Molecular identification of species of the genus Euglossa Latreille (Hymenoptera: Apidae, Euglossini)

Euglossine bees interact with more than 60 plant families of the Neotropical region. The richness and abundance of these bees have been intensively studied in different ecosystems using the methodology of capturing males with chemical baits. Females are poorly known for most of the species and morphological characters for their taxonomic classification have not yet been described. The purpose of this study was to use allozymes and restriction patterns of the mitochondrial regions 16S and Cyt b to identify species of Euglossa Latreille. Bees were collected while visiting Thevetia peruviana (Apocynaceae) flowers in five cities of the state of S?o Paulo, Brazil. Three Euglossa species were identified among the 305 individuals collected. Euglossa cordata (L.) was the only species found in all cities, while E. securigera Dressler and E. townsendi Cockerell were restricted to two and one cities respectively. EST-3 was a diagnostic marker, whereas ICD, MDH, ME and PGM were informative for species identification when used in combination. Restriction by VspI of the amplified 16S fragment differentiated the three species and showed intraspecific polymorphism for E. cordata and E. securigera. The Cyt b region showed distinctive patterns for E. townsendi but it was not possible to differentiate the other two species. Our results describe potentially useful genetic markers for the identification of Euglossa spp. at the species and group level.     

Three new cryptic species of Euglossa from Brazil (Hymenoptera,Apidae)

Three new species of orchid bees are described and figured from the Amazon and Atlantic forests of Brazil. Euglossa clausi sp. n., Euglossa moratoi sp. n., and Euglossa pepei sp. n. are distinguished from their close congeners Euglossa crassipunctata Moure, Euglossa parvula Dressler, and Euglossa sapphirina Moure, previously placed in the subgenus Euglossa (Glossurella) Dressler, 1982, a demonstrably paraphyletic assemblage requiring serious reconsideration. Their affinities with related species are discussed and pertinent characters are figured.     

Euglossa obrima, a new species of orchid bee from Mesoamerica, with notes on the subgenus Dasystilbe Dressler (Hymenoptera, Apidae)

A new species of the orchid bee subgenus Dasystilbe Dressler (Euglossini: Euglossa Latreille) is described and figured from a series of males and females collected broadly in Mesoamerica. Euglossa (Dasystilbe) obrima, sp. n., is differentiated from the one known species of Dasystilbe, Euglossa (Dasystilbe) villosa Moure, which occurs only in Panamá and perhaps Costa Rica. The subgenus and its constituent species are diagnosed, and comments provided on Dasystilbe.     

Euglossa williamsi, a new species of orchid bee from the Amazon Basin of Ecuador and Peru, with notes on its taxonomic association and biogeography (Hymenoptera, Apidae)

Euglossa williamsisp. n. is here described from the lowland Amazonian region in Ecuador and Peru, and as part of a small species assemblage within Euglossa consisting of Euglossa dodsoni Moure and Euglossa obtusa Dressler. An identification key to the males of the group is provided plus detailed figures of the new species and representative illustrations for the others. A brief discussion of the taxonomic and biogeographical implications of the new species is provided. New records in Honduras and Nicaragua are provided for the related Euglossa dodsoni.     

Microsatellite loci for Euglossa annectans (Hymenoptera: Apidae) and their variability in other orchid bees

Orchid or euglossine bees are conspicuous Hymenoptera of the Neotropics, where they pollinate numerous plants, including orchids. Allozyme-based analyses have suggested that their populations suffer from inbreeding, as evidenced by so-called diploid male production. We have developed nine polymorphic microsatellite loci for the widespread Euglossa annectans, with observed heterozygosities ranging from 0.143 to 0.952 and between 2 and 9 alleles per species. These loci will be useful for analysis of relatedness, population genetic structure and diploid male production in this and related species.     

Nesting biology and social structure of <Emphasis Type="Italic">Euglossa (Euglossa) townsendi</Emphasis> Cockerell (Hymenoptera,Apidae, Euglossini)

Summary. The nesting behavior of the euglossine bee Euglossa townsendi was studied on the campus of the University of São Paulo-Ribeirão Preto, SP, Brazil, from January 1994 to December 1999, using artificial nesting substrate and observation boxes. Twenty-one nests were founded during the study period, with the highest frequencies of nesting occurring during the hot, wet season. Each nest was founded by a single female and, after the completion of the last cell, she spent most of her time in the nest. The males left the nest immediately after emergence and did not return. Some females left the nest within a few days of eclosing, while others stayed in their natal nests and began to reactivate them. Reactivations were performed by a single female, by one or more females in the presence of the mother, by more than one female in the absence of the mother, and by more than one female in the presence of females that participated in the prior reactivation. According to behavior, the females were classified as forager/egg-laying and egg-laying females. The oviposition by egg-laying females was always preceded by oophagy. All of the forager/egg-laying and egg-laying females that were dissected had been inseminated. The behavior displayed by egg-laying females is characteristic of brood parasitism and fits the parental parasitism hypothesis developed as an alternative pathway by which insect sociality could have arisen. The behaviors displayed by E. townsendi, together with those reported for Euglossa cordata, show that both species have bionomic traits that resemble the conditions suggested as precursors of the origin of eusociality.Received 12 June 2003; revised 6 April 2004; accepted 22 April 2004.     

