Antioxidative Propolis From Stingless Bees (Heterotrigona Itama) Preserves Endothelium-Dependent Aortic Relaxation of Diabetic Rats: The Role of Nitric Oxide and Cyclic Guanosine Monophosphate

Propolis from stingless bees (Heterotrigona itama) is a resinous compound that exhibits antihyperglycaemia, free radical scavenging, and cardioprotective properties. The effect of propolis on diabetic vessels has not been investigated. Thus, this research aimed to determine the effect of propolis supplementation on the level of antioxidants and its mechanism of action in the aorta of diabetic rats. Male Sprague-Dawley rats were divided into five groups (n=8/group): healthy (control), untreated diabetes (DM), metformin-treated diabetes (DM+M, 300 mg/kg/day metformin), propolis-treated diabetes (DM+P, 300 mg/kg/day propolis extract) and diabetes with combined treatment (DM+M+P, dosage as former). Oral supplementation was conducted for four weeks immediately upon successful induction of diabetes by streptozotocin (60 mg/kg, intraperitoneal injection). At the end of the study, the rats were euthanised, and thoracic aorta was processed into tissue homogenates to determine the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase-1 (GPx-1) and soluble receptor for advanced glycation end-products (sRAGE). Aorta segments were harvested to examine their relaxation response towards graded concentration of acetylcholine (Ach; 10-8-10-4) M following precontraction with phenylephrine (PE; 10-6 M). Vasorelaxation towards a cumulative dose of propolis (0.01-1.00%) using PE-precontracted healthy aorta (n=6/experiments) was investigated under various simulated conditions: physiological buffer, L-NAME (10-4 M), methylene blue (10-5 M), indomethacin (10-5 M) and elevated glucose (25 mM). Propolis maintained antioxidative enzymes and sRAGE decoy molecules in the aortic tissue of the diabetic rats. The amelioration of diabetes-induced impairment of endothelium-dependent relaxation by propolis was mediated through the nitric oxide(NO)-cyclic guanosine monophosphate (cGMP) pathway. This non-clinical study reports vasoprotective property of propolis in diabetes mellitus.

Pollen resources partitioning of stingless bees (Hymenoptera: Apidae) from the southern Atlantic forest

Meliponinae eusocial bees are among the most important pollinators in the Neotropics and their beekeeping has been growing as both recreational and economic activity. Information on the pollen preferences and niche overlap among species coexisting in the same location is still scarce. This study focused on the use of pollen resources by three native species of Meliponinae in the Atlantic Forest, Melipona quadrifasciata quadrifasciata (Lepeletier 1836), Scaptotrigona depilis (Moure 1942), and Tetragonisca angustula (Latreille 1811), at two different sites. The use of pollen resources was evaluated from reserves inside hives collected monthly between February 2015 and January 2016. It was also estimated the Mean Minimal Distance (Dm) traveled by the bees to obtain pollen. The bees differed regarding the diversity of pollen types, Dm, and proportion of pollen from different plant life-form. Local factor promoted differences only for Dm. M. q. quadrifasciata foraged a low diversity of pollen species and traveled greater distances with a higher proportion of trees plus palm species. Tetragonisca angustula foraged a higher diversity of pollen and flew shorter distances with a lower proportion of trees and palms. The species factor predominates over the local factor in the clustering pattern, based on pollen profile similarity.

Development of antennal sensilla of Tetragonisca angustula Latreille, 1811 (Hymenoptera: Meliponini) during pupation / Desenvolvimento das sensilas antenais de Tetragonisca angustula latreille, 1811 (Hymenoptera: Meliponini) durante a pupação

Abstract The antennal sensilla are sensory organs formed by a group of neurons and accessory cells, which allow perception of environmental cues, which play a role as mechanoreceptors and chemoreceptors. This study describes the post-embryonic development of the antennal sensilla of the stingless Tetragonisca angustula (Hymenoptera: Meliponini) workers. The development of the antennal sensilla begins in the transition stage of the pre-pupae to white-eyed pupae. The sensilla are completely developed at the black-eyed pupae stage, but they are covered by the old cuticle. The sensilla are exposed to the environment only in newly emerged workers of T. angustula, but it is possible that environmental stimuli can be recognized due to the pores in the old cuticle.

