Effects of landscape, resource use, and body size on genetic structure in bee populations.

Quantifying genetic structure and levels of genetic variation are fundamentally important to predicting the ability of populations to persist in human-altered landscapes and adapt to future environmental changes. Genetic structure reflects the dispersal of individuals over generations, which can be mediated by species-level traits or environmental factors. Dispersal distances are commonly positively associated with body size and negatively associated with the amount of degraded habitat between sites, motivating the investigation of these potential drivers of dispersal concomitantly. We quantified genetic structure and genetic variability within populations of seven bee species from the genus Euglossa across fragmented landscapes. We genotyped bees at SNP loci and tested the following predictions: (1) deforested areas restrict gene flow; (2) larger species have lower genetic structure; (3) species with greater resource specialization have higher genetic structure; and (4) sites surrounded by more intact habitat have higher genetic diversity. Contrasting with previous work on bees, we found no associations between body size and genetic structure. Genetic structure was higher for species with greater resource specialization, and the amount of intact habitat between or surrounding sites was positively associated with parameters reflecting gene flow and genetic diversity. These results challenge the dominant paradigm that individuals of larger species disperse farther, and they suggest that landscape and resource requirements are important factors mediating dispersal.

Plant Resource Use and Pattern of Usage by the Naturalized Orchid Bee (Euglossa dilemma: Hymenoptera: Apidae) in Florida.

The Neotropical orchid bee Euglossa dilemma was found to be naturalized in southern Florida in 2003, and, by 2022, it had colonized the southern half of Florida. Observations of the bee's collection of plant resources, primarily flowers, were made from 2003 through to 2022 to document its plant usage and understand the patterns of its plant usage. The bee utilized 259 plant taxa, 237 species, and 22 horticultural forms, in 156 genera and 56 families in 263 total uses. Of 247 taxa of flowers, 120 were visited primarily for nectar, 46 for both nectar and pollen, 60 for pollen, including 42 buzz-pollinated flowers, 15 for fragrance chemicals for the males, and 5 for resin rewards by females for nesting. Fragrance chemicals were also collected by males from the leaves of 12 plant species. These extensive resource use data allowed the following predictions to be made. (1) The bee's presence in Florida, distant from its native region of Mexico and Central America and the geographical ranges of other orchid bees, would result the usage of many new taxa of plants. True, half, 74/148 (50%), of the genera and one third, 16/51(31%), of the plant families of the plants with flowers used by the bee were not previously recorded as being utilized by Euglossine bees. (2) Like other naturalized bees, it would use relatively more plants from its native range or congeners of these plants. True, 113/148 (76%) of genera with species bearing collected floral rewards are native or congeners with species native to the bee's native range. (3) Given the bee's long tongue, ability to buzz pollen from poricidal anthers, and ability to collect and use specialized rewards, it would disproportionately use plants with protected or highly specialized floral rewards. True, 180/247 (72%) utilized species bear rewards which were protected and unavailable to, or of no interest to, most other flower visitors.

Non-species-specific pollen transfer and double-reward production in euglossine-pollinated Vanilla.

Commonly attributed to orchids, the pollen movement in Vanilla has been associated with food deception and specific plant-pollinator relationships. This study investigated the role of flower rewards and pollinator specificity in the pollen transfer of a widely distributed member to the euglossinophilous Vanilla clade, V. pompona Schiede using data collected from Brazilian populations. These included investigations on morphology, light microscopy and histochemistry, and analysis of flowers scent using GC-MS. The pollinators and the mechanisms of pollination were recorded through focal observations. The yellow flowers of V. pompona are fragrant and offer nectar as reward. The major volatile compound of the V. pompona scent, carvone oxide, shows convergent evolution in Eulaema-pollinated Angiosperms. The pollination system of V. pompona is not species-specific, but its flowers are strongly adapted to pollination by large Eulaema males. Pollination mechanism is based in a combination of perfume collection and nectar seeking. The dogma of a species-specific pollination system based on food deception in Vanilla has been broken with the increase in studies on this Pantropical orchid genus. Here, least three bee species and dual reward-offering are involved in pollen transfer in V. pompona. Visitation frequency of bees collecting perfumes, used in courtship by male euglossines, is higher than in searching for food, as short-lived young euglossine males seem to be more interested in sex than food. A pollination system based on offering both nectar and perfumes as resources is described for the first time in orchids.

