Search

Stingless bees, important pollinating insects in the tropics, produce honey whose unique quality features differentiate their origin. The feasibility of multivariate data analysis for quality discrimination of stingless bee honey from different genera (Melipona bicolor, quadrifasciata, marginata and Scaptotrigona bipunctata) by mineral content, physicochemical and microbiological properties were investigated. The principal component analysis explained 72.12% of the total variance of the data, and the separation into two main groups in a scatter plot was observed. Group 2 was formed by Scaptotrigona genus, that showed the highest values of pH, ash, and soluble solids. Potassium was the most abundant mineral followed by calcium and sodium for both groups quantified by inductively coupled plasma optical emission spectrometry. This honey has higher acidity and moisture than Apis mellifera honey. Microbiological analyses showed that total aerobic mesophiles ranged between 2.00 and 4.77 log CFU/g. Salmonella spp. was not detected, while the mould and yeast content was above the maximum allowed under the Apis mellifera honey legislation. The evaluated honey samples presented the lactic acid bacteria, which are considered a benefit. The multivariate statistical analysis was efficient in discriminate stingless bee honey, contributing to approaches that can be used for standardization and regulation.

Under standard greenhouse conditions, the tomato fruits of spontaneous self-pollination are expected to be of lower quality than those of bee pollination, as well as that simultaneously use different bee species which can complement pollination services. To test these hypotheses, we evaluated the complementarity of pollination services from the use of three native stingless bee species that have distinct foraging behaviors, Melipona bicolor Lepeletier 1836, Nannotrigona testaceicornis (Lepeletier 1836) and Partamona helleri (Friese 1900) during flowering of cherry tomatoes in greenhouses. Fruit quality parameters resulted from pollination experiments were measured and the acclimatization of the analyzed bee species was evaluated. Visits of M. bicolor and N. testaceicornis to the tomato flowers contributed significantly to the increase in the average weight, seed number, and thickness of the pericarp (only for N. testaceicornis ) of the fruits, compared to the spontaneous self-pollination treatment. Partamona helleri, however , did not show any pollen collection behavior in the experimental conditions. Although N. testaceicornis do not perform the buzzing behavior, fruits from its pollination were equivalent to those fruits from pollination by M. bicolor. The simultaneous use of bee species with different flower-visiting behaviors can optimize tomato pollination in greenhouses, contributing significantly to the quality of the fruits and the increase of productivity and consequently the commercial value.

Meliponine is a honey with particular characteristics; it has a high percentage of humidity, which can favor the development of microorganisms, thereby causing changes in the quality of the product. The objective of this study was to evaluate the microbiological characteristics of meliponine honey produced by different species and marketed in the State of Paraná-Brazil. The sample unit was composed of honey of Tetragonisca angustula (n = 15), Scaptotrigona bipunctata (n = 05), Melipona quadrifasciata quadrifasciata (n = 05) and Melipona bicolor schencki (n = 01). The following microbiological parameters were evaluated: counts of total and thermotolerant coliforms, fungi count and detection of Salmonella spp. Principal component analysis (PCA) was used to evaluate the possible relationships among species, locality and type of microorganism. For microorganisms of the total coliform group, 15.38% of the analyzed samples had values >3 MPN/g. The presence of thermotolerant coliforms was observed in 7.69% of the samples, all of which were T. angustula samples. For fungi counts, 100.00% of the analyzed samples had values within the established range created by the Agricultural Defense Agency of Paraná. The presence of Salmonella spp. was not observed in any of the samples evaluated. The amount of water in the honey is related to the location of the apiary and edaphoclimatic factors. Adoption of good handling practices by beekeepers is indispensable for the safety of the final product. La meliponíne produce una miel diferenciada con características particulares, presenta un alto porcentaje de humedad, lo que puede favorecer el desarrollo de microorganismos provocando cambios en la calidad del producto. El objetivo de este estudio fue evaluar las características microbiológicas de la miel de meliponíne producida por diferentes especies y comercializada en el Estado de Paraná-Brazil. La unidad de muestra estuvo compuesta por miel de Tetragonisca angustula (n = 15), Scaptotrigona bipunctata (n = 05), Melipona quadrifasciata quadrifasciata (n = 05) y Melipona bicolor schencki (n = 01). Se evaluaron parámetros microbiológicos: recuento de coliformes totales y termotolerantes, recuento de hongos y detección de Salmonella spp. Análisis de componentes principales: se utilizó ACP para evaluar las posibles relaciones entre especies, localidad y tipo de microorganismo. Para los microorganismos del grupo de coliformes totales, el 15,38% de las muestras analizadas presentaron valores >3 NMP/g. En el 7.69% de las muestras se observó la presencia de coliformes termotolerantes, siendo todas muestras de T. angustula. Para contar hongos, el 100,00% de las muestras analizadas presentaron valores dentro de lo establecido por la Agencia de Defensa Agropecuaria de Paraná. No se observó presencia de Salmonella spp en ninguna de las muestras evaluadas. Algunas muestras fueron similares según la especie productora y la cantidad de agua en la miel está relacionada con la ubicación del meliponario, debido a factores edafoclimáticos. La adopción de buenas prácticas de manipulación por parte de los productores de miel es fundamental para garantizar la seguridad alimentaria del producto final. Os meliponíneos elaboram um mel diferenciado com características particulares, apresenta elevado percentual de umidade o que pode favorecer o desenvolvimento de microrganismo ocasionando alterações na qualidade do produto. O objetivo deste estudo foi avaliar as características microbiológicas do mel de meliponíneos produzido por diferentes espécies e comercializado no Estado do Paraná-Brasil. A unidade amostral foi composta de mel de Tetragonisca angustula (n=15), Scaptotrigona bipunctata (n=05), Melipona quadrifasciata quadrifasciata (n=05) e Melipona bicolor schencki (n=01). Parâmetros microbiológicos foram avaliados: contagem de coliformes totais e termotolerantes, contagem de fungos e detecção de Salmonella spp. A análise de componentes principais - ACP foi utilizada para avaliar as possíveis relações entre espécie, localidade e tipo de microrganismo. Para microrganismos do grupo coliformes totais, 15,38% das amostras analisadas apresentaram valores >3 NMP/g. Em 7,69% das amostras foi observado a presença de coliformes termotolerantes, sendo todas amostras de T. angustula. Para contagem de fungos, 100,00% das amostras analisadas apresentaram valores dentro do estabelecido pela Agência de Defesa Agropecuária do Paraná. Não foi observado a presença de Salmonella spp em nenhuma das amostras avaliadas. Algumas amostras se assemelharam segundo a espécie produtora e a quantidade de água no mel é relacionada com a localização do meliponário, devido a fatores edafoclimáticos. Adoção de boas práticas de manipulação pelos meliponicultores se tornam indispensáveis para conferir segurança alimentar ao produto final.

