Abstract In the current study, two euglossine species, Exaerete smaragdina and Eulaema nigrita, a cleptoparasite bee and its host, respectively, were used as models to: (i) access the genetic diversity and population structure of both species, sampled along a wide latitudinal range of Atlantic Forest, where the distribution of El. nigrita and Ex. smaragdina co-occurs; (ii) investigate the evolutionary history of these species through the Atlantic Forest, and in a wider scenario, to examine the evolutionary history of these species across others forest domains. Analyses involved males of El. nigrita and Ex. smaragdina sampled through Brazilian territory, including 19 sites in the Atlantic Forest. Bayesian Skyline Plot (BSP) was used to infer possible climate oscillations on population of both species over time. The BSP revealed stability in effective population size for both species in most of the Plio-Pleistocene period. However, BSP results aligned to the starlike configuration in the haplotype network, neutrality test, and population diversity patterns indicated population expansion of the two species during the late Pleistocene. Our findings suggest areas of potential refugia to the climatic oscillations of the Pleistocene in the Atlantic Forest in the Brazilian states of Espírito Santo for El. nigrita and Pernambuco for Ex. smaragdina.

Abstract The predatory activities of Apiomerus duckei Costa Lima, Seabra & Hathaway, 1951, Apiomerus pilipes (Fabricius, 1787) and Apiomerus luctuosus Costa Lima, Seabra & Hathaway, 1951 (Hemiptera: Reduviidae: Harpactorinae: Apiomerini) on orchid bees (Hymenoptera: Apidae: Apinae: Euglossini) in odoriferous traps in the influence area of Santo Antonio Hydroelectric Power Plant, Rondonia State, Brazil, and of Cosmoclopius annulosus Stal, 1872 (Hemiptera: Reduviidae: Harpactorinae: Harpactorini) on the bee Ceratina rupestris Holmberg, 1884 (Hymenoptera: Apidae: Apinae: Xylocopini: Ceratinina), in an experimental area cultivated with canola in Passo Fundo, Rio Grande do Sul State, Brazil, are recorded by the first time.

Resumen Se registran por primera vez las actividades depredadoras de Apiomerus duckei Costa Lima, Seabra y Hathaway, 1951, Apiomerus pilipes (Fabricius, 1787) y Apiomerus luctuosus Costa Lima, Seabra y Hathaway, 1951 (Hemiptera: Reduviidae: Harpactorinae: Apiomerini) sobre abejas orquídeas (Hymenoptera: Apidae: Apinae: Euglossini) en trampas odoríferas ubicadas en el área de influencia de la Central Hidroeléctrica Santo Antonio (HEP), Estado de Rondonia, Brasil, y de Cosmoclopius annulosus Stal, 1872 (Hemiptera: Reduviidae: Harpactorinae: Harpactorini) sobre la abeja Ceratina rupestris Holmberg, 1884 (Hymenoptera: Apidae: Apinae: Xylocopini: Ceratinina), en un área experimental cultivada con canola en Passo Fundo, Rio Grande do Sul State, Brasil.

Resumen: Antecedentes y Objetivos: La polinización cruzada mediada por abejas euglosinas ha jugado un papel importante en la evolución de rasgos florales complejos en orquídeas, por lo que su estudio denota los procesos de adaptación en sistemas de polinización altamente especializados. En este trabajo se determinó el tiempo de antesis, y despliegue y desarrollo floral; la transición de la función sexual; la identidad y comportamiento de los polinizadores, y rendimiento reproductivo de Gongora galeata en Veracruz, México. Métodos: Se siguió la fenología floral de 25 individuos de Gongora galeata durante dos estaciones de floración (2017-2018) en una localidad, para estudiar su biología reproductiva. Adicionalmente, se observó la transición de la función sexual en la flor en 15 individuos. Resultados clave: Gongora galeata mostró una floración asincrónica, con cerca de 17 flores dispuestas en dos inflorescencias por planta. Los botones florales se desarrollaron tres días antes en 2017 que en 2018. La antesis de la flor fue de 3-4 días, iniciando en fase estaminada. La remoción del polinario desencadenó, pero no determinó, el cambio a la fase pistilada en las flores. Los individuos macho de Euglossa villosa visitaron y polinizaron por mecanismo de deslizamiento las flores de la orquídea. Las abejas visitaron una hora antes las flores de la orquídea en 2017 con respecto a 2018, resultando en un incremento de 70% en la producción de frutos en 2017. Conclusiones: Gongora galeata exhibió cambios en su fenología de floración y la transición de la función sexual de la flor fue un proceso inherente de la planta e independiente de la actividad de Euglossa villosa. Este estudio destaca la importancia de comprender el funcionamiento de los sistemas de polinización especializados ante futuros cambios en el sistema de polinización.