The Orchid Bee Fauna (Hymenoptera: Apidae: Euglossini) of a Neotropical Savanna: an Efficient Protocol to Assess Bee Community and Diversity Along Elevational and Habitat Complexity Gradients.

Males of euglossine bees, also known as orchid bees, are attracted to aromatic compounds and this feature has been exploited to collect them. Here we sampled orchid bee males using a rapid passive method in a Neotropical savanna ecosystem in Rio Preto State Park (PERP), southeastern Brazil. The sampling protocol consisted of 5-day surveys using scent traps at the beginning and end of the rainy seasons. PERP is inserted in a Brazilian savanna characterized by a mosaic of vegetation types, and elevational gradients. We also analyzed whether the habitat complexity and elevational gradients influence the richness and abundance of these bees. We collected a total of 996 individuals belonging to 14 species and four genera (Eufriesea Cockerell 1908, Euglossa Latreille 1802, Eulaema Lepeletier 1841, and Exaerete Hoffmannsegg 1817). Comparing our results with previous sampling protocols at PERP, higher abundance and richness were observed using traps than insect nets to survey these bees. In addition, the orchid bee fauna in PERP was successfully assessed by our rapid passive protocol, showing that this protocol seems to be useful for collecting orchid bees in open vegetation environments. We observed that the abundance of bees was lower at higher elevations, and both abundance and richness increased in more complex habitat. This may be due to the characteristics of Brazilian savannas where the lower elevations have higher habitat complexity, with more places for nest construction and resources for feeding and nesting.

Pollination of the strongly scented Sarcoglottis acaulis (Orchidaceae) by male orchid bees: nectar as resource instead of perfume.

The Neotropical orchid genus Sarcoglottis comprises ~40 species, which emit strong floral scents, presumably involved in pollinator attraction. Information on basic aspects of its natural history is scant, with the few studies available so far pointing to nectar-seeking orchid bees as pollinators. Here, we investigated the reproductive biology of Sarcoglottis acaulis, addressing the ecological meaning of its floral scent. In Atlantic Forest fragments of NE Brazil, we described the floral biology, determined the breeding system and recorded the pollinators of S. acaulis. Additionally, we chemically characterized its floral scent and assessed its role on pollinator attraction. Although self-compatible, S. acaulis depends on pollinators to boost fruit set. Male orchid bees of Eulaema atleticana and E. niveofasciata were the only recorded pollinators. They foraged for nectar only, in spite of the strong scent emitted by S. acaulis flowers. The floral scent is composed of six compounds, of which geraniol and nerol elicited electroantennographic responses in Eulaema bees. A synthetic mixture of these compounds attracted Eulaema bees in field assays but did not trigger the stereotyped scent-gathering behaviour. The floral scent of S. acaulis acts in signalling and nectar is the sole reward for pollinators. Despite the low pollinator frequency, S. acaulis shows a high fruit set (77%), particularly when compared to other orchids. Attributes such as pollinia that release small pollen loads, allowing a single pollinia-carrying bee to pollinate several flowers, low amount of nectar, steady-state flowering and traplining behaviour of pollinators, might act together to assure this outstanding fruit set.

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.

Subtle Chemical Variations with Strong Ecological Significance: Stereoselective Responses of Male Orchid Bees to Stereoisomers of Carvone Epoxide.

Different enantiomers of chiral compounds within floral perfumes usually trigger distinct responses in insects; however, this has frequently been neglected in studies investigating semiochemicals in plant-pollinator interactions. Approximately 1000 neotropical plants produce floral perfumes as the only reward for pollinators, i.e. male euglossine bees. The chiral compound carvone epoxide is a key component of the scent bouquet of many perfume-rewarding plants that are pollinated by males of Eulaema. Here, we tested the biological activity of the four carvone epoxide stereoisomers to four Eulaema species occurring in the Atlantic Rainforest of NE-Brazil. We determined the stereochemistry of carvone epoxide in the floral scent of several Catasetum species, tested whether the antennae of bees respond differentially to these stereoisomers and investigated if there is a behavioural preference for any of the stereoisomers. We found that 1) Catasetum species emit only the (-)-trans-stereoisomer of carvone epoxide, 2) for E. atleticana and E. niveofasciata antennal responses to the (-)-trans-carvone epoxide were significantly stronger than those to (-)-cis-carvone epoxide, 3) the strength and pattern of antennal responses to all 4 stereoisomers (separately tested) did not differ among Eulaema species, and 4) there were significant differences in attractiveness of the four stereoisomers to the bees species with the (-)-trans-stereoisomer being particularly attractive. We assume (-)-trans-carvone epoxide to be the dominant isomer in perfume-rewarding plants pollinated by Eulaema. The universal occurrence of carvone epoxide in Catasetum species pollinated by Eulaema, suggests that this compound has evolved in perfume-rewarding as a specific attractant for Eulaema bees as pollinators.