Melipona bicolor schencki occurs in southern Brazil and at high elevations in southeastern Brazil. It has potential for use in meliponiculture but this stingless bee species is vulnerable to extinction and we have little knowledge about its ecology. In order to gather essential information for species conservation and management, we made a study of seasonal flight activities in its natural environment. We sampled bees entering the nests with pollen, nectar/water and resin/mud, in five colonies during each season. In parallel, we analyzed the influence of hour of the day and meteorological factors on flight activity. Flights were most intense during spring and summer, with daily mean estimates of 2,100 and 2,333 flights respectively, while in fall and winter the daily flight estimate was reduced to 612 and 1,104 flights, respectively. Nectar and water were the most frequently-collected resources, followed by pollen and building materials. This preference occurred in all seasons, but with variations in intensity. During spring, daily flight activity lasted over 14 hours; this period was reduced in the other seasons, reaching eight hours in winter. Meteorological factors were associated with 40.2% of the variation in flight and resource collection activity. Apparently, other factors that we did not measure, such as colony needs and availability of floral resources, also strongly influence the intensity of resource collection. Melipona bicolor schencki ocorre no Sul e em regiões de altitude elevada no Sudeste do Brasil. Encontra-se vulnerável a extinção no Rio Grande do Sul e possui potencial para meliponicultura, entretanto o conhecimento de sua ecologia é escasso. Desenvolveu-se o estudo sazonal das atividades de vôo de colônias em ambiente natural, com vistas a subsidiar ações conservacionistas e manejo. Amostrou-se o ingresso de pólen, néctar/água e resina/barro em cinco colônias, durante o período de atividades externas, em cada estação do ano. Analisou-se também a influência do horário e de fatores meteorológicos sobre o vôo. Os vôos foram similarmente mais intensos durante a primavera e verão, com estimativa diária de 2100 e 2333, enquanto no outono e inverno reduziram-se respectivamente para 612 e 1104. O transporte de néctar/água foi maior, seguido de cargas de pólen e de materiais de construção. Esta situação ocorreu similarmente nas quatro estações, porém com variações de intensidade. A amplitude diária de vôo foi de 14 horas na primavera, reduzindo-se nas demais estações e atingindo 8 horas no inverno. Os fatores meteorológicos exerceram influência de 40,2% no vôo das abelhas. Este resultado indica que outros fatores, não mensurados neste estudo, como as necessidades das colônias determinadas por fatores fisiológicos e a disponibilidade de recursos florais, exercem forte influência sobre a intensidade de coleta de recursos.

We studied queen-worker conflict over male production in a Melipona bicolor colony, having three physogastric queens and individually marked workers, by means of observations of the processes of cell oviposition. The gender that developed from these cells showed that queens produced mainly female offspring. The overall percentage of the males that were workers’ sons was estimated between 27 and 82%. Forty-two times workers were seen to deposit a male egg, normally following the queen’s oviposition, in the same cell and in sixteen cases, the reproductive worker ate the egg already present in the cell before ovipositing in it. Workers not only were more likely to lay their egg next to that of another worker than next to a queen’s egg, they also were more likely to replace the egg already present when it was worker-derived. Their conduct agrees with predictions from kin-selection theory because workers are better served when rearing sons at the cost of other workers’ sons than at the cost of queens’ daughters.

The stingless bee Melipona bicolor is facultatively polygynous, a unique character among the bees. Polygynous colonies were not more productive than monogynous colonies. During the process of provisioning and oviposition of cells (POP) a queen may be either alone or together with one or two other queens. If together, each queen has on average the same chance to lay the egg, indicating that there is no dominance mechanism involved. During the POP, a queen may ingest some of the larval food and a trophic egg laid by a worker. Worker egg laying is less frequent in multiple queen POPs. The most active queen has proportionally more single-queen POPs and more trophic eggs. Such nutritional advantage and the resulting output of eggs could depend on chance, but a lasting qualitative difference among queens probably exists as well. Though we could outline the mechanisms behind the outcome of this scramble competition for egg laying, the adaptive significance of this polygyny remains largely mysterious.

Made available in DSpace on 2022-04-28T20:00:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-04-01 The aim of the present study was analyze, by histological and morphometrical studies, mandibular glands of Melipona bicolor queens collected from monogynic and polygynic colonies and compare their level of development. The results showed that the glands of physogastric queens from monogynic colony present a higher level of activity in relation to the queens of polygynic colonies; this is explained by the fact that just a unique queen controls the monogynic colony. In the polygynic colonies, the queens may divide such control to each other. Departamento de Biologia Instituto de Biociências Universidade Estadual Paulista (UNESP), Rio Claro, SP Departamento de Biologia Instituto de Biociências Universidade Estadual Paulista (UNESP), Avenida 24A, n 1515, CEP 13506-900, Bela Vista Departamento de Biologia Instituto de Biociências Universidade Estadual Paulista (UNESP), Rio Claro, SP Departamento de Biologia Instituto de Biociências Universidade Estadual Paulista (UNESP), Avenida 24A, n 1515, CEP 13506-900, Bela Vista

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:21:08Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:34:13Z : No. of bitstreams: 1 2-s2.0-9644291473.pdf: 125314 bytes, checksum: f6cf752da95c5b4c77e7d5ca84e284ae (MD5) Made available in DSpace on 2014-05-27T11:21:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-09-01 We describe differences in the chemical composition of the Dufour gland secretion of virgin and physogastric queens of Melipona bicolor through gas chromatography and mass spectrometry. The Dufour gland secretion of virgin queens consists only of hydrocarbons, while that of physogastric queens contains, besides these, a variety of other compounds, such as isobutyrate and acetate esters. Such differences may indicate the queen fecundity condition and the oxygenated compounds of the physogastrics secretion may help to increase their attractiveness. Departamento de Biologia Institute de Biociências Universidade Estadual Paulista, Avenida 24A, 1515, 13506-900 Rio Claro - SP Department of Chemistry Keele University, Staffordshire, ST5 5BG Departamento de Biologia Institute de Biociências Universidade Estadual Paulista, Avenida 24A, 1515, 13506-900 Rio Claro - SP

The occurrence, morphology and ultrastructure of the Dufour gland in Melipona bicolor Lepeletier, 1836 are presented. The Dufour gland is not present in workers. In virgin queens the gland cells show characteristics of low activity, which are described in the text. In physogastric queens the gland epithelium is higher and the cells more active than in virgin queens, showing numerous basal plasmic membrane invaginations impregnated by an electrondense material, increased apical invaginations and accumulation of substances that will be released to the gland lumen in the subcuticular space. Therefore, the data show that the Dufour gland is more developed in physogastric than in virgin queens, indicating a possible involvement of the Dufour gland in the reproduction of this species.A ocorrência, morfologia e ultra-estrutura da glândula de Dufour em Melipona bicolor Lepeletier, 1836 são apresentados. A glândula de Dufour não está presente nas operárias. Nas rainhas virgens, as células glandulares mostram características de baixa atividade, as quais são descritas no texto. Nas rainhas fisogástricas, o epitélio glandular é mais alto e as células mais ativas do que nas rainhas virgens, mostrando numerosas invaginações da membrana plasmática basal impregnadas por material eletrondenso, além do aumento da freqüência de invaginações apicais e acúmulo de substâncias no espaço subcuticular, as quais serão posteriormente liberadas ao lúmen da glândula. Portanto, os dados mostram que a glândula de Dufour é mais desenvolvida nas rainhas fisogástricas do que nas virgens, indicando um possível envolvimento da glândula de Dufour na reprodução desta espécie.

