Overlap of Ecological Niche Breadth of Euglossa cordata and Eulaema nigrita (Hymenoptera, Apidae, Euglossini) Accessed by Pollen Loads and Species Distribution Modeling.

Urban areas can serve as biodiversity refuges for pollinators because of the high diversity of available floral and nesting resources. However, it remains unclear what plant species commonly used for urban landscaping provide floral resources that pollinators actively use. Here, we integrate data from the pollen and species distribution models of two abundant euglossine bees-the large-bodied Eulaema nigrita (Lepeletier, 1841) and the small-bodied Euglossa cordata (Linnaeus, 1758)-in urban areas to investigate their overlap in diet breadth and distribution. We hypothesized that because bees with larger body sizes tend to have larger foraging areas, large-bodied bees would have a wider diet breath than small-bodied bees. Contrary to our hypothesis, we found that Eg. cordata has a wider diet breadth than El. nigrita with the former species showing higher diversity of pollen types collected (per pollen load and on average across pollen loads). Pollen grains from Solanum paniculatum and Tradescantia zebrina represented 63% of the diet of Eg. cordata, whereas pollen from S. paniculatum and Psidium guajava represented 87% of the diet of El. nigrita. After overlaying the distribution of both bee species and the three most important pollen resources, the distribution models revealed that these three plant species can co-occur with both euglossine bees throughout a large portion of eastern Brazil near the coast. Thus, we conclude S. paniculatum, T. zebrina, and P. guajava should be considered key plants for the maintenance of these two urban euglossine bee species. The results of this study provide important information for urban landscaping programs that aim to protect and preserve pollinators.

Geographical origin of white honey produced by stingless bees in the Araucaria Forest in Southern Brazil / Origem geográfica do mel branco produzido por abelhas sem ferrão na Floresta de Araucárias no Sul do Brasil

Abstract: Honey produced by native stingless bees in the Araucaria Forest region of Rio Grande do Sul, southern Brazil, specifically the municipality of Cambará do Sul, is highly valued for its characteristic white color, floral odor and taste. In this study, we investigated the botanical origin of white honey stored in colonies of five Meliponini species of the genera Melipona (n = 3) and Plebeia (n = 2). During the production period of white honey, from January to March, flowers were sampled fortnightly along pre-established trails to identify plants used by bees. For all sampled plant species, exsiccates and pollen reference slides were prepared. Honey samples from stingless bees were processed for extraction and preparation of pollen grains for identification of pollen types. In all analyzed honey samples, pollen grains of Clethra scabra (Clethraceae) were predominant (between 46-94%). Pollen grains from other botanical families, including Myrtaceae, Fabaceae and Melastomataceae were frequently identified in honey samples of the Melipona species, while Cunoniaceae was also found in samples of Plebeia species. In this study, we concluded that Clethra scabra is predominantly used by Meliponini bees in the production of white honey in the municipality of Cambará do Sul.

Resumo: Na região da Floresta de Araucária do Rio Grande do Sul, especificamente no município de Cambará do Sul, as abelhas nativas sem ferrão produzem mel característico devido à sua cor branca e gosto apreciado. Neste estudo, investigamos a origem botânica do mel branco armazenado em colônias de cinco espécies de Meliponini dos gêneros Melipona (n = 3) e Plebeia (n = 2). Durante o período de produção do mel branco, de janeiro a março, as flores foram amostradas quinzenalmente ao longo de trilhas pré-estabelecidas, a fim de identificar as espécies utilizadas pelas abelhas. A partir de amostras de plantas foram preparadas exsicatas e lâminas de referência de pólen. As amostras de mel de abelhas sem ferrão foram processadas para extração e preparo dos grãos de pólen para a determinação dos tipos polínicos presentes. Em todas as amostras de méis branco analisadas os grãos de pólen de Clethra scabra (Clethraceae) predominaram (entre 46-94%). Grãos de pólen de outras espécies das famílias botânicas Myrtaceae, Fabaceae e Melastomataceae foram frequentemente identificados nas amostras de méis das espécies de Melipona, enquanto Cunoniaceae também o foi nas amostras das espécies de Plebeia. Neste estudo, nós concluímos que Clethra scabra é predominantemente utilizada pelas abelhas Meliponini na produção de méis branco no município de Cambará do Sul.