Abstract: Background and Aims: Outcrossing pollination mediated by euglossine bees has played an important role in evolving complex floral traits in orchids, so their study denotes the adaptation processes in highly specialized pollination systems. Anthesis time, floral display size, flower development, transition of sexual function, pollinator identity and behavior, and reproductive output of Gongora galeata were determined in Veracruz, Mexico. Methods: Floral phenology of 25 individuals of Gongora galeata was surveyed during two flowering seasons (2017-2018) in a locality in order to study the reproductive biology of the species. Additionally, sexual function transition in the flower was studied in 15 individuals. Key results: Gongora galeata showed asynchronous flowering, with around 17 flowers arranged in two inflorescences by plant. Floral buds developed three days earlier in 2017 than in 2018. Floral anthesis lasted for 3-4 days, initiating in staminate phase. Pollinaria removal triggered, but did not constrain, the change to pistillate phase in flowers. Male individuals of Euglossa villosa visited and pollinated by slide mechanism the flowers of orchid. The bees visited one hour earlier the flowers of the orchid in 2017 than in 2018, resulting in a 70% increase of fruit production in 2017. Conclusions: Gongora galeata exhibited changes in its flowering phenology and the sexual function transition in the flower was an inherent process on the plant and independent on the activity of Euglossa villosa. This study highlights the importance to understand the functioning of specialized pollination systems in face of future changes in the pollination system.

RESUMO Neste estudo, por meio de uma avaliação rápida, investigamos diferenças na riqueza, abundância, composição de espécies e diversidade beta de abelhas Euglossini em áreas preservadas e áreas alteradas por populações ribeirinhas na Floresta Nacional de Caxiuanã (norte da Amazônia). Nossas hipóteses foram: i) a riqueza de espécies, diversidade, abundância e composição das abelhas Euglossini diferem entre as áreas preservadas e alteradas, uma vez que muitas espécies são intolerantes a pequenos distúrbios antrópicos; e ii) áreas alteradas por populações ribeirinhas apresentam maiores valores de diversidade beta (dissimilaridade de espécies entre locais) do que áreas preservadas, devido às mudanças locais no habitat e aumento da heterogeneidade entre locais. Amostramos duas áreas (preservadas e alteradas) e, em cada área, foram amostrados quatro transectos com iscas odoríferas. Nós utilizamos testes t de Student, para avaliar diferenças de riqueza, abundância e índice de diversidade de Shannon-Wiener. Também avaliamos as diferenças na composição e as diferenças na diversidade beta entre as áreas. Foram coletados 102 espécimes, em 18 espécies e três gêneros, 63 deles (61,8%) em áreas preservadas e 39 (38,2%) em áreas alteradas. Euglossa liopoda (Dressler, 1982) foi a mais abundante nas áreas alteradas e Euglossa imperialis (Cockerell, 1922) nas áreas preservadas. A riqueza foi 2,5 vezes maior nos transectos de áreas preservadas, e a composição de espécies também diferiu entre as áreas amostradas. Em contraste, a abundância de espécies não foi diferente entre os transectos das duas áreas. Apesar de nosso esforço amostral reduzido, nossos resultados demonstram que a riqueza, composição e diversidade beta das abelhas Euglossini podem potencialmente ser afetadas por mudanças locais no habitat causadas por atividades de pequena escala fornecidas por grupos tradicionais da Amazônia. Esses resultados indicam a urgência por estudos mais extensos no sentido de investigar as relações aqui estudadas.