Pollination ecology of the Neotropical gesneriad Gloxinia perennis: chemical composition and temporal fluctuation of floral perfume.

Although common among orchids, pollination by perfume-gathering male euglossine bees is quite rare in other Neotropical families. In Gesneriaceae, for example, it is reported in two genera only, Drymonia and Gloxinia. Flowers of G. perennis are known to emit perfume, thereby attracting male euglossine bees as pollinators. However, detailed reports on the pollination ecology, as well as on chemistry of floral perfume of individuals in natural populations, are still missing. In this study, we report on the pollination ecology of G. perennis, focusing on the ecological significance of its floral perfume. In natural populations in Peru, we documented the floral biology and breeding system of G. perennis, as well as its interaction with flower visitors. We also characterised the chemical composition of floral perfume, as well as its timing of emission. Gloxinia perennis is self-compatible and natural pollination success is high. Spontaneous self-pollination occurs as a 'just in case strategy' when pollinators are scarce. Perfume-collecting males of Eulaema cingulata and El. meriana were identified as pollinators. The perfume bouquet of G. perennis consists of 16 compounds. (E)-Carvone epoxide (41%) and limonene (23%) are the major constituents. Perfume emission is higher at 09:00 h, matching the activity peak of Eulaema pollinators. Flowers of G. perennis have evolved a mixed strategy to ensure pollination (i.e. self- and cross-pollination), but cross-pollination is favoured. The size and behaviour of Eulaema males enables only these bees to successfully cross-pollinate G. perennis. Furthermore, G. perennis floral perfume traits (i.e. chemistry and timing of emission) have evolved to optimise the attraction of these bees.

Orchid Bee (Apidae: Euglossini) Communities in Atlantic Forest Remnants and Restored Areas in Paraná State, Brazil.

In this study, we compare orchid bee communities surveyed in four forest remnants of the Atlantic Forest and four reforested areas characterized by seasonal semi-deciduous forest vegetation in different successional stages (mature and secondary vegetation), located in southern Brazil. The sizes of forest remnants and reforested areas varied from 32.1 to 583.9 ha and from 11.3 to 33.3 ha, respectively. All reforested areas were located near one forest remnant. During samplings, totaling nine per study area, euglossine males were attracted to eight scent baits and captured with bait trap and entomological nets. Each forest remnant and its respective reforested area were sampled simultaneously by two collectors. We collected 435 males belonging to nine species of orchid bees distributed in four genera. The number of individuals and species did not differ significantly between different areas, except for a reforested area (size 33.3 ha), which was located far from its respective forest remnant. Our findings also revealed an apparent association between an orchid bee species (Euglossa annectans Dressler 1982) and the most preserved area surveyed in our study, suggesting that this bee is a potential indicator of good habitat quality in recuperating or preserved areas. Our results suggest that reforested habitats located near forest remnants have a higher probability of having reinstated their euglossine communities.

Evolution and diversity of floral scent chemistry in the euglossine bee-pollinated orchid genus Gongora.