Nocturnal floral scent profiles of Myrtaceae fruit crops.

Communication between plants and nocturnal pollinators in low light conditions is mainly guided by floral scents, which is well documented for plants pollinated by bats, moths, and beetles. Just recently, nocturnal bees have been added to the list of pollinators known to respond to floral scents of their host plants. Little is known about the floral scent chemistry of plants visited and pollinated by nocturnal bees. Among these plants are economically important fruit crops of the family Myrtaceae. We aimed to analyze the nocturnal floral scent profiles of 10 species of Myrtaceae (only diurnal P. cattleianum was sampled after sunrise) and address the following questions: i) What are the main floral scent compounds emitted by the species? ii) Are the floral scent profiles similar to those described for other species pollinated by nocturnal bees? Floral scents were collected by dynamic headspace and analyzed by GC-MS (gas chromatography - mass spectrometry). The total amount of scent trapped ranged from 74 ng/flower/hour for Syzygium malaccense to 7556 ng/flower/hour for Eugenia dysenterica. A total of 46 floral scent compounds were detected in the samples with the most abundant compounds being the aromatics benzaldehyde, benzyl alcohol, 2-phenylethanol, methyl salicylate, 2-phenylethyl acetate, and benzyl acetate; the aliphatic compound 1-octanol; and the monoterpene linalool. The different species exhibited different relative scent patterns. Overall, the nocturnal scents of the studied species of Myrtaceae are dominated by aromatic compounds, which is in contrast to the scent profiles described for other plants pollinated by nocturnal bees.

Osmophores of Caryocar brasiliense (Caryocaraceae): a particular structure of the androecium that releases an unusual scent.

Caryocar brasiliense is a flagship species of the Brazilian Cerrado. It produces flowers with a strong peculiar scent, which are pollinated by bats and occasionally moths with short mouthparts. However, the cues responsible for attracting these nocturnal pollinators remain unknown. We aimed to identify osmophores of C. brasiliense, describe the ultrastructure of the cells involved in the synthesis and release of floral odour, and identify the constituents of the floral bouquet. We performed field observations and histochemical and ultrastructural analyses of flowers focusing on the androecium. Gas chromatography-mass spectrometry was used to analyse the scents emitted. Filament epidermal cells were found to possess an unusual shape and be responsible for the main production and release of odour. These cells, called foraminous cells, are elongate and possess pores where their cell walls are abruptly thin. The cuticle is practically absent over the pores, which facilitates odour emission. The foraminous cells have conspicuous nuclei and organelle-rich cytoplasm where oil droplets can be seen prior to anthesis. The features of these cells remain similar during anthesis, but many vesicles fuse with the plasma membrane and the number of oil droplets in the cytosol decreases. Twenty-nine components were found in the scent, especially fatty acid derivatives and N- and S-bearing compounds. Our analyses revealed that the androecium of C. brasiliense has a particular structure that acts as an osmophore. The scent from the androecium resembles that of the entire flower, which is an unprecedented finding for a plant with single flowers as the pollination unit.

Modificação da via aérea superior com uso de CPAP: avaliação por faringometria acústica em apnéicos graves e roncadores simples / Upper airway reconfiguration with CPAP: acoustic pharyngometry evaluation in severe apneics and simple snorers