Dufour glands of Apis mellifera and Melipona bicolor were studied under light and transmission electron microscopy, using the cytochemical techniques of mercury bromophenol blue for protein detection, imidazole-buffered osmium tetroxide selective staining of unsaturated lipids, lanthanum nitrate for intercellular junction identification and zinc-iodide-osmium tetroxide for cytoplasmic endomembrane visualization. The results in both species corroborated the lipid nature of the gland secretion and showed in A. mellifera the poverty of the synthetic machinery in the worker gland cells in comparison with the queen, as expected by previous biochemical analyses. The pathway of the exogenous compounds of the secretion is intracellular, since substances can penetrate the cell folds and intercellular junctions, but their access to the gland lumen is barred by the apical intercellular junctions.

We evaluated the ability of two Brazilian stingless bee species, Melipona mandacaia and M. bicolor ,t o recruit nestmates to a specific three-dimensional location. We used experimental feeder arrays and provide the first detailed evidence demonstrating that recruitment communication in Melipona can lead to large, rapid and highly significant increases in the number of nestmates visiting a specific location. Melipona bicolor and M. mandacaia foragers both recruited nestmates to the correct distance and direction, but differed in their ability to recruit nestmates to the correct height. These differences may relate to their respective habitats. Melipona mandacaia inhabits semi-arid areas of Caatinga where most food sources occur close to the ground, and its foragers evidently cannot recruit nestmates to the correct height. Melipona bicolor, an Atlantic rainforest species, evidently does not communicate height when the food source is at ground level, but can communicate height when the food source is at the forest canopy level (12 m high), where major food sources occur. Species-specific variation in three-dimensional location communication is intriguing because it suggests that Melipona may be a good model for studying the evolution of recruitment communication systems in highly social bees.  2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.

It is unclear whether stingless bees in the genus Melipona (Hymenoptera, Apidae, Meliponini) can reli- ably encode the distance to a food source through recruitment sounds produced inside the nest, in part because the sound features correlated with distance also vary with food quality. We therefore trained marked foragers of two species, Melipona mandacaia and M. bicolor, to feeders at different distances and to different sucrose concentrations at the same distance. In both species, foragers successfully recruited to a rich 2.5-m food source and produced pulsed recruitment sounds in which pulse duration was significantly and positively correlated with distance to the rich food source. When returning from poorer food sources (0.6-1.5 m), foragers of both species decreased sound production, producing shorter sound pulses and longer sound interpulses than they did for 2.5 m food located at the same distance. Thus the temporal structure of M. mandacaia and M. bicolor recruitment sounds varies with distance and food quality. However, nestmates were not recruited by performances for poorer food sources (0.6-1.5 m), whose sucrose concentration was sufficiently low to affect recruitment sounds. Surprisingly, the interphase (the time between behavioral phases that communicate location) also in- creases with decreasing food quality in the closely related honeybees (Apis), suggesting a potential homology in the effect of food quality on the recruitment systems of Apis and Melipona. We explore the evolutionary implications of these similarities.

The present paper describes the ultrastructural features of seminal vesicle, post-vesicular vas deferens and ejaculatory duct of Melipona bicolor bicolor from newly emerged and mature males. Although the results do not show very consistent morphological signs of secretory activity by the epithelium of these organs, lipidic droplets and lamellar granules present in mature males' seminal vesicles and the vacuoles present in post-vesicular vas deferens are probably secretion. Besides, the spermatozoa in the lumen are immersed in a material of characteristic structure, which must be produced in superior regions of the reproductive system of immature males, not studied here. The presence of sperm cells, apparently in cytoplasm vesicles of seminal vesicle and post-vesicular vas deferens, suggests spermiophagy by their epithelium.

Young virgin queens of the stingless bee Melipona bicolor have been shown to produce wax like workers. The small, white to transparent flakes of wax of the queens protrude from the intersegmental space and cover the anterior part of the tergite cuticle, in a way similar to that in workers. This points to the presence of wax glands in the queens. However, workers produce wax from glands located at the fourth to seventh tergites whereas queens secrete wax from the epidermal gland at the third tergite only. Analysis of the queen-produced wax showed that it contains the same substances as the worker-produced wax with minor differences in composition. The wax consists chiefly of the long-chain esters triacontanyl acetate and octacosanyl acetate, smaller amounts of linear C21 to C31 alkanes and alkenes, and still smaller quantities of linear aldehydes and isobutyrate esters. Analysis of wax from wax deposits and wax constructs showed the same composition. Wax from M. bicolor is similar to that of other stingless bees in containing the range of linear long-chain alkenes and alkanes and different from that of Apis bees which contains a more complex mixture, less hydrocarbons and more long chain esters.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:23Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:44:49Z : No. of bitstreams: 1 2-s2.0-0036337154.pdf: 2204295 bytes, checksum: 169ece704d6f06a797f183123aef89bd (MD5) Made available in DSpace on 2014-05-27T11:20:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-01-01 The present paper reports morphological features of the testes reabsorption in adult male of Melipona bicolor bicolor. The ultrastructural features of the degenerating sperm cells and cyst cells are described. It is suggested that the material of the reabsorbed testes may serve as nutritional source for the adult male. Departamento de Biologia Inst. de Biociencias de Rio Claro UNESP, Av. 24 A, no 1515, CEP 13506-900, Rio Claro-SP Departamento de Biologia Inst. de Biociencias de Rio Claro UNESP, Av. 24 A, no 1515, CEP 13506-900, Rio Claro-SP

On a worldwide scale, Brazil is the country hosting the greatest number of stingless bee species. The species natural distribution favours the Amazonian basin, even though the Meliponinies settlement area (family to which these insects belong) covers the entire national territory. In southern Brazil, Meliponinies domestication for a long time concerned exclusively the Tetragonisca angustula, a very common species in Latin America, and some melipona: Melipona bicolor, M. marginata, M. quadrifasciata. The harsh pressure on nests linked with the destruction of natural habitats provoked a tremendous decline in wild bee populations. In the state of Santa Catarina, a majority of native bees is still threatened of disappearing despite a very restrictive law adopted in August 2004 by the Brazilian parliament. In urban areas like Chapeco city (175,000 inhabitants), the breeding of Meliponinies has been developing intensively over the past fifteen years. Nowadays, between 1,800 and 2,000 bee colonies and 21 species of Meliponini are managed in the average sized inland town by 50-80 new bee-keepers. Generally they want to sell (honey trade) their production or raise bees as a hobby (leisure). This urban meliponiculture may thus represent a way of conserving these bee species.