Resumo As sensilas antenais são órgãos sensoriais formados por um conjunto de neurônios que captam estímulos ambientais e células acessórias, desempenhando as funções de mecanorreceptores e quimiorrecepterores. Este trabalho descreve o desenvolvimento pós-embrionário das sensilas antenais de operárias das abelhas sem ferrão Tetragonisca angustula (Hymenoptera: Meliponini). O desenvolvimento das sensilas tem início na transição de pré-pupa para pupa de olho branco e estão completamente desenvolvidas no estágio de pupa de olho preto, mas ainda estão cobertas pela cutícula velha. As sensilas estão completamente expostas em operárias recém-emergidas de T. angustula, mas é possível que estímulos ambientais sejam percebidos em estágios anteriores devido aos poros presentes na cutícula velha.

Distância de voo para forrageamento da abelha uruçu beiço (Melipona eburnea Friese, 1900) / Foraging flight distance for Melipona eburnea Friese bees / Distancia de vuelo para forrajeo de abeja real (Melipona eburnea Friese, 1900)

Devido à necessidade de insumos para manutenção da colônia, as abelhas operárias realizam voos afim de coletar alimentos (pólen e néctar), materiais de construção (barro, resina etc.) e retirar o lixo do interior da colônia. Para realização do experimento foram capturadas 30 abelhas operárias, na saída do ninho, que foram marcadas no tórax com tinta atóxica e colocadas em uma caixa plástica, medindo 11cm de altura por 15cm de largura e 20cm de comprimento. As cores utilizadas na identificação das abelhas foram administradas de acordo com a distância de soltura. Adotaram-se as cores: laranja para 500m; azul para 1.000m; amarela para 1.500m; verde para 2.000m; branca para 1.600m e vermelha para 1.700m. As solturas foram realizadas uma a cada dia de experimento, sendo as distâncias medidas com o auxílio de GPS. As liberações ocorreram entre 07h e 08h da manhã, em linha reta, em relação à colônia. Para contagem do número de abelhas que retornavam, a entrada do ninho foi fechada e, a cada abelha que regressava, era reaberta, permitindo que a mesma entrasse. Para análise dos dados, utilizou-se o programa Microsoft Excel 2013. Houve uma taxa significativa de retorno até 1.500m. A partir dessa distância, o sucesso das atividades de forrageamento foi inferior a 50%, tornando-se inviável a realização de coletas, devido à perda de grande número de forrageiras. As análises mostraram que Melipona eburnea alcança um raio de ação em torno de 908 ha, podendo percorrer uma distância de, aproximadamente, 1.700m em relação ao ninho.(AU)

Due to the need for inputs to maintain the colony, worker bees fly to collect food (pollen and nectar), building material (clay, resin, etc.) and remove garbage from the inside of the hive. In order to carry out this experiment, a total of 30 foraging bees were collected at the exit of the hive, marked on the chest with nontoxic paint and placed in a plastic box measuring 11-cm high, 15-cm wide and 20-cm long. The colors used for the identification of the bees were administered according to the distance of their release. The following colors were adopted: orange for 500 m; blue for 1,000 m; yellow for 1,500 m; green for 2,000 m; white for 1,600 m, and red for 1,700 m. The releases were performed one per day of the experiment, and the distances measured with the aid of a GPS device. The releases took place between 7 and 8 a.m. in a straight line in relation to the hive. In order to count the number of returning bees, the nest entrance was closed and only reopened for each returning bee, allowing it to enter. Data was analyzed used Microsoft Excel 2013. There was a significant rate of return up to 1,500 m. Beyond that distance, the success of foraging activities was less than 50%, making data collection impossible due to the loss of large number of worker bees. The analyzes showed that Melipona eburnea reaches an action radius of around 908 ha, being able to cover a distance of approximately 1,700 m in relation to the hive.(AU)

Debido a la necesidad de insumos para el mantenimiento de la colonia, las abejas obreras realizan vuelos para recolectar alimentos (polen y néctar), materiales de construcción (arcilla, resina, etc.) y quitar la basura desde el interior de la colonia. Para realizar el experimento fueron capturados 30 obreras a la salida del nido, que estaban marcadas en el pecho con tinta no tóxica y puestas en una caja de plástico, midiendo 11cm de alto, 15cm de ancho y 20 cm de longitud. Los colores utilizados en la identificación de las abejas fueron manejados de acuerdo con la distancia de soltura. Se adoptaron los colores: naranja de 500m; azul para 1.000m; amarillo para 1.500m; verde para 2.000m; blanco para 1.600m y rojo para 1.700m. Las solturas se realizaron una a cada día del experimento, y las distancias medidas con la ayuda de un GPS. Las liberaciones ocurrieron entre las 07h y 08h de la mañana, en línea recta, en relación con la colonia. Para conteo del número de abejas que retornaban, la entrada del nido fue cerrada y, a cada abeja que regresaba era reabierta, permitiendo que la misma entrase. Para análisis de los datos se utilizó el programa Microsoft Excel 2013. Hubo una tasa significativa de retorno hasta 1.500m. A partir de esta distancia, el éxito de las actividades de forrajeo fue inferior al 50%, lo que hace inviable la realización de recolecciones, debido a la pérdida de un gran número de forrajes. El análisis mostró que Melipona eburnea alcanza un radio de acción alrededor de 908ha, pudiendo recorrer una distancia de, aproximadamente, 1.700m en relación al nido.(AU)