Introdução: A Apneia Obstrutiva do Sono (AOS) é uma doença crônica e evolutiva que tem uma alta prevalência e pode acarretar graves repercussões hemodinâmicas, neurológicas e comportamentais. A pressão positiva contínua na via aérea (CPAP) é altamente eficaz no tratamento da AOS, porém o processo de expansão da faringe por este dispositivo não é totalmente entendido. A faringometria acústica (FA) é um método de mensuração das dimensões da cavidade oral e da faringe, reprodutível e fácil de efetuar, podendo avaliar eficientemente os efeitos do CPAP na faringe e trazer informações sobre sua complacência e sítios de obstrução. Objetivo: avaliar as mudanças induzidas pelo CPAP nas dimensões da faringe e no posicionamento do palato mole em pacientes com AOS e verificar se a deformabilidade da via aérea superior pelo CPAP é maior em apneicos graves do que em roncadores simples. Desenho do estudo: estudo prospectivo. Métodos: 48 pacientes foram submetidos a FA durante o uso do CPAP. 29 pacientes com índice de apneia e hipopneia (IAH) >30 e indicação de uso do CPAP foram inclusos no grupo AOS, e 19 pacientes com IAH <=5 foram inclusos no grupo controle. Os critérios de inclusão foram: idade entre 18 e 65 anos, ambos os sexos, polissonografia (PSG) previamente realizada, e PSG para titulação do CPAP no grupo AOS. Os critérios de exclusão foram: obstrução nasal crônica pré existente, uso de medicamentos psiquiátricos, neurológicos ou miorrelaxantes, insuficiência cardíaca congestiva, índice de massa corpórea >= 35 e cirurgia palatal prévia para AOS. Os gráficos resultantes dos exames de FA foram analisados por 2 examinadores cegos que marcaram os pontos para obtenção da distância da transição orofaríngea da glote. Foram calculados também o comprimento e o volume da faringe pelo programa do aparelho. Foi então feita a análise estatística para comparar as medidas em diferentes pressões intragrupo e intergrupo. Resultados: As medidas dos dois examinadores mostraram...

Rationale: Obstructive Sleep Apnea (OSA) is an evolutive disease, with a high prevalence, that can cause serious hemodynamic, neurological and behavioral repercussions. Continuous positive airway pressure (CPAP) is highly effective in OSA treatment, however the pharynx expansion by this advice is not fully understood. Acoustic pharyngometry (AP) is a measurement method of oral cavity and pharynx dimensions, and can efficiently evaluate CPAP effects on pharynx, bringing informations about its compliance and sites of obstruction. Objectives/Hypothesis: To verify if the CPAP-induced deformability on the pharynx and soft palate is greater in obstructive sleep apnea (OSA) patients than in simple snorers. Study Design: Prospective study. Methods: 29 patients with severe OSA and 19 simple snorers underwent acoustic pharyngometry measurements while awake in supine position. Measurements were first made without CPAP, and then with a nasal CPAP starting with 4cmH2O and up to 10cmH2O. The oropharyngeal transition and the position of the glottis were marked in the generated curves by two blinded examiners. The marked values were averaged to calculate the oropharyngeal transition and the pharyngeal length and volume under zero, 4 and 10cmH2O of CPAP for each group. Results: CPAP did not produce any significant enlargement in the pharyngeal airway nor changed the soft palate positioning in both groups. At baseline, OSA patients have a longer pharynx than simple snorers. After the application of CPAP, there was no difference in the length and volume of the pharynx between groups. Conclusions: There were no significant differences in the position of oropharyngeal junction and glottis between snorers and apneics with CPAP appliance. There was no significant expansion in pharyngeal airway with CPAP appliance in snorers and apneics. Anatomically, apneics presented a longer superior airway than simple snorers.

The importance of plant diversity in maintaining the pollinator bee, Eulaema nigrita (Hymenoptera: Apidae) in sweet passion fruit fields

The euglossine bee Eulaema nigrita plays an important role for the pollination of native and economically important plants, such as the sweet passion-fruit Passiflora alata. E. nigrita uniquely collects the nectar from the flowers of P. alata, nevertheless, it needs to visit other plants to collect pollen, nectar and other resources for its survival. There are two methods to identify the species of plants used by bees in their diet: by direct observation of the bees in the flowers, and through identification of pollen grains present in brood cells, feces, or in the bees’ body. In order to identify the other plants that E. nigrita visits, we analyzed samples of pollen grains removed from the bee’s body in the course of the flowering period of P. alata. Among our results, the flora visited by E. nigrita comprised 40 species from 32 genera and 19 families, some of them used as a pollen source or just nectar. In spite of being a polyletic species, E. nigrita exhibited preference for some plant species with poricidal anthers. P. alata which has high sugar concentration nectar was the main source of nectar for this bee in the studied area. Nonetheless, the pollinic analysis indicated that others nectariferous plant species are necessary to keep the populations of E. nigrita. Studies such as this one are important since they indicate supplementary pollen-nectar sources which must be used for the conservation of the populations of E. nigrita in crops neighbouring areas. In the absence of pollinators, growers are forced to pay for hand pollination, which increases production costs; keeping pollinators in cultivated areas is still more feasible to ensure sweet passion fruit production.