Resumo. No presente estudo realizou-se um levantamento de ninhos de abelhas Meliponini na Estação Ecológica de Água Limpa (EEAL), no município de Cataguases, Minas Gerais. Foram encontrados 21 ninhos pertencentes a nove espécies: Friesella schrottkyi (Friese), Melipona bicolor Lepeletier, Plebeia sp. 1, Plebeia sp. 2, Tetragona clavipes (Fabricius), Tetragona quadrangula (Fabricius), Tetragonisca angustula (Latreille), Trigona hyalinata (Lepeletier), Trigona spinipes (Fabricius). Vinte dos 21 ninhos foram encontrados em substrato arbóreo. A fauna de Meliponini observada na EEAL é representada por um baixo número de espécies. Embora a vegetação local tenha potencial para oferecer substratos para nidificação e recursos florais, a baixa riqueza de espécies pode estar relacionada com o fato da EEAL ser um remanescente florestal isolado. Stingless Bees of the Estação Ecológica de Água Limpa, Cataguases-MG, Brazil Abstract. This study carried out a survey of nests of stingless bees present in the Estação Ecológica de Água Limpa (EEAL) in the municipality of Cataguases, Minas Gerais. We found twenty-one nests belonging to nine species: Friesella schrottkyi (Friese), Melipona bicolor Lepeletier, Plebeia sp. 1, Plebeia sp. 2, Tetragona clavipes (Fabricius), Tetragona quadrangula (Fabricius), Tetragonisca angustula (Latreille), Trigona hyalinata (Lepeletier), Trigona spinipes (Fabricius). Twenty of the 21 nests were found in arboreal substrate. The fauna of stingless bees observed in EEAL is represented by a low number of species. Although the local vegetation has the potential to provide substrates for nesting and floral resources, the low species richness may be related to the fact that the EEAL is an isolated forest remnant.

As in many other stingless bees, Melipona bicolor bicolor Lepeletier (Apidae: Meliponinae) workers lay two morphologically distinct types of eggs: slender ones that have a typical patterned chorion, and larger ones that lack this pattern. In this paper we report on the relation between egg morphology and the behaviour of the workers that lay such eggs. In most cases, the laying of each of these egg types is accompanied by a unique sequence of behaviours. After a worker has laid the unpatterned type of egg, she generally leaves the cell, giving the queen the possibility of eating this egg. In the case of the patterned egg type, the worker usually closes the cell immediately after her egg laying. When worker egg laying occurs right after a series of regurgitations, it stops the queen from ovipositing. When, instead, a worker lays an egg after queen oviposition, the cell contains two eggs. This study also revealed cases in which workers laid slender, patterned eggs without closing the cell, and other cases where workers laid large, spherical, unpatterned eggs and instantly closed the cell. Experiments in which worker eggs, destined to be eaten by the queen, were protected by covering the cell artificially with a piece of wax showed that some of these eggs developed into larvae, although they were occasionally relatively small. The occurrence of a range of combinations of egg-laying behaviours and egg morphologies in M. b. bicolor workers is discussed from the perspective of worker egg laying in other stingless bees.

Flight activity of Melipona bicolor bicolor, coming from Cunha (23º05'S, 44º55'W), Atlantic Forest, was studied in ten colonies, and in two periods: from July to September 1993 and from August to September 1995. The colonies were grouped in weak, medium and strong, according to the diameter of the combs, which can provide a good idea of the number of cells built. 855 observations were accomplished for 5 minutes, every half-hour, from 8 to 18 hours. The total number of bees that entered and left the hive and the number of bees that arrived with mud, pollen and resin, besides the number that went out with debris in that period were counted. It was also registered the temperature and the relative humidity of the air. The total external activity, as well as pollen collection, was maximum in the first hours of the morning, mainly in strong colonies. Weak colonies moved their maximum activity approximately to 12 hours. Pollen collection declined gradually, while mud and resin collection rose; removal of debris was greater in the beginning of the morning and in the end of the afternoon. Flight activity increased as relative humidity of the air rose, being optimum for strong colonies in the range between 80%-89%, and for the weakest colonies between 70%-79%. The minimum temperature observed for exit of the bees was 11ºC, with optimum temperatures ranging between 17ºC and 22ºC. The results showed that the general state of the colony influences the different strategies of food collection and that these bees should be adapted to environments of high relative humidity as the Atlantic forest.

Bees are manufacturers of relevant economical products and have a pollinator role fundamental to ecosystems. Traditionally, studies focused on the genusMeliponahave been mostly based on behavioral, and social organization and ecological aspects. Only recently the evolutionary history of this genus has been assessed using molecular markers, including mitochondrial genes. Even though these studies have shed light on the evolutionary history of theMeliponagenus, a more accurate picture may emerge when full nuclear and mitochondrial genomes ofMeliponaspecies become available. Here we present the assembly, annotation, and characterization of a draft mitochondrial genome of the Brazilian stingless beeMelipona scutellarisusingMelipona bicoloras a reference organism. Using Illumina MiSeq data, we achieved the annotation of all protein coding genes, as well as the genes for the two ribosomal subunits (16S and 12S) and transfer RNA genes as well. Using the COI sequence as a DNA barcode, we found thatM. cramptoniis the closest species toM. scutellaris.