UNLABELLED: • BACKGROUND AND AIMS: Animal-pollinated angiosperms have evolved a variety of signalling mechanisms to attract pollinators. Floral scent is a key component of pollinator attraction, and its chemistry modulates both pollinator behaviour and the formation of plant-pollinator networks. The neotropical orchid genus Gongora exhibits specialized pollinator associations with male orchid bees (Euglossini). Male bees visit orchid flowers to collect volatile chemical compounds that they store in hind-leg pouches to use subsequently during courtship display. Hence, Gongora floral scent compounds simultaneously serve as signalling molecules and pollinator rewards. Furthermore, because floral scent acts as the predominant reproductive isolating barrier among lineages, it has been hypothesized that chemical traits are highly species specific. A comparative analysis of intra- and inter-specific variation of floral scent chemistry was conducted to investigate the evolutionary patterns across the genus. • METHODS: Gas chromatography-mass spectrometry (GC-MS) was used to analyse the floral scent of 78 individuals belonging to 28 different species of Gongora from two of the three major lineages sampled across the neotropical region. Multidimensional scaling and indicator value analyses were implemented to investigate the patterns of chemical diversity within and among taxonomic groups at various geographic scales. Additionally, pollinator observations were conducted on a sympatric community of Gongora orchids exhibiting distinct floral scent phenotypes. • KEY RESULTS: A total of 83 floral volatiles, mainly terpenes and aromatic compounds, were detected. Many of the identified compounds are common across diverse angiosperm families (e.g. cineole, eugenol, ß-ocimene, ß-pinene and terpinen-4-ol), while others are relatively rare outside euglossine bee-pollinated orchid lineages. Additionally, 29 volatiles were identified that are known to attract and elicit collection behaviour in male bees. Floral scent traits were less variable within species than between species, and the analysis revealed exceptional levels of cryptic diversity. Gongora species were divided into 15 fragrance groups based on shared compounds. Fragrance groups indicate that floral scent variation is not predicted by taxonomic rank or biogeographic region. • CONCLUSIONS: Gongora orchids emit a diverse array of scent molecules that are largely species specific, and closely related taxa exhibit qualitatively and quantitatively divergent chemical profiles. It is shown that within a community, Gongora scent chemotypes are correlated with near non-overlapping bee pollinator assemblies. The results lend support to the hypothesis that floral scent traits regulate the architecture of bee pollinator associations. Thus, Gongora provides unique opportunities to examine the interplay between floral traits and pollinator specialization in plant-pollinator mutualisms.

Changes in Orchid Bee Communities Across Forest-Agroecosystem Boundaries in Brazilian Atlantic Forest Landscapes.

Deforestation has dramatically reduced the extent of Atlantic Forest cover in Brazil. Orchid bees are key pollinators in neotropical forest, and many species are sensitive to anthropogenic interference. In this sense understanding the matrix permeability for these bees is important for maintaining genetic diversity and pollination services. Our main objective was to assess whether the composition, abundance, and diversity of orchid bees in matrices differed from those in Atlantic forest. To do this we sampled orchid bees at 4-mo intervals from 2007 to 2009 in remnants of Atlantic Forest, and in the surrounding pasture and eucalyptus matrices. The abundance, richness, and diversity of orchid bees diminished significantly from the forest fragment toward the matrix points in the eucalyptus and pasture. Some common or intermediate species in the forest areas, such as Eulaema cingulata (F.) and Euglossa fimbriata Moure, respectively, become rare species in the matrices. Our results show that the orchid bee community is affected by the matrices surrounding the forest fragments. They also suggest that connections between forest fragments need to be improved using friendly matrices that can provide more favorable conditions for bees and increase their dispersal between fragments.

Is the capture success of orchid bees (Hymenoptera, Apoidea) influenced by different baited trap designs? A case study from southern Brazil

Orchid bees are increasingly applied on Neotropical biomonitoring and bioindication studies due to the relative easiness of sampling and identification when compared to other bee groups. A considerable number of orchid bee community studies have been adopting baited traps as a sampling method, especially for replication purposes. However, the trap attributes are variable, and hitherto no evaluation of different designs was carried out. Here, five attributes of baited traps were tested: trap volume, number of entrance holes, presence of landing platform, kind of landing platform, and fixation content. We use Mann-Whitney tests to access differences in richness and abundance capture rates for each trap design. We found that volume, number of entrance holes, and fixation content do not influence orchid bees capture. However, the design without landing platforms had a significantly higher capture rate for richness when compared with sanded landing platforms. On the other hand, analyzing the kind of landing platform, we detected a significantly higher richness and abundance for the trap with landing platforms glued with sand. Despite the fact that the effects of different designs tested here were very punctual, we consider that results from samples taken with different baited trap designs are comparable. Some adjustments on trap design can be done according to the particularities of future studies.

Sampling a biodiversity hotspot: the orchid-bee fauna (Hymenoptera: Apidae) of Tarapoto, northeastern Peru, the richest and most diverse site of the Neotropics

The orchid-bee fauna of the region of Tarapoto, northeastern Peru, was surveyed using seventeen different scents as baits to attract orchid-bee males. Six hundred and fifty-nine males belonging to 41 species were actively collected with insect nets during 120 hours in late July and early August, 2012. Euglossa dressleriMoure, 1968, Euglossa laurensiBembé, 2008, and Euglossa maculilabrisMoure, 1968, three species belonging to the Euglossa cybelia species-group, are here reported for Peru for the first time. Previous sporadic and unpublished samplings in the area recorded eleven additional species. With 53 species, the region of Tarapoto can be considered the richest single site in the Neotropics for orchid bees. Diversity, estimated with the Shannon-Wiener diversity index (H = 3.02), was also the highest ever recorded for orchid bees.