ABSTRACT In this study, through a rapid assessment, we evaluated differences in richness, abundance, species composition and beta diversity of Euglossini bees in preserved areas and areas altered by riverine human populations in the Caxiuanã National Forest (northern Amazon). Our hypotheses were: i) the species richness, diversity, abundance and composition of Euglossini bees differ between the preserved and altered areas because many species are intolerant to small anthropic disturbances; and ii) areas altered by riverine populations have higher values of beta diversity (species dissimilarity between sites) than preserved areas, due to local changes in habitat and increased heterogeneity between sites. We sampled two areas (preserved and altered) and, in each area, four transects were sampled with odorous baits. We used a Student’s t test to evaluate differences in richness, abundance, and Shannon-Wiener diversity index. We also evaluated differences in composition and differences in beta diversity between areas. We collected 102 specimens, identified in 18 species and three genera, 63 individuals (61.8% of the total) in preserved areas and 39 individuals (38.2%) in altered areas. Euglossa liopoda (Dressler, 1982) was the most abundant in altered areas and Euglossa imperialis (Cockerell, 1922) the most abundant in preserved areas. Species richness was 2.5 times greater in the transects of preserved areas, and species composition also differed between the sampled areas. In contrast, species abundance did not differ between transects of both areas. Despite our small sample size, this study demonstrated that the richness, composition and beta diversity of Euglossini bees can be potentially affected by local changes in habitat caused by small-scale activities provided by traditional Amazonian groups. Our results indicate the urgency for more comprehensive studies aimed to investigate these relationships.

ABSTRACT Male euglossine bees (Euglossine: Apidae) pollinate flowers of as many as 1,000 Neotropical plant species and there is evidence that blooming in these plants is synchronized with the seasonality of euglossine pollinators. The present study aimed to monitor for two years the phenology of Sarcoglottis acaulis (Orchidaceae - Spiranthinae subtribe) and the seasonality of its pollinators at three Atlantic Forest fragments, two of which surrounded by urban anthropized areas. Phenologies in the three areas were related to abiotic factors, suggesting that precipitation on months prior to the beginning of the flowering period influenced the fructification rates of S. acaulis. Additionally, water shortage during the driest months resulted in vegetative dormancy. Sarcoglottis acaulis sets only a low number of fruits by self-pollination, and the plant’s reproductive success depended on the frequency of its main pollinator, i.e., the male euglossine bees Eulaema atleticana. Lower rates of pollinia removal were observed in areas where this bee is less frequent and, consequently, less fruits were formed, suggesting a high dependency on this pollinator.

RESUMO As florestas ripárias no Brasil são importantes ecossistemas que sustentam uma enorme biodiversidade. Apesar de protegidas pela legislação brasileira, elas têm sofrido grandes impactos decorrentes da fragmentação florestal. As abelhas das orquídeas constituem um grupo chave de polinizadores na região Neotropical, porém, pouco se sabe sobre suas assembleias em florestas ripárias. Nós avaliamos o papel de fragmentos de floresta ripária e de terra-firme na conservação e manutenção da fauna de abelhas das orquídeas em uma paisagem urbana no sudoeste da Amazônia. Especificamente, avaliamos se assembleias de abelhas de fragmentos ripários e de terra-firme diferem significativamente em abundância, riqueza e composição de espécies. Também avaliamos se a abundância e a riqueza de espécies variam em função do tamanho do fragmento. Machos de abelhas foram atraídos por iscas odoríferas e coletados com redes entomológicas em 10 fragmentos florestais. Não houve diferença significativa entre fragmentos ripários e de terra-firme quanto à abundância, riqueza e composição de espécies, mas houve uma correlação positiva entre o tamanho do fragmento e a riqueza e abundância de espécies. Nossos resultados sugerem que, em uma paisagem urbana, os fragmentos de floresta ripária e de terra firme ainda podem manter 62,7% do número de espécies de abelhas das orquídeas conhecido para a região, reforçando o valor da conservação desses remanescentes florestais. Nossos dados indicam que esses fragmentos fornecem um habitat potencialmente importante para a manutenção das populações locais de abelhas na paisagem.