Dans une zone protegee de la foret ombrophile cotiere pres de Sao Paulo, on a preleve sur une annee des echantillons de pollen et de miel dans deux colonies de Melipona bicolor et deux de M quadrifasciata (abeilles sans aiguillon) et dans deux colonies d'abeilles africanisees, Apis mellifera, et on a fait des analyses polliniques de ces echantillons. Des pelotes de pollen ont ete recoltees au moins deux fois par mois i) sur des ouvrieres capturees devant le trou de vol (Melipona), ii) dans des trappes a pollen (Apis). En outre des echantillons de pollen et de miel ont ete preleves chaque mois dans les pots de reserve nouvellement remplis des colonies de Melipona et dans les nouveaux rayons des colonies d'Apis (dans deux cadrons suspendus le mois precedent). Les echantillons ont ete traites et les preparations polliniques realisees selon Vorwohl (1977) et Louveaux et al (1970). Pour les echantillons de pollen, on a estime les pourcentages relatifs en poids et en volume des types polliniques (Vorwohl, 1977; Biesmeijer et al, 1992). Le recouvrement des niches alimentaires (NO) a ete calcule d'apres Colwell et Futuyama (1971). Pour mesurer l'impact potentiel de l'abeille africanisee on a defini un indice de competition (PC Am ), qui est le produit du recouvrement des niches et de la recolte globale des abeilles africanisees. Dans la foret ombrophile de Boraceia les colonies de melipones ont recolte du pollen et du nectar tout au long de l'annee. La recolte de pollen (nombre de pots a pollen nouvellement remplis) a ete maximale en novembre (figs 1 et 2), tandis que la recolte de miel (nouveaux pots a miel) a presente deux maximums, l'un en juillet et l'autre en decembre (fig 3). Aout et decembre ont ete les mois ou les colonies d'abeilles africanisees ont engrange le plus de pollen et de miel, respectivement (fig 4). Dans les echantillons de pollen et de miel des colonies de Melipona, les Myrtacees et les Melastomatacees ont domine presque toute l'annee (tableau II et III; fig 5) ; cela confirme les etudes d'autres auteurs realisees dans des habitats principalement influences par l'homme. L'abeille africanisee a utilise un large spectre de plantes nourricieres (tableau I), caracterise par un renouvellement presque mensuel des principales ressources (tableaux II et III). Les differences entre les echantillons provenant des ouvrieres et ceux issus des pots a pollen s'expliquent par les faits suivants : i) par butinage intense, toutes les ouvrieres rentrant a la colonie avec des pelotes ne peuvent pas etre capturees devant le trou de vol, c'est pourquoi, dans ces echantillons, les plantes qui fleurissent en masse et peu longtemps sont sous-representees ; ii) selon Sommeijer et De Bruijn (1994), les abeilles Melipona ont une forte tendance a fermer les pots a pollen; apres une forte rentree de pollen il est possible que le pollen rapporte soit traite sans passer par les pots a pollen, si bien que les pollens qui ne sont disponibles que peu de temps et en petites quantites sont a peine presents dans les pots a pollen. La quantite absolue du pollen preleve sur les butineuses ne depend pas seulement de l'offre pollinique mais aussi des conditions meteorologiques les jours ou les prelevements sont faits. Le nombre de pots a pollen nouvellement remplis nous semble plus approprie pour evaluer la quantite de pollen rapporte a la colonie. Le recouvrement des niches est plus important pour les deux especes de melipones entre elles (moyenne annuelle 0,66 et 0,82 pour les echantillons de pollen provenant respectivement des butineuses et des pots a pollen et 0,68 pour les echantillons de miel) qu'entre les melipones et l'abeille mellifere (0,27 et 0,44 pour M bicolor, 0,23 et 0,5 pour M quadrifasciata

International audience; Melipona bicolor schencki is currently considered a threatened stingless bee in southern Brazil, and studies about its ecology may provide new insights to enable its conservation. This study evaluated the seasonal variability in the sex/caste proportion, numbers of combs and brood cells, and spatial distribution of the individuals present in emerging combs in five polygynous colonies of M. bicolor schencki for 1 year. Throughout the year, the colonies showed similar variations. Individual combs exhibited a higher number of brood cells in spring and summer, although there was no variation in the number of combs over the four seasons. Workers (79.7 %), queens (15.6 %), and drones (4.7 %) were produced in all months sampled. Analysis of spatial distribution indicated no clear predominance of a specific sex or caste in a specific comb area, contrary to other species of Melipona.

International audience; In many hymenopteran insect societies, selfish workers are policed, as selfishness can negatively affect the average inclusive fitness of one or both castes by reducing either the degree of average relatedness to the colony's male offspring or colony efficiency. In stingless bees, the rapid capping of brood cells could aid in controlling selfishness; to this end, we studied cell-sealing efficacy in Melipona bicolor. Execution of cell sealing was found to be both rapid and almost continuous. Comparing the performance of reproductive and non-reproductive workers, the former sealed the cells more efficiently when they contained their own eggs, but less so when the queens' eggs were involved. We argue that the occurrence of disruptions in cell sealing through self-serving reproductive workers is capable of undermining sealing efficacy as a policing instrument, thus making reproductive workers potential rogue individuals.

Stingless bee colonies typically consist of one single-mated mother queen and her worker offspring. The stinglessbee Melipona bicolor(Hymenoptera: Apidae) shows facultative polygyny, which makes this species particularly suit-ablefortestingtheoreticalexpectationsconcerningsocialbehavior.Inthisstudy,weinvestigatedthesocialstructureandgeneticrelatednessamongworkersfromeightnaturalandsixmanipulatedcoloniesofM.bicoloroveraperiodofone year. The populations of M. bicolorcontained monogynous and polygynous colonies. The estimated genetic re-latedness among workers from monogynous and polygynous colonies was 0.75 0.12 and 0.53 0.16 (mean SEM), respectively. Although the parental genotypes had significant effects on genetic relatedness in monogynousandpolygynouscolonies,polygynymarkedlydecreasedtherelatednessamongnestmateworkers.Ourfindingsalsodemonstrate that polygyny in M. bicolormay arise from the adoption of related or unrelated queens. Key words: Melipona , microsatellites, polygyny, queen number, social structure.Received: August 6, 2010; Accepted: December 21, 2010.

At present a complete mtDNA sequence has been reported for only two hymenopterans, the Old World honey bee, Apis mellifera and the sawfly Perga condei. Among the bee group, the tribe Meliponini (stingless bees) has some distinction due to its Pantropical distribution, great number of species and large importance as main pollinators in several ecosystems, including the Brazilian rain forest. However few molecular studies have been conducted on this group of bees and few sequence data from mitochondrial genomes have been described. In this project, we PCR amplified and sequenced 78% of the mitochondrial genome of the stingless bee Melipona bicolor (Apidae, Meliponini). The sequenced region contains all of the 13 mitochondrial protein-coding genes, 18 of 22 tRNA genes, and both rRNA genes (one of them was partially sequenced). We also report the genome organization (gene content and order), gene translation, genetic code, and other molecular features, such as base frequencies, codon usage, gene initiation and termination. We compare these characteristics of M. bicolor to those of the mitochondrial genome of A. mellifera and other insects. A highly biased A+T content is a typical characteristic of the A. mellifera mitochondrial genome and it was even more extreme in that of M. bicolor. Length and compositional differences between M. bicolor and A. mellifera genes were detected and the gene order was compared. Eleven tRNA gene translocations were observed between these two species. This latter finding was surprising, considering the taxonomic proximity of these two bee tribes. The tRNA Lys gene translocation was investigated within Meliponini and showed high conservation across the Pantropical range of the tribe.