A fauna de abelhas euglossinas da região de Tarapoto, nordeste do Peru, foi amostrada com o uso de dezessete diferentes iscas aromáticas para atrair machos dessas abelhas. Seiscentos e cinquenta e nove machos pertencentes a 41 espécies foram coletados com rede entomológica durante 120 horas de amostragem no final de julho e início de agosto de 2012. Euglossa dressleriMoure, 1968, Euglossa laurensiBembé, 2008, e Euglossa maculilabrisMoure, 1968, três espécies pertencentes ao grupo Euglossa cybelia, foram registradas para o Peru pela primeira vez. Amostragens esporádicas prévias na área, não publicadas, registraram a ocorrência de doze espécies adicionais, não amostradas no presente estudo. Com 53 espécies registradas, a região de Tarapoto torna-se a área mais rica conhecida em abelhas euglossinas em toda a região Neotropical. A diversidade, estimada pelo índice de diversidade de Shannon-Wiener (H = 3,02), é também a mais alta já registrada para esse grupo de abelhas.

Is the Centro de Endemismo Pernambuco a biodiversity hotspot for orchid bees?

The orchid-bee faunas (Hymenoptera: Apidae: Euglossina) of the three largest forest remnants in the Centro de Endemismo Pernambuco, northeastern Brazil, namely Estação Ecológica de Murici (ESEC Murici), RPPN Frei Caneca, and a forest preserve belonging to Usina Serra Grande, in the states of Alagoas and Pernambuco, were surveyed using seventeen different scents as baits to attract orchid-bee males. Eight sites were established in the three preserves, where samplings were carried out using two protocols: insect netting and bait trapping. We collected 3,479 orchid-bee males belonging to 29 species during 160 hours in early October, 2012. Seven species were collected in the Centro de Endemismo Pernambuco for the first time. Richness proved to be one of the highest of the entire Atlantic Forest domain, and diversity in some sites, especially at ESEC Murici, revealed to be one of the highest in the Neotropics. Eulaema felipei Nemésio, 2010, a species previously recorded only at ESEC Murici, was found in no other preserve in the region and its conservation status is discussed.

As faunas de abelhas-das-orquídeas (Hymenoptera: Apidae: Euglossina) dos três maiores remanescentes florestais do Centro de Endemismo Pernambuco, nordeste do Brazil, sendo elas a Estação Ecológica de Murici (ESEC Murici), a RPPN Frei Caneca e um remanescente florestal pertencente à Usina Serra Grande, foram amostradas com o uso de dezessete diferentes iscas aromáticas para atrair machos dessas abelhas. Oito sítios amostrais foram selecionados nas três áreas, onde amostragens foram realizadas sob duas metodologias: coleta ativa com rede entomológica e coleta com armadilhas. Foram coletados 3.479 machos de abelhas euglossinas durante 160 horas no início de outubro de 2012. Sete espécies foram registradas no Centro de Endemismo Pernambuco pela primeira vez. A riqueza da região se mostrou uma das mais altas de toda a Mata Atlântica, e a diversidade em alguns locais, especialmente na ESEC Murici, revelou-se uma das mais altas de toda a região Neotropical. Eulaema felipei Nemésio, 2010, uma espécie que só havia sido registrada na ESEC Murici, não foi encontrada em nenhuma outra área e seu estado de conservação é discutido.

The orchid-bee fauna (Hymenoptera: Apidae) of a forest remnant in the southern portion of the Brazilian Amazon

The orchid-bee fauna of the region of Porto Velho, in the state of Rondônia, Brazil, close to the southernmost limits of the Amazon Basin, was surveyed for the first time using five different scents as baits to attract orchid-bee males. Five hundred and twenty-one males belonging to five genera and 29 species were collected with bait traps during 26 non-consecutive days from November, 2011 to January, 2012. Eulaema nigrita Lepeletier, 1841 and Eulaema meriana (Olivier, 1789) were the most common species in the region and, together, represented almost 50% of all collected bees. Although the observed richness conforms to similar inventories in the region, the diversity (H= 2.43) found in the present study is one of the highest ever recorded for orchid bees in the Amazon Basin.