Morphometric differences and fluctuating asymmetry in Melipona subnitida Ducke 1910 (Hymenoptera: Apidae) in different types of housing / Diferenças morfométricas e assimetria flutuante em Melipona subnitida Ducke 1910 (Hymenoptera: Apidae) em diferentes tipos de habitação

Abstract A geometric morphometrics approach was applied to evaluate differences in forewing patterns of the Jandaira bee (Melipona subnitida Ducke). For this, we studied the presence of fluctuating asymmetry (FA) in forewing shape and size of colonies kept in either rational hive boxes or natural tree trunks. We detected significant FA for wing size as well as wing shape independent of the type of housing (rational box or tree trunks), indicating the overall presence of stress during the development of the studied specimens. FA was also significant (p < 0.01) between rational boxes, possibly related to the use of various models of rational boxes used for keeping stingless bees. In addition, a Principal Component Analysis indicated morphometric variation between bee colonies kept in either rational hive boxes or in tree trunks, that may be related to the different origins of the bees: tree trunk colonies were relocated natural colonies while rational box colonies originated from multiplying other colonies. We conclude that adequate measures should be taken to reduce the amount of stress during bee handling by using standard models of rational boxes that cause the least disruption.

Resumo A abordagem da morfometria geométrica foi aplicada para avaliar as diferenças nos padrões das asas anteriores da abelha Jandaíra (Melipona subnitida Ducke). Para isso, estudou-se a presença de assimetria flutuante (AF) na forma das asas anteriores e tamanho das colônias mantidas tanto em caixas de colméia racional ou troncos de árvores naturais. Foi detectado AF significativa para o tamanho da asa, bem como a forma da asa independente do tipo de habitação (caixa racional ou cortiço), indicando a presença global de estresse durante o desenvolvimento dos espécimes estudados. AF também foi significativa (p < 0,01) entre as caixas racionais, possivelmente relacionados com a utilização de vários modelos de caixas racionais utilizados para a conservação de abelhas sem ferrão. Além disso, a Análise de Componentes Principais indicou variações morfométricas entre as colônias de abelhas mantidos em caixas racionais ou em cortiços, que podem estar relacionados com as diferentes origens das abelhas: os cortiços foram colônias naturais realocados, enquanto as colônias das caixas racionais foram originadas da multiplicação outras colônias. Conclui-se que devem ser tomadas medidas adequadas para reduzir a quantidade de estresse durante o manuseio abelha usando modelos padrão de caixas racionais que causam a menor perturbação.

Fluctuating asymmetry in Apis mellifera(Hymenoptera: Apidae) as bioindicator of anthropogenic environments / Asimetría fluctuante en Apis mellifera (Hymenop-tera: Apidae) como bioindicador de ambientes antropo-génicos

The successful distribution of A. melliferais due to their ability to adjust to seasonal variations, considerable control over their internal physical environment and exploration of different resources. However, their populations have experienced different forms and levels of environmental pressure. This research aimed to verify the phenotypic plasticity in both size and shape of wings in A. melliferausing fluctuating asymmetry, based on geometric morphometrics from apiaries located in sites with high and low levels of anthropization. We sampled 16 locations throughout all five geographic regions of Brazil. At each site, samples were collected from 20 beehives installed in apiaries: 10 installed near high anthropogenic environments (Cassilàndia - MS, Fortaleza - CE, Maringá - PR, Aquidauana - MS, Rolim de Moura - RO, Riachuelo - SE, Ubirata - PR and Piracicaba - SP), and 10 in sites with low levels of human disturbance (Cassilàndia - MS, Itapiúna CE, Uniao da Vitoria - PR, Aquidauana - MS, Rolim de Moura - RO, Pacatuba - SE, Erval Seco - RS, Rio Claro - SP). A sample of 10 individuals was taken in each hive, totaling 200 per location, for a total of 1 600 individuals. We used fluctuating asymmetry (FA) in size and shape of the forewing through geometric morphometrics. The FA analysis was conducted in order to check bilateral differences. The indexes of size and shape were submitted to analysis of variance (ANOVA), where the characters evaluated were used as factors to verify the size and shape differences. The results indicated an asymmetry on the shape of the wing (P < 0.001) but no asymmetry was observed on wing size. Considering FA as an environmental response and high and low impacted areas as a fixed factor, we observed significant differences (P < 0.05). The results for the wing shape in A. melliferademonstrated that this feature undergoes more variation during ontogeny compared to the variation in size. We concluded that bee samples collected from colonies with higher levels of human disturbance had higher wing-shape asymmetry; the variation of fluctuating asymmetry in the wing shape of honeybees can be used as an indicator of the degree of environmental anthropization.