ABSTRACT Riparian forests are important ecosystems that support an enormous biodiversity in Brazil. Despite being protected under Brazilian legislation, these forests suffer great impact from the fragmentation of habitats. Orchid bees are a key group of pollinators in the Neotropical region, yet few data are available on the assamblage structure of these bees in riparian forests. We evaluated the role of fragments of riparian and terra-firme forest on the conservation and maintenance of orchid bees in an urban landscape in the southwestern Amazon basin. Specifically, we evaluated whether bee assemblages in riparian and terra-firme forests differed significantly in abundance, species richness and composition. We also evaluated whether species richness and abundance of bees vary with the size of the forest fragment. Male bees were attracted using odoriferous baits and collected with entomological nets in 10 forest fragments. There was no significant difference between riparian and terra-firme fragments in species abundance, richness and composition, but there was a positive correlation between fragment size and species richness and abundance. Our results suggest that, in an urban landscape, the remaining riparian and terra-firme forest fragments still could maintain 62.7% of the orchid bee species known to occur in the region, reinforcing the conservation value of these forest remnants. Our findings indicate that these fragments provide a potentially important habitat for the maintenance of local bee populations in the landscape.

Resumen En este documento presentamos una actualización de la información concerniente al género Eufriesea para Colombia. Se describe la hembra de Eufriesea dressleri (Kimsey, 1977), que era la única hembra del grupo elegans aún no descrita. Se propone una clave taxonómica para su identificación y se extiende el rango de distribución de Eufriesea dressleri, Eufriesea concava, Eufriesea magretti y Eufriesea pulchra para Colombia, incluidos nuevos registros altitudinales.

Abstract In this paper, we present an update of the information concerning the genus Eufriesea for Colombia. We describe the female Eufriesea dressleri (Kimsey, 1977), the only female of the elegans group not yet described. A taxonomic key is proposed for its identification and the range of distribution of Ef. dressleri, Eufriesea concava, Eufriesea magretti, and Eufriesea pulchra is extended for Colombia including new altitudinal records.

ABSTRACT Oncidiinae is an exclusively Neotropical orchid subtribe with about 1600 described species and an impressive array of vegetative and floral morphological adaptations. We present the results of a literature survey on the pollination strategies and breeding systems of this orchid subtribe. The flowers are pollinated by a wide range of insects (mostly bees) and, sometimes, hummingbirds. Several genera reward their pollinators with floral resources such as oils, nectar or perfumes. Whereas pollination by oil-gathering bees likely evolved several times within Oncidiinae, exclusive pollination by perfume-gathering male Euglossine bees is likely restricted to a set of closely-related genera. Pollination by food or sexual deception is also present within the subtribe. Up to date, the pollen-vectors of the 92 species of Oncidiinae studied so far are as follows: 84.7 % are pollinated by bees, 6.5 % by wasps, 4.3 % by hummingbirds, 3.2 % by butterflies and 3.2 % by flies. Oncidiinae orchids are preferentially self-incompatible (69.4 % of the species studied so far), some may also present protandry as a mechanism to promote cross-pollination. Fruiting success is generally low. The rate of visitation with subsequent pollination is low, in general, which contributes to the low reproductive success of this plant group.

Resumo A distribuição da maioria das espécies ocorre em regiões delimitadas com características únicas conhecidas como “centros de endemismo”. Na Amazônia Oriental está localizado o Centro de Endemismo Belém (CEB), uma das áreas mais intensivamente desmatadas na Amazônia Brasileira. Aqui, apresentamos informações sobre assembleias de abelhas orquídeas baseadas em registros históricos de coleções entomológicas. Para cada espécie, foram calculadas a frequência de ocorrência e a dominância, classificando-as em 3 estados: espécies comuns, intermediárias ou raras. Foram geradas curvas de riqueza observada e estimada, com base no estimador Jackknife. Encontramos 1.257 espécimes de 56 espécies, constituindo registros de 1917 a 2009, e uma espécie é um novo registro no CEB. Maior número de espécimes e espécies foi concentrado em poucos locais, com intensificação nas coletas a partir dos anos70. Os resultados sugerem alta riqueza de abelhas orquídeas no CEB, embora esse cenário esteja longe do que é esperado para toda a área. A elevada ocorrência de espécies raras pode estar relacionada à baixa representatividade nas coleções e a proximidade entre as áreas favoreceu as amostragens. Mesmo assim, a lista de espécies e o estado de conservação aqui apresentados podem ser informações úteis em estudos interessados em comparar a fauna passada e atual de abelhas das orquídeas e, aliado a dados sobre as respostas das abelhas às mudanças de uso da terra ocorridas no CEB ao longo dos anos, podem servir de base para definição de áreas prioritárias para conservação.