La abeja euglosina Eulaema nigrita juega un importante papel para la polinización de las plantas nativas y de importancia económica, como es el caso de la fruta de la pasión o maracuyá Passiflora alata. E. nigrita únicamente recoge el néctar las flores de P. alata, sin embargo, tiene que visitar otras plantas para recoger polen, néctar y otros recursos para su supervivencia. Hay dos métodos para identificar las especies de plantas utilizadas por las abejas en su dieta: por observación directa de las abejas en las flores, y a través de la identificación de los granos de polen presentes en las celdas de cría, heces o en el cuerpo de las abejas. Con el fin de identificar las otras plantas que E. nigrita visita, se analizaron muestras de granos de polen extraído del cuerpo de la abeja durante el período de floración de P. alata. Entre nuestros resultados, la flora visitada por E. nigrita está compuesta por 40 especies de 32 géneros y 19 familias, algunas de ellas utilizadas como fuente de polen o solamente de néctar. A pesar de ser una especie polifilética, E. nigrita exhibe preferencia por algunas especies de plantas con anteras poricidas. El néctar de P. alata tiene la más alta concentración de azúcar y fue la principal fuente de este recurso para las abejas en el área de estudio. Sin embargo, el análisis polínico indicó que otras especies de plantas nectaríferas son necesarias para mantener las poblaciones de E. nigrita. Estudios como éste son importantes pues indican cuales son las fuentescomplementarias de néctar y polen que deben ser utilizadas para la conservación de las poblaciones de E. nigrita en los cultivos de las zonas vecinas. En ausencia de polinizadores, los productores se ven obligados a pagar por la polinización manual, lo que aumenta los costos de producción, por lo tanto el mantenimiento de polinizadores en las zonas cultivadas es más factible para asegurar la producción de la fruta de la pasión.

The importance of plant diversity in maintaining the pollinator bee, Eulaema nigrita (Hymenoptera: Apidae) in sweet passion fruit fields.

The euglossine bee Eulaema nigrita plays an important role for the pollination of native and economically important plants, such as the sweet passion-fruit Passiflora alata. E. nigrita uniquely collects the nectar from the flowers of P. alata, nevertheless, it needs to visit other plants to collect pollen, nectar and other resources for its survival. There are two methods to identify the species of plants used by bees in their diet: by direct observation of the bees in the flowers, and through identification of pollen grains present in brood cells, feces, or in the bees' body. In order to identify the other plants that E. nigrita visits, we analyzed samples of pollen grains removed from the bee's body in the course of the flowering period of P. alata. Among our results, the flora visited by E. nigrita comprised 40 species from 32 genera and 19 families, some of them used as a pollen source or just nectar. In spite of being a polyletic species, E. nigrita exhibited preference for some plant species with poricidal anthers. P. alata which has high sugar concentration nectar was the main source of nectar for this bee in the studied area. Nonetheless, the pollinic analysis indicated that others nectariferous plant species are necessary to keep the populations of E. nigrita. Studies such as this one are important since they indicate supplementary pollen-nectar sources which must be used for the conservation of the populations of E. nigrita in crops neighbouring areas. In the absence of pollinators, growers are forced to pay for hand pollination, which increases production costs; keeping pollinators in cultivated areas is still more feasible to ensure sweet passion fruit production.