La distribución exitosa de A. melliferase debe a su capacidad para adaptarse a las variaciones estacionales, controlar considerablemente su ambiente físico interno y por la exploración de recursos. Sin embargo, sus poblaciones experimentan diferentes formas y niveles de presión ambiental. Esta investigación evaluó colmenares, ubicadas en entornos con distintos niveles de antropización. Ambientes considerados altamente antropogénicos fueron escogidos: áreas urbanas, agrícolas con aplicaciones de insecticidas, y las industrias con grandes áreas (regiones con altos índices de contaminación). Por otra parte, los entornos considerados con bajos niveles de perturbación humana fueron elegidos: áreas de preservación permanente de los bosques restantes (Mata Atlántica, Planalto, Cerrado), áreas ribereñas o reservas ecológicas. Se muestrearon 16 localidades que abarcan las cinco regiones del Brasil. Estamos utilizando la asimetría fluctuante desde el tamaño y la forma del ala anterior por técnicas de morfometría geométrica. En cada sitio, las muestras se obtuvieron de las 20 colmenas instaladas en los colmenares: 10 instalados cerca de entornos altamente antropogénicos (Cassilándia - MS, Fortaleza - CE, Maringá - PR, Aquidauana - MS, Rolim de Moura - RO, Riachuelo - SE, Ubirata - PR y Piracicaba - SP) y 10 en sitios de bajo nivel de perturbación humana (Cassilándia - MS, ItapiúnaCE, Uniao da Vitória - PR, Aquidauana - MS, Rolim de Moura - RO, Pacatuba- SE, Erval Seco - RS, Rio Claro - SP). Los índices de tamaño y forma fueron sometidos a análisis de varianza (ANOVA), donde se utilizaron los caracteres evaluados como factores, para verificar las diferencias de tamaño y forma. La asimetría de análisis fluctuante (AF) se llevó a cabo con el fin de comprobar las diferencias bilaterales. Los resultados indican la existencia de la asimetría de la forma del ala (P < 0.001), pero no se observó asimetría del tamaño del ala. Considerando AF como respuesta ambiental y áreas de alto y bajo grado de alteración humana como factor fijo, observamos diferencias significativas (P < 0.05). Los resultados, para la forma de ala de la A. mellifera,muestran que esta característica se somete a más variación durante la ontogenia en comparación con la variación en el tamaño. Llegamos a la conclusión de que las colonias de abejas recogidas en ambientes con niveles más altos de la perturbación humana tienen una mayor asimetría en forma de ala, por lo que la asimetría fluctuante en forma de alas de las abejas puede ser utilizada como un indicador del grado de antropización del medio ambiente.

Conforto térmico em colônias de Tetragonisca weyrauchi no município de Rio Branco-Acre / Thermal comfort in Tetragonisca weyrauchi colony the municipality of Rio Branco-Acre / Confort térmico en colonias de Tetragonisca weyrauchi en el municipio de Rio Branco, Acre

A espécie Tetragonisca weyrauchi é capaz de manter a temperatura interna do ninho em homeostase, variando entre 29 e 35 °C, embora ainda não se conheçam os mecanismos usados por esse grupo de insetos para manter o controle da temperatura interna da colônia.O controle termorregulatório no interior da colônia pode ser importante para incubação da cria e para sobrevivência da colmeia, em temperaturas extremas. Para o monitoramento das temperaturas utilizou-se Data Logger (modelo HOBO U12 ­ 012 com exatidão de ±0,35 °C e sensor para medição interna). A temperatura interna foi obtida com sensor Data Logger, introduzido na região dos favos de cria, por meio de um furo na lateral do ninho; já a temperatura externa foi obtida com Data Logger, mantido a 10cm da colmeia. Para verificar a existência do controle termorregulatório da colônia, a temperatura externa foi comparada com a temperatura interna, utilizando-se a correlação de Pearson (R2= 0,514; n= 1159; p<0,05) para determinar os parâmetros de correlação entre as variáveis.O presente estudo demonstrou que existe controle termorregulatório no interior do ninho de T. weyrauchi, que apresentou pouca variação em relação à temperatura externa, ficando em 5,7 °C entre a temperatura mínima e a máxima, no decorrer da investigação.