Abstract The distribution of most species occurs in delimited regions with unique characteristics called “centers of endemism”. In Eastern Amazon is located the Belém Endemism Center (BEC), one of the most intensely deforested in Brazilian Amazon. Here, we show information about orchid bee assemblages based on historical records from entomological collections. For each species, we calculated occurrence frequency and dominance, and we classified them in 3 statuses: common, intermediate or rare species. Curves of observed and estimated richness were built, based on Jackknife estimator. We found 1,257 specimens from 56 species, constituting records from 1917 to 2009, and one species is a new record for BEC. Higher number of specimens and species was concentrated in a few locations and surveys increased from the 70’s. The results suggest a high richness of orchid bees in the BEC, although this scenario is far from what is expected for the entire area. The high occurrence of rare species may be related to their low representativeness in the collections, and the proximity between the areas had favored samplings. Even so, the species list and the conservation status presented here may be useful information in studies comparing past and current orchid bee fauna, and, allied to data on bees’ responses to land use changes occurred in BEC over the years, can fit as a basis for defining priority areas for conservation.

ABSTRACT Bait traps are effective and commonly used method in the studies of orchid bees. Important questions in the context of this method, including those related to bait dispersion, how long baits remain attractive, the distance from which males are supposed to be attracted to lures and so on, are still open subjects. Data on the attractiveness of bait traps that have remained in the field during two weeks in a large Atlantic forest preserve are presented. Four main results emerge from the data: (i) the abundance of specimens collected per day decreased in all the attractants as the traps were left on the field; (ii) despite this decrease, the absolute number of individuals collected after eight and fifteen days is remarkably, mostly in eugenol and vanillin baits; (iii) the vast majority of species, 22 of 25, was already collected on the first sample day; (iv) a consistent variation in the relative abundance of individuals collected in each scent as collections were made. We urge that bait traps should not be left in the field beyond what is strictly necessary since there is a real possibility of collecting a significant number of individuals as these traps remain available.

RESUMO Abelhas Euglossa Latreille, 1802 não vivem em grandes colônias, e estas geralmente são mantidas ou “reativadas” por novas fêmeas, subordinadas à mãe, que constroem e fornecem células de cria. Este estudo teve como objetivo obter informações sobre o tempo que as abelhas levam para prover novas células, sobre a emergência e permanência das abelhas nos ninhos, bem como o número de ninhos construídos por cada uma. Durante sete meses observamos fêmeas em 14 caixas vazias de madeira (5,7 x 5,7 x 7,0 cm), disponibilizadas para nidificação das abelhas. O método de remarcação foi utilizado quando uma abelha foi encontrada pela primeira vez nas caixas ou para cada nova abelha filha após a sua emergência. Um total de 12 caixas foi colonizada por Euglossa cordata (Linnaeus, 1758) e 23 células foram construídas em 9,78 ± 11 dias por célula. Onze fêmeas emergiram das células em 48,6 ± 11 dias. Dois imaturos morreram e dois foram parasitados por Bombyliidae. Apesar de que as fêmeas adultas de E. cordata moveram-se entre ninhos e às vezes usaram vários ninhos de uma só vez, elas demonstraram uma fidelidade relativamente alta a um único ninho (81.1% dessas fêmeas permaneceram mais de 50% do tempo em um único ninho).

