma del Estado de México (UAEM), with those of their counterparts at the leading universities in the capital, the Universidad Nacional Autónoma de México (UNAM) and the Universidad Autónoma Metropolitana (UAM). In total, we conducted interviews with 270 full-time researchers. The results show a tendency toward humanistic, pedagogical, ethical and socio-curricular approaches, with a range of strategies being employed by different actors.

El artículo diagnostica el potencial científico en tres centros de educación superior, indagando qué tan extendidos están entre los investigadores los acuerdos que rigen la investigación científica. El método consistió en comparar las opiniones que sostienen los investigadores de tiempo completo de la Universidad Autónoma del Estado de México (UAEM), frente a sus similares de la Universidad Nacional Autónoma de México (UNAM) y la Universidad Autónoma Metropolitana (UAM). Para elaborar tal comparación se realizó un trabajo de campo que aglutinó 270 investigadores de tiempo completo de dichas universidades.

This study was performed to determine the degradation and utilization of hemicellulose from intact forages by two strains (P. xylanivorans 2 and P. ruminis 153) isolated from rumen of Creole goats. Fermentations by pure culture were run to completion by using alfalfa hay and native forages selected by goats grazing. Degradation was defined as the solubilization of 80% ethanol-insoluble pentose, whereas utilization was defined as a loss in total pentose. The nutritional components measured from intact forages were cutin, neutral detergent fiber, acid detergent fiber, acid detergent lignin, hemicellulose, cellulose, crude protein and starch. A. lampa showed the maximum degradation value and utilization of hemicellulose, and M. ephedroides and G. decorticans were the native forage species with the smallest value of degradation, in comparison with alfalfa hay. The correlation coefficient between acid detergent lignin and percentage of degradation and utilization of hemicellulose, suggests that lignin affects hemicellulolytic activity of P. xylanivorans. These results provide a framework to try to modify the activity of ruminal hemicellulolytic environment by incorporating P. xylanivorans as probiotic strain.

Este estudio fue desarrollado para determinar la degradación y utilización de la hemicelulosa contenida en diferentes forrajes por dos cepas bacterianas (P. xylanivorans 2 y P. ruminis 153), aisladas del rumen de caprinos Criollos. El cultivo de las cepas puras fue desarrollado hasta evidenciar la fermentación completa del heno de alfalfa y de diversas forrajeras nativas. La degradación fue definida como la solubilización de las pentosas insolubles en etanol al 80%, mientras que la utilización se definió como la pérdida de las pentosas totales. Los componentes nutricionales medidos en los forrajes evaluados fueron: cutina, fibra neutro detergente, fibra ácido detergente, lignina ácido detergente, hemicelulosa, celulosa, proteína cruda y almidón. A. lampa evidenció el máximo valor de degradación y utilización de la hemicelulosa y M. ephedroides y G. decorticans fueron las forrajeras nativas con el menor valor de degradación, en comparación con el heno de alfalfa. El coeficiente de correlación entre el valor de lignina ácido detergente y el porcentaje de degradación y utilización de la hemicelulosa, sugiere que la lignina afecta la actividad hemicelulolítica de P. xylanivorans. Estos resultados proporcionan un marco para intentar modificar la actividad hemicelulolítica del ambiente ruminal, mediante la incorporación de P. xylanivorans como cepa probiótica.

This research explores the scientific culture in Mexico by examining social arrangements that govern the behavior of scientists in their research. It relies on a significant opinion poll, responded by 185 active scientists. In 96% of them report having graduate studies, 76% specify doctorate in one of the natural or social disciplines.

Esta investigación explora la cultura científica en México a través de examinar los acuerdos sociales que norman las conductas de los científicos en sus investigaciones. Se recurre a un significativo sondeo de opinión, el cual responden 185 científicos en activo. En 96% de los casos declaran tener estudios de posgrado, 76% precisan que tienen doctorado en las diversas disciplinas naturales y sociales.