A fauna de abelhas euglossinas da região de Porto Velho, estado de Rondônia, Brasil, próxima ao limite setentrional da Bacia Amazônica, foi amostrada pela primeira vez com o uso de cinco diferentes compostos aromáticos para atrair machos dessas abelhas. Quinhentos e vinte e um machos pertencentes a cinco gêneros e 29 espécies foram coletados em armadilhas durante 26 dias não consecutivos entre novembro de 2011 e janeiro de 2012. Eulaema nigrita Lepeletier, 1841 e Eulaema meriana (Olivier, 1789) foram as espécies mais comuns na região e, juntas, representaram quase 50% do total de abelhas capturadas. Embora a riqueza observada no presente estudo seja semelhante a de outros inventários na Amazônia brasileira, a diversidade encontrada (H= 2,43) é uma das mais altas já verificadas para a região.

The orchid-bee fauna (Hymenoptera: Apidae) of a forest remnant in the southern portion of the Brazilian Amazon / A fauna de abelhas-das-orquídeas (Hymenoptera: Apidae) de um remanescente florestal no extremo sul da Amazônia brasileira

The orchid-bee fauna of the region of Porto Velho, in the state of Rondônia, Brazil, close to the southernmost limits of the Amazon Basin, was surveyed for the first time using five different scents as baits to attract orchid-bee males. Five hundred and twenty-one males belonging to five genera and 29 species were collected with bait traps during 26 non-consecutive days from November, 2011 to January, 2012. Eulaema nigrita Lepeletier, 1841 and Eulaema meriana (Olivier, 1789) were the most common species in the region and, together, represented almost 50% of all collected bees. Although the observed richness conforms to similar inventories in the region, the diversity (H′= 2.43) found in the present study is one of the highest ever recorded for orchid bees in the Amazon Basin.

A fauna de abelhas euglossinas da região de Porto Velho, estado de Rondônia, Brasil, próxima ao limite setentrional da Bacia Amazônica, foi amostrada pela primeira vez com o uso de cinco diferentes compostos aromáticos para atrair machos dessas abelhas. Quinhentos e vinte e um machos pertencentes a cinco gêneros e 29 espécies foram coletados em armadilhas durante 26 dias não consecutivos entre novembro de 2011 e janeiro de 2012. Eulaema nigrita Lepeletier, 1841 e Eulaema meriana (Olivier, 1789) foram as espécies mais comuns na região e, juntas, representaram quase 50% do total de abelhas capturadas. Embora a riqueza observada no presente estudo seja semelhante a de outros inventários na Amazônia brasileira, a diversidade encontrada (H′= 2,43) é uma das mais altas já verificadas para a região.

Is the “Centro de Endemismo Pernambuco” a biodiversity hotspot for orchid bees? / O Centro de Endemismo Pernambuco é um ‘hotspot’ de biodiversidade para abelhas-das-orquídeas?

The orchid-bee faunas (Hymenoptera: Apidae: Euglossina) of the three largest forest remnants in the “Centro de Endemismo Pernambuco”, northeastern Brazil, namely Estação Ecológica de Murici (ESEC Murici), RPPN Frei Caneca, and a forest preserve belonging to Usina Serra Grande, in the states of Alagoas and Pernambuco, were surveyed using seventeen different scents as baits to attract orchid-bee males. Eight sites were established in the three preserves, where samplings were carried out using two protocols: insect netting and bait trapping. We collected 3,479 orchid-bee males belonging to 29 species during 160 hours in early October, 2012. Seven species were collected in the “Centro de Endemismo Pernambuco” for the first time. Richness proved to be one of the highest of the entire Atlantic Forest domain, and diversity in some sites, especially at ESEC Murici, revealed to be one of the highest in the Neotropics. Eulaema felipei Nemésio, 2010, a species previously recorded only at ESEC Murici, was found in no other preserve in the region and its conservation status is discussed.