In the present study we compare genetic characteristics (allele diversity and observed heterozygosity) of microsatellite loci, from three stingless bee species (Plebeia remota Holmberg, Partamona mulata Moure In Camargo and Partamona helleri Friese), amplified by using heterospecific primers originally designed for Melipona bicolor Lepeletier and Scaptotrigona postica Latreille. We analyzed 360 individuals of P. remota from 72 nests, 58 individuals of P. mulata from 58 nests, and 47 individuals of P. helleri from 47 nests. The three species studied showed low level of polymorphism for the loci amplified with primers derived from M. bicolor. However, for the loci amplified with primers derived from S. postica, only P. remota presented low level of polymorphism.

The focus of this paper is the process for brood production known as the Provisioning and Oviposition Process (POP), and particularly the individual behavior observed in the facultatively polygy- nous stingless bee Melipona bicolor. Following individually marked bees revealed that ovarian development is correlated with individual behavior differences. While most of the eggs laid by workers are consumed by the queen (trophic eggs), workers contribute significantly in male production with reproductive eggs, illustrating the reproductive conflict at the individual level. From an evolutionary outlook, "benefactor" behaviors may evolve if workers conserve the "hope" of reproduction. This indicates that an important function of trophic eggs is to keep the ovaries active. It is also possible that ovary development represents an internal factor promoting division of labor: reproductive workers are specialized or elite bees with low response thresholds and high activity levels that restrain the participation of other workers. stingless bees / division of labor / POP / Melipona bicolor / reproductive competition / Apidae

Mitochondrial gene rearrangement events, especially involving tRNA genes, have been described more frequently as more complete mitochondrial genome sequences are becoming available. In the present work, we analyzed mitochondrial tRNA gene rearrangements between two bee species belonging to the tribes Apini and Meliponini within the "corbiculate Apidae". Eleven tRNA genes are in different genome positions or strands. The molecular events responsible for each translocation are explained. Considering the high number of rearrangements observed, the data presented here contradict the general rule of high gene order conservation among closely related organisms, and also represent a powerful molecular tool to help solve questions about phylogeny and evolution in bees.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:21:08Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:29:04Z : No. of bitstreams: 1 2-s2.0-1542655544.pdf: 110911 bytes, checksum: b9896dadc3a674cf57d6b1867bf7ab0e (MD5) Made available in DSpace on 2014-05-27T11:21:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-09-01 The mandibular gland secretions of newly emerged, nurse and forager workers, virgin and physogastric queens and males of Melipona bicolor were analyzed by gas chromatography-mass spectrometry. The secretion is composed of a blend of hydrocarbons, alcohols, esters, and acids. The secretion is caste-sex specific and also differs with the tasks performed by the workers and the physiological reproductive condition of the queens. Departamento de Biologia Instituto de Biociências Universidade Estadual Paulista, Av. 24A, 1515, 13506-900 Rio Claro - SP School of Chemistry and Physics Lennard-Jones Laboratories Keele University, Staffordshire, ST5 5BG Departamento de Biologia Instituto de Biociências Universidade Estadual Paulista, Av. 24A, 1515, 13506-900 Rio Claro - SP

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:45:47Z No. of bitstreams: 1 S0085-56262004000100002.pdf: 1578103 bytes, checksum: b66b1a2c2083c798fc9ec8297bbd5d05 (MD5) Made available in DSpace on 2013-08-22T18:45:47Z (GMT). No. of bitstreams: 1 S0085-56262004000100002.pdf: 1578103 bytes, checksum: b66b1a2c2083c798fc9ec8297bbd5d05 (MD5) Previous issue date: 2004-03-01 Made available in DSpace on 2013-09-30T19:34:53Z (GMT). No. of bitstreams: 2 S0085-56262004000100002.pdf: 1578103 bytes, checksum: b66b1a2c2083c798fc9ec8297bbd5d05 (MD5) S0085-56262004000100002.pdf.txt: 32791 bytes, checksum: 29307fcc125afa040187d22c0ce516a1 (MD5) Previous issue date: 2004-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:54:56Z No. of bitstreams: 2 S0085-56262004000100002.pdf: 1578103 bytes, checksum: b66b1a2c2083c798fc9ec8297bbd5d05 (MD5) S0085-56262004000100002.pdf.txt: 32791 bytes, checksum: 29307fcc125afa040187d22c0ce516a1 (MD5) Made available in DSpace on 2014-05-20T13:54:56Z (GMT). No. of bitstreams: 2 S0085-56262004000100002.pdf: 1578103 bytes, checksum: b66b1a2c2083c798fc9ec8297bbd5d05 (MD5) S0085-56262004000100002.pdf.txt: 32791 bytes, checksum: 29307fcc125afa040187d22c0ce516a1 (MD5) Previous issue date: 2004-03-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A ocorrência, morfologia e ultra-estrutura da glândula de Dufour em Melipona bicolor Lepeletier, 1836 são apresentados. A glândula de Dufour não está presente nas operárias. Nas rainhas virgens, as células glandulares mostram características de baixa atividade, as quais são descritas no texto. Nas rainhas fisogástricas, o epitélio glandular é mais alto e as células mais ativas do que nas rainhas virgens, mostrando numerosas invaginações da membrana plasmática basal impregnadas por material eletrondenso, além do aumento da freqüência de invaginações apicais e acúmulo de substâncias no espaço subcuticular, as quais serão posteriormente liberadas ao lúmen da glândula. Portanto, os dados mostram que a glândula de Dufour é mais desenvolvida nas rainhas fisogástricas do que nas virgens, indicando um possível envolvimento da glândula de Dufour na reprodução desta espécie. The occurrence, morphology and ultrastructure of the Dufour gland in Melipona bicolor Lepeletier, 1836 are presented. The Dufour gland is not present in workers. In virgin queens the gland cells show characteristics of low activity, which are described in the text. In physogastric queens the gland epithelium is higher and the cells more active than in virgin queens, showing numerous basal plasmic membrane invaginations impregnated by an electrondense material, increased apical invaginations and accumulation of substances that will be released to the gland lumen in the subcuticular space. Therefore, the data show that the Dufour gland is more developed in physogastric than in virgin queens, indicating a possible involvement of the Dufour gland in the reproduction of this species. Universidade Estadual Paulista Instituto de Biociências Departamento de Biologia Universidade Estadual Paulista Instituto de Biociências Departamento de Biologia