ABSTRACT Euglossa Latreille, 1802 do not live in large colonies, and these are usually maintained or “reactivated” by new females, subordinate to their mother, which construct and provision brood cells. This study aimed to obtain information about the natural history of Euglossa cordata (Linnaeus, 1758) specially focusing on nest behavior. Our specific objective was to answer the following question: do E. cordata females reside in a single nest? We construct 14 artificial nesting boxes and made them available for E. cordata bees in natural environment for seven months. During this time, we use a re-marking method to identify bee fidelity to a single nest box. More specifically, we record bee permanence in the nests, the time bees take to provision brood to new cells and the time taken to offspring emergence. A total of 12 boxes were colonized by E. cordata and 23 cells were built in an average of 9.78 ± 11 days per cell. Eleven females emerged from the cells in 48.6 ± 11 days. Although adult females moved between nests and sometimes used multiple nests at the same time, E. cordata showed a relatively high fidelity to a single nest (81.1% of the female bees stayed in a single nest more than 50% of time).

Abstract Seasonal fluctuations in the abundance of orchid bees have already been reported. The variations in population dynamics may be expected to occur in more predictable and pronounced manners in environments with a clear distinction between rainy and dry seasons, where climatic variables are regarded to be good predictors of populational patterns. The main goal of this paper is to investigate the seasonality of males of orchid bees in fragments of Seasonal Semideciduous Forest in southern Brazil. Data comprise bait samples from five one-year periods on four forest fragments. The seasonality of species abundance was tested with circular statistics. Results suggest two phenological patterns, one for Eufriesea violacea (Blanchard), Eulaema nigrita Lepeletier and Euglossa cordata (Linnaeus), whose abundances are concentrated in late spring and early-middle summer and another for Euglossa fimbriata Moure with a tendency to be collected in middle-late summer and early autumn. These patterns are discussed, as well the possible driven factors, (i) the species life cycle and nesting behavior, (ii) synchrony with resource, and (iii) climate. We can postulate an important impact of climate change in local euglossine assemblage due to the small populations and marked seasonality.

Resumo: Abelhas-das-orquídeas foram amostradas no Parque Nacional do Iguaçu, o maior fragmento de Floresta Estacional Semidecidual do Brasil. Sete espécies foram coletadas e Eufriesea violacea (Blanchard) foi a espécie mais comum, seguida por Euglossa annectans Dressler. A riqueza e composição de espécies observadas concordam com o que se conhece para as faunas locais de abelhas euglossinas em fragmentos de Floresta Estacional Semidecidual. Por outro lado, a abundância de indivíduos foi notavelmente baixa. A ocorrência de um inverno severo em 2013 e a coleta de muitos machos em outros fragmentos sugerem que tal baixa abundância pode ser fortuita.

Abstract: Orchid bees were surveyed at Parque Nacional do Iguaçu, the largest remnant of Seasonal Semideciduous Forest in Brazil. Seven species were collected, and Eufriesea violacea (Blanchard) was the most common species, followed by Euglossa annectans Dressler. The observed species richness and species composition agree with what is known for the local euglossine faunas in fragments of Seasonal Semideciduous Forest of southern and southeastern Brazil. On the other hand, the abundance of individuals was remarkably low. The occurrence of a severe winter in 2013 and the collection of several males in other fragments suggest that this noteworthy low abundance can be fortuitous.

AbstractCatasetum is a neotropical orchid genus of 130 species characterized by its unisexual flowers. They are pollinated by male Euglossini bees. It is widely know that these bees collect volatile compounds in Catasetum from structures called osmophores. However, there is little information on morpho-anatomy and histochemistry of secretory tissues for this neotropical genus and data are lacking. Based on these arguments members of the Catasetum cristatum alliance, namely C. arietinum, C. ariquemense, C. barbatum, C. carolinianum, C. cristatum, C. lanciferum, C. multifidum, C. multifissum, C. rivularium and C. semicirculatum were analyzed. The labellum of male flowers of this alliance is elongate and with fimbriate margins, possessing two protuberances and a median saccate portion. The labellum of female flowers is galeiform and there is no ornamentation. The entire adaxial surface of the labellum is secretory in both sexes, including the fimbriae of male flowers. The structure of the secretory tissue is similar among species, and they are composed of a simple epidermis and five layers of underlying parenchyma. In most species the epidermis is flat, and cells are elongated in the saccate portion. In C. ariquemense and C. carolinianum the epidermal cells are papillous, while in C. semicirculatum they have convex surface (male flowers). The histochemical analysis detected lipophilic droplets and starch grains inside the secretory cells. All characteristics observed are encountered in secretory tissues with high-energy demand, as is common in osmophores.