The Tetragonisca weyrauchi species is able to maintain the internal temperature of the nest in homeostasis, ranging between 29 and 35 °C, although it is not known yet the mechanisms used by this group of insects to maintain control of the internal temperature of the colony. The thermoregulatory control within the colony may be important for establishing incubation and hive survival in extreme temperatures. For monitoring temperatures was used Data Logger (model HOBO U12 - 012 with accuracy of ± 0.35 °C and sensor for internal measurement). The internal temperature was obtained with the sensor (Data Logger) introduced in the region of the combs through a hole beside the nest, also the external temperature was obtained with data logger held 10cm from the hive. To check the existence of thermoregulatory control of the colony, the external temperature was compared with the internal temperature using thePearson correlation(R2= 0,514; n= 1159; p<0,05) to determine the parameters of correlation between the variables. This study .demonstrated that there is thermoregulatory control inside the nest T. weyrauchi that showed a little change from the outside temperature, remaining at 5.7 ° C between the minimum and the maximum temperature during the investigation.

La especie Tetragonisca weyrauchi es capaz de mantener la temperatura interna del nido en homeostasis, que oscilan entre 29 y 35 °C, aunque todavía no conocemos los mecanismos utilizados por ese grupo de insectos para mantener el control de la temperatura interior de la colonia. El control termorregulador dentro de la colonia puede ser importante para eclosión de la cría y para supervivencia de la colmena, en temperaturas extremas. Para el control de las temperaturas se ha utilizado Data Logger (modelo HOBO U12 - 012 con precisión de ±0,35 °C y sensor para medición interna). La temperatura interna se obtuvo con el sensor Data Logger introducido en la región de los panales de cría, a través de un agujero en la lateral del nido; ya la temperatura externa ha sido obtenida con Data Logger, mantenido a 10cm de distancia de la colmena. Para comprobar la existencia del control termorregulador de la colonia, la temperatura externa ha sido comparada con la temperatura interna, utilizándose la correlación de Pearson (R2= 0,514; n= 1159; p<0,05) para determinar los parámetros de correlación entre las variables. El presente estudio ha demostrado que existe control termorregulador en el interior del nido de T. weyrauchi, que mostró poca variación en relación a la temperatura externa, quedando en 5,7 °C entre la temperatura mínima y la máxima, en el curso de la investigación.

Las abejas (Hymenoptera: Apoidea) del Parque Nacional Natural Gorgona, Pacífico colombiano / Bees (Hymenoptera: Apoidea) of the Gorgona National Natural Park, Colombian Pacific

Bees (Hymenoptera: Apoidea) of Gorgona Natural National Park, Colombian Pacific. The National Natural Park Gorgona is a continental island off the Colombian Pacific coast. Bees have a specialized and crucial role in this isolated and unique ecosystem and here we assess their biodiversity. In three visits, at intervals of three months, six areas of the island with variable vegetation cover, were sampled. Sampling was done indirectly using (i) McPhail traps (baited with cineole, methyl silicate and clove oil), (ii) Van Someren Rydon traps (baited with rotting fish, chicken or fruit), (iii) Malaise traps and (iv) light traps. In addition, a direct sampling was carried out along transects of indeterminate length, for periods of one hour in each area and repeated four times. A total of 585 specimens was captured, of these 443 belong to Apidae (14 genera), 141 to Halictidae (six genera) and one Megachilidae. With this report the local inventory of bees rises to 43 species and 28 genera. Trigona fulviventris guianae Cockerell, 1910 was the most abundant species, Euglossa ignita, the most attracted to aromatic lures and Megalopta genalis Meade-Waldo, 1916 was the dominant species during evening hours. The absence of Apis mellifera was noticeable. Rev. Biol. Trop. 62 (Suppl. 1): 297-305. Epub 2014 February 01.