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:59Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:44:14Z : No. of bitstreams: 1 2-s2.0-2342445805.pdf: 560476 bytes, checksum: a851e60d4f288792b3d85072520652a7 (MD5) Made available in DSpace on 2014-05-27T11:20:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-12-01 In social insects, cuticular hydrocarbons are involved in species, kin, caste and nestmate recognition. Gas chromatography and mass spectrometry were used to compare the cuticular hydrocarbon composition of workers, males and queens of Melipona bicolor. The cuticular hydrocarbon composition of this species was found to consist mainly of C23, C25:1, C25, C27:1, C27, C29:1 and C29, which are already present in imagoes that have not yet abandoned the brood cell. This composition varied quantitatively and qualitatively between and within the castes and sexes. The newly emerged workers and young queens (virgins) had similar cuticular hydrocarbon profiles, which were different from those of the males. When the females start executing their tasks in the colony, the cuticular hydrocarbon profile differences appear. The workers have less variety, while the queens conserve or increase the number of cuticular hydrocarbon compounds. The queens have more abdominal tegumentary glands than the workers, which apparently are the source of the new cuticular compounds. Departamento de Biologia Instituto de Biociências Univ. Estadual Paulista (UNESP), Rio Claro, SP School of Chemistry and Physics Keele University, Staffordshire Departamento de Biologia Instituto de Biociências Univ. Estadual Paulista (UNESP), Rio Claro, SP

The mandibular gland in Melipona bicolor workers and queens was studied by scanning and transmission electron microscopy. There is no difference in the gland anatomy between the castes, but the transmission electron microscopy showed variation of the cellular ultrastructure according to the secretory phase of the gland in both castes. Smooth endoplasmic reticulum was abundant in the secretory cells of physogastric queens, indicating that these cells produce lipid secretion that is stored in granules with multi-lamellar bodies. Mitochondrial variations during the cell secretory cycle indicates their participation in the lipid synthesis. After secretion, release in the reservoir lumen through the collecting canals, the secretory cells contain many myelinic bodies, indicative of cellular regression.

The presence of spermatozoa in vesicles in the cytoplasm of the epithelial cells that constitute the spermathecal wall of Melipona bicolor queen (Meliponini) is discussed in relation to the organ structure. The epithelial wall is lined by an apparently continuous cuticle in the luminal surface that should be a non-transposable barrier to the luminal spermatozoa. However, some spermatozoa were seen crossing the cuticle through interruptions that was first interpreted as sectioning defects. Nevertheless, the sperm cells in well-structured cytoplasmic vesicles, bound by membranes and sometimes associated to multivesicular bodies, as well as cytoplasmic structures representative of intracellular digestion and the occurrence of the phenomenon in two of the three spermathecae studied, suggest a real spermiophagic hole in the spermathecal epithelial cells.

We analyzed patterns of heterochromatic bands in the Neotropical stingless bee genus Melipona (Hymenoptera, Meliponini). Group I species (Melipona bicolor bicolor, Melipona quadrifasciata, Melipona asilvae, Melipona marginata, Melipona subnitida) were characterized by low heterochromatic content. Group II species (Melipona capixaba, Melipona compressipes, Melipona crinita, Melipona seminigra fuscopilosa e Melipona scutellaris) had high heterochromatic content. All species had 2n = 18 and n = 9. In species of Group I heterochromatin was pericentromeric and located on the short arm of acrocentric chromosomes, while in Group II species heterochromatin was distributed along most of the chromosome length. The most effective sequential staining was quinacrine mustard (QM)/distamycin (DA)/chromomycin A3(CMA3)/4-6-diamidino-2-phenylindole (DAPI). Heterochromatic and euchromatic bands varied extensively within Group I. In Group II species euchromatin was restricted to the chromosome tips and it was uniformly GC+. Patterns of restriction enzymes (EcoRI, DraI, HindIII) showed that heterochromatin was heterogeneous. In all species the first pair of homologues was of unequal size and showed heteromorphism of a GC+ pericentromeric heterochromatin. In M. asilvae (Group I) this pair bore NOR and in M. compressipes (Group II) it hybridized with a rDNA FISH probe. As for Group I species the second pair was AT+ in M. subnitida and neutral for AT and GC in the remaining species of this group. Outgroup comparison indicates that high levels of heterochromatin represent a derived condition within Melipona. The pattern of karyotypic evolution sets Melipona in an isolated position within the Meliponini.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:43:52Z No. of bitstreams: 1 S0073-47212001000200025.pdf: 408215 bytes, checksum: 653ef987ea24b6ba95a65beca64ec0fc (MD5) Made available in DSpace on 2013-08-22T18:43:52Z (GMT). No. of bitstreams: 1 S0073-47212001000200025.pdf: 408215 bytes, checksum: 653ef987ea24b6ba95a65beca64ec0fc (MD5) Previous issue date: 2001-11-27 Made available in DSpace on 2013-09-30T19:31:49Z (GMT). No. of bitstreams: 2 S0073-47212001000200025.pdf: 408215 bytes, checksum: 653ef987ea24b6ba95a65beca64ec0fc (MD5) S0073-47212001000200025.pdf.txt: 15928 bytes, checksum: 742c7050ebb5b738c9fd79a97fc441bc (MD5) Previous issue date: 2001-11-27 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:08:41Z No. of bitstreams: 2 S0073-47212001000200025.pdf: 408215 bytes, checksum: 653ef987ea24b6ba95a65beca64ec0fc (MD5) S0073-47212001000200025.pdf.txt: 15928 bytes, checksum: 742c7050ebb5b738c9fd79a97fc441bc (MD5) Made available in DSpace on 2014-05-20T15:08:41Z (GMT). No. of bitstreams: 2 S0073-47212001000200025.pdf: 408215 bytes, checksum: 653ef987ea24b6ba95a65beca64ec0fc (MD5) S0073-47212001000200025.pdf.txt: 15928 bytes, checksum: 742c7050ebb5b738c9fd79a97fc441bc (MD5) Previous issue date: 2001-11-27 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The morphology of the cyst cells in Apis mellifera Linné, 1758, Scaptotrigona postica Latreille, 1804, and Melipona bicolor bicolor Lepeletier, 1836 testis, as well as the average number of spermatic cells are reported. The data indicates a supporting and nourrishing role of the cyst cells to the developing cystocytes. The counts of immature spermatozoa in the cysts show an average of 202.8 ± 21.2 spermatozoa for A. mellifera, 117.4 ± 8.68 for S. postica and 88.8 ± 15.57 for M. bicolor, which predict the occurrence of 8 mitotic cycles in the cystocytes of A. mellifera and 7 in the meliponines, considering that only one spermatozoom originates of each final spermatogonium. Universidade Estadual Paulista Instituto de Biociências Departamento de Biologia Universidade Estadual Paulista Instituto de Biociências Departamento de Biologia