As faunas de abelhas-das-orquídeas (Hymenoptera: Apidae: Euglossina) dos três maiores remanescentes florestais do Centro de Endemismo Pernambuco, nordeste do Brazil, sendo elas a Estação Ecológica de Murici (ESEC Murici), a RPPN Frei Caneca e um remanescente florestal pertencente à Usina Serra Grande, foram amostradas com o uso de dezessete diferentes iscas aromáticas para atrair machos dessas abelhas. Oito sítios amostrais foram selecionados nas três áreas, onde amostragens foram realizadas sob duas metodologias: coleta ativa com rede entomológica e coleta com armadilhas. Foram coletados 3.479 machos de abelhas euglossinas durante 160 horas no início de outubro de 2012. Sete espécies foram registradas no Centro de Endemismo Pernambuco pela primeira vez. A riqueza da região se mostrou uma das mais altas de toda a Mata Atlântica, e a diversidade em alguns locais, especialmente na ESEC Murici, revelou-se uma das mais altas de toda a região Neotropical. Eulaema felipei Nemésio, 2010, uma espécie que só havia sido registrada na ESEC Murici, não foi encontrada em nenhuma outra área e seu estado de conservação é discutido.

Sampling a biodiversity hotspot: the orchid-bee fauna (Hymenoptera: Apidae) of Tarapoto, northeastern Peru, the richest and most diverse site of the Neotropics / Amostrando um ‘hotspot’ de biodiversidade: a fauna de abelhas-das-orquídeas (Hymenoptera: Apidae) de Tarapoto, nordeste do Peru, a área mais rica e diversa da região Neotropical

The orchid-bee fauna of the region of Tarapoto, northeastern Peru, was surveyed using seventeen different scents as baits to attract orchid-bee males. Six hundred and fifty-nine males belonging to 41 species were actively collected with insect nets during 120 hours in late July and early August, 2012. Euglossa dressleri Moure, 1968, Euglossa laurensi Bembé, 2008, and Euglossa maculilabris Moure, 1968, three species belonging to the Euglossa cybelia species-group, are here reported for Peru for the first time. Previous sporadic and unpublished samplings in the area recorded eleven additional species. With 53 species, the region of Tarapoto can be considered the richest single site in the Neotropics for orchid bees. Diversity, estimated with the Shannon-Wiener diversity index (H′ = 3.02), was also the highest ever recorded for orchid bees.

A fauna de abelhas euglossinas da região de Tarapoto, nordeste do Peru, foi amostrada com o uso de dezessete diferentes iscas aromáticas para atrair machos dessas abelhas. Seiscentos e cinquenta e nove machos pertencentes a 41 espécies foram coletados com rede entomológica durante 120 horas de amostragem no final de julho e início de agosto de 2012. Euglossa dressleri Moure, 1968, Euglossa laurensi Bembé, 2008, e Euglossa maculilabris Moure, 1968, três espécies pertencentes ao grupo Euglossa cybelia, foram registradas para o Peru pela primeira vez. Amostragens esporádicas prévias na área, não publicadas, registraram a ocorrência de doze espécies adicionais, não amostradas no presente estudo. Com 53 espécies registradas, a região de Tarapoto torna-se a área mais rica conhecida em abelhas euglossinas em toda a região Neotropical. A diversidade, estimada pelo índice de diversidade de Shannon-Wiener (H′ = 3,02), é também a mais alta já registrada para esse grupo de abelhas.

Climate, physiological tolerance and sex-biased dispersal shape genetic structure of Neotropical orchid bees.

Understanding the impact of past climatic events on the demographic history of extant species is critical for predicting species' responses to future climate change. Palaeoclimatic instability is a major mechanism of lineage diversification in taxa with low dispersal and small geographical ranges in tropical ecosystems. However, the impact of these climatic events remains questionable for the diversification of species with high levels of gene flow and large geographical distributions. In this study, we investigate the impact of Pleistocene climate change on three Neotropical orchid bee species (Eulaema bombiformis, E. meriana and E. cingulata) with transcontinental distributions and different physiological tolerances. We first generated ecological niche models to identify species-specific climatically stable areas during Pleistocene climatic oscillations. Using a combination of mitochondrial and nuclear markers, we inferred calibrated phylogenies and estimated historical demographic parameters to reconstruct the phylogeographical history of each species. Our results indicate species with narrower physiological tolerance experienced less suitable habitat during glaciations and currently exhibit strong population structure in the mitochondrial genome. However, nuclear markers with low and high mutation rates show lack of association with geography. These results combined with lower migration rate estimates from the mitochondrial than the nuclear genome suggest male-biased dispersal. We conclude that despite large effective population sizes and capacity for long-distance dispersal, climatic instability is an important mechanism of maternal lineage diversification in orchid bees. Thus, these Neotropical pollinators are susceptible to disruption of genetic connectivity in the event of large-scale climatic changes.