En este estudio se presenta la diversidad y abundancia de las abejas del PNN Gorgona. En tres visitas en intervalos de tres meses, se muestrearon seis zonas de la isla con cubierta vegetal variable. Los muestreos fueron indirectos usando (i) trampas McPhail (cebadas con cineol, silicato de metilo y extracto clavos); (ii) trampas Van Someren Rydon (con cebo de pescado o pollo o fruta podridos), (iii) trampas Malaise y (iv) trampas de luz y directos a lo largo de transectos de longitud indefinida, por períodos de una hora en cada área y se repitieron cuatro veces. Un total de 585 especímenes fueron capturados, de ellos, 443 pertenecen a Apidae (14 géneros), 141 a Halictidae (seis géneros) y uno a Megachilidae. Con este informe, el inventario local de Abejas se eleva a 43 especies y 28 géneros. Trigona fulviventris guianae Cockerell, 1910 fue la especie más abundante, Euglossa ignita Smith, 1874 la más atraída por los cebos aromáticos y Megalopta genalis Smith, 1853 dominó durante la noche. Apis mellifera Linnaeus, 1758 no se encontró en los muestreos. La importancia de la Isla Gorgona, como sitio de la diversidad para las especies de abejas es discutida.

Size and shape in Melipona quadrifasciata anthidioides Lepeletier, 1836 (Hymenoptera; Meliponini) / Tamanho e forma em Melipona quadrifasciata anthidioides Lepeletier, 1836 (Hymenoptera; Meliponini)

This study aimed to identify differences in wing shape among populations of Melipona quadrifasciata anthidioides obtained in 23 locations in the semi-arid region of Bahia state (Brazil). Analysis of the Procrustes distances among mean wing shapes indicated that population structure did not determine shape variation. Instead, populations were structured geographically according to wing size. The Partial Mantel Test between morphometric (shape and size) distance matrices and altitude, taking geographic distances into account, was used for a more detailed understanding of size and shape determinants. A partial Mantel test between morphometris (shape and size) variation and altitude, taking geographic distances into account, revealed that size (but not shape) is largely influenced by altitude (r = 0.54 p 0.01). These results indicate greater evolutionary constraints for the shape variation, which must be directly associated with aerodynamic issues in this structure. The size, however, indicates that the bees tend to have larger wings in populations located at higher altitudes.

Este trabalho avaliou a divergência de forma entre populações de Melipona quadrifasciata anthidioides, utilizando caracteres morfométricos em 23 localidades da região semi-árida do estado da Bahia (Brasil). As análises das distâncias de Procrustes entre as formas médias das asas indicaram que não há estruturação populacional para a variação dessa estrutura. Entretanto, nossas análises demonstraram que as populações estavam estruturadas geograficamente pelo tamanho das asas. O teste parcial de Mantel entre matrizes de distâncias morfométricas (forma e tamanho) e altitude, levando em conta as distâncias geográficas, foi utilizado para uma compreensão mais detalhada dos determinantes de tamanho e forma. O teste de Mantel entre as variações morfométricas (forma e tamanho) e altitude, tendo em conta as distâncias geográficas, revelou que o tamanho (mas não a forma) é amplamente influenciado pela altitude (r = 0,54 p 0,01). Tais resultados indicam maiores restrições evolutivas para a variação de forma, o que deve estar diretamente associado às questões aerodinâmicas dessa estrutura. O tamanho, por outro lado, indica que as abelhas estudadas tendem a apresentar asas maiores nas populações localizadas em regiões de maior altitude.

Morphometry of the midgut of Melipona quadrifasciata anthidioides (Lepeletier) (Hymenoptera: Apidae) during metamorphosis

In Hymenoptera, midgut changes begin in the last instar. At this stage, the larval epithelial digestive cells degenerate, leaving only the basal membrane and the regenerative cells which will develop into a new epithelium during the pupal stage and in the adult. Epithelium renewal is followed by changes in volume and shape of the midgut. Morphometric analysis of digestive cells and total midgut volume of Melipona quadrifasciata anthidioides (Lepeletier) were conducted to verify whether cell volume increase are sufficient to account for the total midgut volume increase that occurs during metamorphosis. An increase in midgut volume was verified in spite of the scarcity of cell proliferation found during metamorphosis. At the end of metamorphosis, the increase in cell volume was not sufficient to explain the increase in volume of the midgut, indicating that an increase in the number of digestive cells is apparently necessary. Nevertheless, the mechanism by which regenerative cells reconstitute the epithelium during metamorphosis remains unknown.