Colesteatoma primário de meato acústico externo bilateral / Primary cholesteatoma of the bilateral external acoustic meatus

Introdução: O colesteatoma de meato acústico externo é uma patologia rara. A maioria das séries na literatura descreve casos secundários, com poucos relatos de colesteatoma primário. Caracteriza-se pela erosão da porção óssea do meato acústico externo por proliferação de tecido escamoso adjacente. Objetivo: Relatar um caso raro de colesteatoma primário de meato acústico externo bilateral. Relato do Caso: Paciente de 20 anos, sexo feminino, com otalgia há 3 anos, associada à hipoacusia e otorreia à esquerda. Sem história prévia de patologias otológicas. À otoscopia, observava-se erosão bilateral do meato acústico externo com grande quantidade de debris epidérmicos. A tomografia computadorizada evidenciou colesteatoma de meato acústico externo bilateral, sendo a paciente submetida à timpanomastoidectomia radical modificada à direita. Comentários Finais: O colesteatoma primário de meato acústico externo é uma patologia rara, fazendo parte do diagnóstico diferencial de otalgia e otorreia crônicas. A avaliação da sua extensão deve ser feita com tomografia computadorizada e o tratamento de eleição é a cirurgia.

Introduction: The cholesteatoma of the external acoustic meatus is an uncommon pathology. Most series in the literature describe secondary cases, with a few reports of primary cholesteatoma. It is characterized by the erosion of the external acoustic meatus bone portion by proliferation of the adjacent squamous tissue. Objective: To report an uncommon case of primary cholesteatoma of the bilateral external acoustic meatus. Case Report: Female patients aged 20 years old with ear ache for 3 years, associated to hypacusis and otorrhea to the left. Without a previous history of otologic pathologies. Upon otoscopy, there could be noticed bilateral erosion from the external acoustic meatus with a large amount of epidermal debris. The computed tomography confirmed cholesteatoma of the bilateral external acoustic meatus and the patient was submitted to modified radical tympanomastoidectomy to the right. Final Comments: The primary cholesteatoma of the external acoustic meatus is an uncommon pathology that is part of the differential diagnosis of chronic otalgia and otorrhea. The evaluation of its extension must be done with computed tomography and surgery is the choice treatment.

Competição entre abelhas durante forrageamento em Schefflera arboricola (Hayata) Merr / Competition among bees during foraging on Schefflera arborícola (Hayata) Merr

Schefflera arboricola (Hayata) Merr (Araliaceae) é uma planta exótica, porém amplamente cultivada no Brasil para ornamentação. Devido à abundância de flores que produz, esta árvore é altamente atrativa para abelhas Apis mellifera, bem como para diversos meliponíneos nativos. S. arboricola oferece aos seus visitantes florais pólen e néctar, que são disponibilizados ao amanhecer. A. mellifera possui ampla vantagem na coleta desses recursos devido à sua capacidade de forragear mais cedo do que os meliponíneos de pequeno e médio porte. Através de experimentos de exclusão verificou-se que as abelhas nativas mudam seu comportamento nas flores de S. arboricola em função da competição. Quando A. mellifera compete pelos mesmos recursos florais, as abelhas Scaptotrigona visitam três vezes mais flores e mudam o recurso preferencialmente coletado, pois passam a coletar pólen ao invés de néctar. Os dados obtidos sugerem que A. mellifera pode estar interferindo na dinâmica de forrageamento das abelhas Scaptotrigona.

Schefflera arboricola Hayata Merr (Araliaceae) is an exotic plant widely cultivated in Brazil for ornamental purposes. Their flowers are very attractive to Africanized honey bees (Apis mellifera) as well to several native Meliponini bees. Therefore, it is an interesting plant to test the competitive interactions and foraging overlapping among Africanized honey bees and native stingless bees. S. arboricola offers pollen and nectar to their visitors, which become available early, in the morning. A. mellifera has a large advantage in resource harvesting since can forage earlier than smaller stingless bees. By means of an exclusion experiment, it was verified that the behaviors of native bees change when they are visiting S. arboricola’s flowers in the presence of A. mellifera. When Scaptotrigona and A. mellifera are partitioning this flower resource, Scaptotrigona bees visited three times more flowers and changed the resource preference from nectar to pollen. In this context, A. mellifera may be interfering in the foraging dynamics of native Scaptotrigonabees.