La theorie de la selection de la parentele predit qu'un individu peut parvenir a l'adequation adaptative (fitness) au moyen de la reproduction indirecte en aidant l'elevage des descendants d'un parent et l'on s'attend a ce que cette aide soit dirigee de preference vers les individus qui partagent un fort degre de parente avec l'acteur. M. bicolor est la seule espece fortement eusociale connue qui presente une polygynie facultative de longue duree. Nous avons teste la tendance eventuelle des ouvrieres a faire la distinction entre des reines physogastriques qui leur sont plus ou moins apparentees. Une colonie possedant deux reines physogastriques, qui s'etaient accouplees quatre mois plus tot et etaient probablement sœurs, a ete suivie pendant cinq jours et cinq nuits de suite du point de vue des processus d'approvisionnement et de ponte (POPs). Nous avons enregistre les types de comportement suivants d'ouvrieres marquees individuellement: aprovisionnement de la cellule avant la ponte, ponte avant et apres la ponte de la reine, obturation de la cellule apres la ponte de la reine. Afin d'evaluer l'eventuelle preference de ces ouvrieres marquees pour l'une ou l'autre reine, nous avons enregistre le nombre total de comportement effectues par chaque ouvriere vis-a-vis de chaque reine. La note 1 a ete attribuee a la reine lorsque le comportement n'etait effectue que vis-a-vis d'une reine, et la note un demi a chaque reine, lorsque les deux reines etaient presentes au cours du POP. Seules les ouvrieres que nous avons vu participer a quatre POPs au moins ont ete retenues pour l'analyse (figure 1). La possibilite que les ouvrieres aient pu etre stimulees par la presence d'une reine et n'aient pas ete inhibees par la presence de l'autre a ete prise en consideration. Aussi dans une autre analyse, seuls les POPs au cours desquels une seule reine etait presente, ont ete retenus et nous avons a nouveau teste l'eventuelle preference des ouvrieres (figure 2). Dans les deux cas, les ouvrieres ayant reparti leurs activites au hasard sur les cellules frequentees par les reines, nous en concluons qu'elles n'ont pas de preference pour l'une ou l'autre des reines. Par ailleurs, nous avons retire de la colonie utilisee pour l'experience 1 l'une des reines et l'avons remplace par deux reines physogastriques non apparentees, prelevees dans d'autres colonies. Nous avons repete le suivi des comportements et refait la meme analyse de donnees; la encore nous n'avons trouve aucune preference des ouvrieres, que la reine leur soit apparentee ou non (figures 3 et 4). Dans une troisieme experience nous avons recherche si les gardiennes a l'entree de la colonie rejetaient les reines physogastriques etrangeres. Pour cela huit reines physogastriques ont ete retirees de leur colonie et immediatement placees a l'entree d'une colonie choisie au hasard et possedant une reine. L'introduction a ete consideree comme reussie lorsqu'au moins trois heures plus tard la reine pouvait etre observee sur le rayon apparemment en bonne sante. Toutes les reines introduites ont ete acceptees. Implications sur le plan de l'evolution: si la possibilite existe de discriminer les reines d'apres des informations genetiques, elle n'est pas utilisee par les ouvrieres presentes dans la colonie.

The Dufour gland is an organ associated to the bee’s female reproductive apparatus [1]. The gland produces mainly hydrocarbons and other organic oxygenated substances that play diverse pheromonal roles according to the bee ecology [2], but often related with reproduction. In eussocial bees its function is unknown, although probably is also involved in reproduction, marking queen’s eggs [3] or indicating the queen reproductive status [4]. In order to throw some more light on the Dufour gland function in eussocial bees, it was done a study on the occurrence, morphology and chemical composition of this gland in workers and queens of Melipona bicolor, a polygynic neotropical stingless bee. The results showed that the Dufour gland was not present in workers. In virgin queens the gland cells showed characteristics of low activity, presenting few basal and apical plasmic membrane invaginations and few organelles in the cytoplasm (Fig. 1). In physogastric queens the gland epithelium was higher and the cells more active than in virgin queens, showing numerous basal plasmic membrane invaginations that formed a labyrinth, which was filled of an electrondense material (Fig. 2) and is involved with taking up substances from the haemolymph. The apical plasmic membrane invaginations were increased and the subcuticular space filled with material produced by the gland cells, which after will make part of the gland lumen secretion. Therefore, by the morphology view point the Dufour gland is more developed in physogastric than in virgin queens, what is in agreement with chemical analysis of the gland secretion, which showed that virgin and physogastric queen differ reasonably. The virgin queen secretion presents only hydrocarbons and the physogastric hydrocarbons and esters (Table I). The present results showed that this gland in M. bicolor is possibly involved in reproduction. According to preliminary bioassays the secretion allows the workers to distinguish the queens reproductive status and help the physogastric queens to recruit workers for the provisioning and oviposition process, known as P.O.P.

Melipona bicolor, an inhabitant of the Atlantic Rainforest, nidifies in hollows of live or dead trees. In order to study thermoregulation of a nest of this species, a temperature data logger was installed inside a hollow tree. After this, an intruder dug a hole, invaded the nest, and probably consumed its honey, pollen and bees, having remained there during three days. Thermal evidence and its behavior allowed the delimitation of a small number of suspects, wich we analized here. The intruder was a small mammal, predominantly nocturnal, that takes shelter in burrows, probably the yellow armadillo (Euphractus sexcinctus). Other evidence, if collected immediately after invasion, could precisely indicate precisely the species. Melipona bicolor, uma habitante de nossa Mata Atlântica, nidifica em ocos de árvores vivas ou mortas. Com a finalidade de estudar a termorregulação de um ninho dessa espécie, um data logger de temperatura foi instalado no interior de um oco de árvore. Depois disso, um intruso cavou o solo, invadiu o ninho e provavelmente consumiu seu mel, pólen e abelhas, tendo ali permanecido durante três dias. Evidência térmica e comportamento permitiram delimitar um número pequeno de suspeitos, os quais analisamos aqui. O intruso foi um pequeno mamífero, predominantemente noturno, que se abriga em tocas, provavelmente o tatu-peludo. Outras evidências, se coletadas imediatamente após a invasão, indicariam exatamente a espécie do intruso.

Background In the America, from Mexico to Argentina, the genus Melipona has a great diversity of species, mainly in the Amazonian region, and a crucial pollination role. It is already well-known the importance of Brazilian stingless bees as pollinators, as well as producers of good honey, pollen, wax and propolis [1]. The present study is about the characterization of the mitochondrial genome of Melipona scutellaris, a Brazilian stingless bee, commonly found in the Northeast Region [2]. At first, the characterization of bees was based mostly on morphological and behavioral criteria. With advances in molecular biology, such visual criteria proved not to be reliable in all cases. Since the mitochondrial genome is well conserved among this animal species, it has been effectively used as a phylogenetic and evolutionary tool. Furthermore, the interaction between mitochondrial and nuclear genomes has important functions in the gene regulation of both [3]. Basically, the mitochondrial genome is about 16 kb long and it is composed approximately of 37 genes, of which there are the two ribosomal subunits (12S and 16S), 22 tRNAs and 13 proteins (three subunits of cytochrome oxidase, cytochrome B, subunits 6 and 8 of ATP synthase and seven subunits of NADH dehydrogenase) and still an A/T repetitive region [1]. In this study, our reference organism is the Melipona bicolor, a stingless bee also found in Brazil.