Proboscis Length and Resource Utilization in Two Uruguayan Bumblebees: Bombus atratus Franklin and Bombus bellicosus Smith (Hymenoptera: Apidae)

Bumblebees (Bombus sp.) are eusocial insects with an annual life cycle whose use as pollinator of crops has gained great importance in modern agriculture. Several authors have found that resource use in Bombus species is usually based on the correlation between the proboscis length of the bumblebees and the corolla depth of the flowers. The aim of this study was to determine proboscis length of Bombus atratus and B. bellicosus, two Uruguayan bumblebees, and verify the resource exploitation testing two cultivated species, the red clover and the bird's foot trefoil. Bumblebee foraging activity was recorded in two culture conditions: in a red clover and bird's foot trefoil mixed meadow, and in contiguous plots of these legumes, and the proboscis length of collected foragers was determined. Both species of bumblebees exploited red clover and bird's foot trefoil although they did it in different proportions in all instances tested. The results indicated that the choice of the resources in B. atratus and B. bellicosus was influenced by their proboscis length. Bombus atratus has a longer proboscis and preferably visited red clover, possibly obtaining nectar easier and faster than B. bellicosus, which has a shorter proboscis. Bombus bellicosus used both resources without any clear preference.

Morphometric Analysis of Populations of Centris aenea Lepeletier (Hymenoptera: Apidae) from Northeastern Brazil

Centris aenea Lepeletier is a solitary bee that has raised interest in management to pollinate crops, such as acerola, Malpighia emarginata. This study investigated the level of morphometric variability among populations of C. aenea from Northeastern Brazil. Traditional and geometric morphometric analyses were used. Head length, leg length, wing length, and wing shape were measured in samples (5-10 females) from eight localities. We did not find statistically significant differences among the populations (P > 0.01). The partial wing warps were similar in the populations and indicated that the bees were not morphometrically different. Our results suggest that C. aenea shows low population morphometric variability and highlight the need for further investigations on population variation in this species, preferably including populations sampled at the extremes of their geographic distribution. Significant insight into the population variation of C. aenea will probably require the use of molecular markers to allow a comparative approach between morphometric variability and genetic variability.

A metallic impregnation technique adapted to study the honeybee Apis mellifera L. brain

In order to visualize the distribution pattern of the neuronal bodies and neurofibrils in the honeybee brain, we adapted a metallic impregnation technique first described for vertebrate nervous system by Ramón y Cajal. The honeybee brain constitution plays a key role in the development of learning and memory capacities. The general characteristics observed in the honeybee brain, stained by metallic impregnation, revealed its anatomical and morphological constitution in agreement with studies of other insect brains using different techniques. Metallic impregnation evidenced the optic lobe neuropils, the ocelli fiber cells, the neuron extensions of the calyces, and the axon bundles that involve the antennal glomeruli, as well as the neuron extensions in the alpha lobe. We also observed that the antennal glomeruli were mainly formed by fibers. The optical lobes were impregnated distinctly in the monopolar neuron bodies and in the fibers. In the mushroom bodies, we observed the lip, collar and calyx basal areas. Based on our results, the metallic impregnation technique is effective to visualize neuronal bodies and neurofibrils; moreover, is simpler and faster than other techniques, offering new insights for the investigation of the invertebrate nervous system.

Notes on the identity of Halictus glabrescens Cockerell and description of a new species of Halictillus Moure (Hymenoptera, Apidae s.l., Halictinae)

A lectotype is newly designated for Halictus glabriventris Friese (a homonym and replaced by H. glabrescens Cockerell) and the name transferred from Halictillus (Augochlorini) to Dialictus (Halictini), where it is a junior synonym of Dialictus spinolae (Reed). This placement resolves a long standing confusion involving the association of this name with a nest description from the beginning of the last century. In addition, a new species of Halictillus from Chile is described and figured.

Morphology of male reproductive system of two solitary bee species (Hymenoptera: Apidae)

Bees can form all levels of social organization, from solitary to advanced eusocial societies. Although 80 percent of the species exist as solitary species, most researches emphasize social species. This study focuses on the description of the male reproductive system of the solitary beesThygater analis (Lepeletier) and Melitoma segmentaria (Fabricius) and searches for traits that support behavioral and phylogenetic studies. The reproductive system of males were dissected, fixed in 2.5 percent glutaraldehyde in 0.1 M sodium cacodylate buffer pH 7.2 and post-fixed with 1 percent osmium tetroxide. The tissue was dissected and included for light microscopy. The species presented similar anatomical traits, including paired testicles, seminal vesicles, deferent ducts, accessory glands and an ejaculatory duct. Each testicle was composed of four follicles. In both species, a testicle and a seminal vesicle were surrounded by a joint capsule, forming a seminal vesicle-testicle complex. The two species presented accessory glands with very distinct morphological traits. The anatomic pattern and the histological traits of the reproductive system of the species studied were similar to those described for other bees. In addition, these traits can be used to differentiate species and allow inferences concerning their reproductive biology.