Melipona quadrifasciata quadrifasciata and M. quadrifasciata anthidioides are subspecies of M. quadrifasciata, a stingless bee species common in coastal Brazil. These subspecies are discriminated by the yellow stripe pattern of the abdominal tergites. We found Vsp I restriction patterns in the cytochrome b region closely associated to each subspecies in 155 M. quadrifasciata colonies of different geographical origin. This mitochondrial DNA molecular marker facilitates diagnosis of M. quadrifasciata subspecies matrilines and can be used to establish their natural distribution and identify hybrid colonies.

As abelhas euglossíneas interagem com mais de 60 famílias de plantas da Região Neotropical. Sua riqueza e abundância têm sido intensamente estudadas em diferentes ecossistemas utilizando-se a metodologia de captura de machos em iscas-armadilhas. As fêmeas, entretanto, são pouco conhecidas para a maioria das espécies, e caracteres morfológicos que permitam sua identificação taxonômica não têm sido descritos. O propósito deste trabalho foi utilizar alozimas e padrões de restrição das regiões mitocondriais 16S e Cit b para identificar espécies do gênero Euglossa Latreille. As abelhas foram coletadas enquanto visitavam flores de Thevetia peruviana (Apocynaceae) em cinco cidades do estado de São Paulo. Foram identificadas três espécies de Euglossa entre os 305 indivíduos coletados. Euglossa cordata (L.) foi a única espécie presente em todas as cidades, enquanto E. securigera Dressler e E. townsendi Cockerell foram encontradas em duas e uma cidade, respectivamente. EST-3 mostrou-se ser marcador diagnóstico, enquanto ICD, MDH, ME e PGM foram locos informativos para a identificação de espécies quando considerados conjuntamente. A restrição com VspI da região 16S amplificada, além de diferenciar as três espécies, apresentou polimorfismo intraespecífico para E. cordata e E. securigera. A região Cit b apresentou padrões característicos para E. townsendi, mas não permitiu diferenciar as outras duas espécies. Os resultados descrevem marcadores genéticos potencialmente úteis para a identificação de Euglossa spp. ao nível de espécie e grupo de espécies.

Euglossine bees interact with more than 60 plant families of the Neotropical region. The richness and abundance of these bees have been intensively studied in different ecosystems using the methodology of capturing males with chemical baits. Females are poorly known for most of the species and morphological characters for their taxonomic classification have not yet been described. The purpose of this study was to use allozymes and restriction patterns of the mitochondrial regions 16S and Cyt b to identify species of Euglossa Latreille. Bees were collected while visiting Thevetia peruviana (Apocynaceae) flowers in five cities of the state of São Paulo, Brazil. Three Euglossa species were identified among the 305 individuals collected. Euglossa cordata (L.) was the only species found in all cities, while E. securigera Dressler and E. townsendi Cockerell were restricted to two and one cities respectively. EST-3 was a diagnostic marker, whereas ICD, MDH, ME and PGM were informative for species identification when used in combination. Restriction by VspI of the amplified 16S fragment differentiated the three species and showed intraspecific polymorphism for E. cordata and E. securigera. The Cyt b region showed distinctive patterns for E. townsendi but it was not possible to differentiate the other two species. Our results describe potentially useful genetic markers for the identification of Euglossa spp. at the species and group level.

Heterozygosity and hammuli number asymmetry in adult workers of Apis mellifera (Hymenoptera, Apidae). Relationship between individual heterozygosity at particular loci (Mdh-1, Hk-1 ou Pgm-1) or average heterozygosity of the colony and asymmetry of the hammuli number of right and left wings was verified on adult workers of five Africanized and five European colonies of Apis mellifera. Our results demonstrated the importance of statistical tests to verify the type of asymmetry of the character studied and they did not validate the assumption that uni or multiloci heterozygosity has a positive effect on developmental stability.