Nesting Behavior of Centris (Hemisiella) vittata Lepeletier (Hymenoptera: Apidae) in an area of the cerrado in the northeast of the State of Maranhão, Brazil

The nesting behavior of Centris (Hemisiella) vittata Lepeletier was studied in the Urbano Santos Cerrado in the northeast of Maranhão State, Brazil. To date, this species has only been studied in trap-nests. The nesting behavior of this species in a natural condition is recorded for the first time. Nesting occurred in preexisting holes in dead trunks of aroeira, Astronium myracrodruon (Anacardiaceae), at the end of the rainy season. The cells were constructed with a mixture of sand and oil. After finishing the nests, females used only oil to line the entrance wall. Two females collected sand at the same time to build their nests, and another one was seen collecting resources at Byrsonima sp. (Malpighiaceae). The pollen load of one bee was analyzed and was found to contain mainly Hymenaea courbaril (Leg-Caesalpiniaceae). Development from egg to adult took about 60 days. Protandry was observed, being males smaller than females. The nests were parasitized by Coleoptera and Diptera. However, the females only showed aggressive behavior against females of the same species or genus.

Two new species of nocturnal bees of the genus Megalopta (Hymenoptera: Halictidae) with keys to species

Megalopta Smith, 1853, is a Neotropical genus of nocturnal or crepuscular bees. Two subgenera are recognized with most of its nearly 30 species placed in the nominate subgenus. Species of Megalopta s. str. are more commonly collected than species of Noctoraptor Engel et al. 1997, all presumably parasites of Megalopta s. str. Two new species of Megalopta are described here: M. (Megalopta) tetewana, n. sp., from Mexico and M. (Noctoraptor) huaoranii, n. sp., from Ecuador. Identification keys to the Central American species of Megalopta s. str. and the species of the parasitic subgenus Noctoraptor are presented. Rev. Biol. Trop. 58 (1): 255-263. Epub 2010 March 01.

Megalopta Smith, 1853, es un género Neotropical de abejas nocturnas o crepusculares. Dos subgéneros son reconocidos con la mayoría de las 30 especies ubicadas en el subgénero nominal. Las especies de Megalopta s. str. son más comúnmente recolectadas que las especies de Noctoraptor Engel et al. 1997, todas probablemente parásitas de Megalopta s. str. Aquí se describen dos especies nuevas de Megalopta: M. (Megalopta) tetewana, n. sp., de México y M. (Noctoraptor) huaoranii, n. sp., de Ecuador. Se presentan claves de identificación para las especies de Megalopta s. str. de América Central y las especies del subgénero parásito Noctoraptor.

Uma nova espécie de Xylocopa (Monoxylocopa) Hurd & Moure e novos registros de X. abbreviata Hurd & Moure (Hymenoptera: Apidae) / A new species of Xylocopa (Monoxylocopa) Hurd & Moure and new records of X. abbreviata Hurd & Moure (Hymenoptera: Apidae)

Xylocopa (Monoxylocopa) macambirae sp. nov. is described from specimens collected mainly in areas at moderately high altitude of Northeastern brazil, inside the caatinga semi-arid domain. Additionally, a complementary diagnosis for the subgenus is presented.

Espécies novas de Anthrenoides Ducke (Hymenoptera, Apidae, Andreninae) da Argentina / New species of Anthrenoides Ducke (Hymenoptera, Apidae, Andreninae) from Argentina

São descritas e ilustradas as seguintes espécies: A calderensis sp. nov., A. cordobensis sp. nov., A. gibberosus sp. nov., A. neffi sp. nov., A. punctatus sp. nov., A. saltensis sp. nov., A. sanpedroi sp. nov., A. tucumanus sp. nov. e A. villaguayensis sp. nov. É apresentada uma chave para a sua identificação.

Anthrenoides calderensis sp. nov., A. cordobensis sp. nov., A. gibberosus sp. nov., A. neffi sp. nov., A. punctatus sp. nov., A. saltensis sp. nov., A. sanpedroi sp. nov., A. tucumanus sp. nov. and A. villaguayensis sp. nov. are described and illustrated. A key to identify the species is presented.