Long-term male aggregations of Euglossa melanotricha Moure (Hymenoptera: Apidae) on fern fronds Serpocaulon triseriale (Pteridophyta: Polypodiaceae)

A communal dormitory of male orchid bees, Euglossa melanotricha Moure, was monitored over a one-year period, when they passed the night in the fronds of a Serpocaulon triseriale (Polypodiaceae) fern. The bees used the same fronds continuously, moving to neighboring fronds as senescence set in. As many as 49 males were observed together on any one night, clinging to the midribs on the abaxial surface of up to five fern blades with their mandibles. A number of males returned to the same site to pass the night continuously over a number of months, and were observed making physical contact with one another without provoking agonistic behavior. Males of E. melanotricha appeared to prefer sleeping at sites close to nests and potential sources of odoriferous essences, such as orchids (Orchidaceae).     

Floral sources used by the orchid bee Euglossa cordata (Linnaeus, 1758) (Apidae: Euglossini) in an urban area of south-eastern Brazil

Although orchid bees (Apidae: Euglossini) are known as key pollinators in tropical ecosystems, knowledge of their floral sources is still scarce, especially for those species commonly found in urban environments. We aimed to identify the pollen, nectar and resin sources used by the widespread species Euglossa cordata in an urban area in south-eastern Brazil. The residual pollen from 81 brood cells of nine nests reactivated between October 2013 and December 2014 was acetolysed and analysed. A total of 50 pollen types belonging to 20 botanical families were identified in the samples. Pollen sources included species from seven families; five of them were plants with poricidal anthers (Bixaceae, Commelinaceae, Fabaceae, Melastomataceae and Solanaceae). The mass-flowering trees Handroanthus chrysotrichus and H. heptaphyllus (Bignoniaceae) are firstly reported as important pollen sources to an orchid bee species. Nectar was collected primarily from plants with long, tubular corolla as Acanthaceae, Apocynaceae, Bignoniaceae and Convolvulaceae. The vine species Dalechampia stipulacea (Euphorbiaceae) acted as a floral resin source. All pollen sources consisted of native plants whereas some exotic plant species were visited for nectar collection. Although nesting in an area encompassed by a high proportion of invasive plant species, Euglossa cordata females preferred to visit native plants to gather floral resources.     

Revision of the orchid bee subgenus Euglossella (Hymenoptera, Apidae), Part I, The decorata species group

Euglossella, one of the most distinctive subgenera of orchid bees of the genus Euglossa, is composed of two characteristic assemblages of species, one of them comprising bees bearing the strongly metallic integument trademark of the genus (viridis species group), and the other consisting of bees with a brown integument shaded with metallic iridescence (decorata species group). Here we provide the first of two parts of a revision of Euglossella, providing diagnostic definitions for the subgenus, the decorata species group, and all the species included therein. Six species are included in the decorata group, one new: Euglossa (Euglossella) aurantia, sp. n.; Euglossa (Euglossella) apiformis Schrottky, resurrected status; Euglossa (Euglossella) decorata Smith, revised status; Euglossa (Euglossella) singularis Mocsáry, revised status; Euglossa (Euglossella) cosmodora Hinojosa-Díaz and Engel; and Euglossa (Euglossella) perpulchra Moure and Schlindwein. Euglossa meliponoides Ducke and Euglossa urarina Hinojosa-Díaz and Engel are newly synonymized under Euglossa decorata, Euglossa decorata ruficauda Cockerell is synonymized under Euglossa singularis, and a neotype is designated for Euglossa apiformis.     

Evaluation of the RAPD profiles from different body parts of Euglossa pleosticta Dressler male bees (Hymenoptera: Apidae, Euglossina)

In the current literature, information is scarce on which part of the adult insect body is suitable for isolation of genomic DNA for genetic analysis based on DNA-markers. In this study, we evaluated RAPD profiles generated from total genomic DNA isolated from distinct body parts (head, legs, thorax + wings and abdomen) of 12 males of Euglossa pleosticta Dressler. From the total of bands analyzed, 9.0% did not show reproducibility. Percent variations of bands in each body segment were: 1.1% (head); 0.4% (legs); 0.8% (thorax/wings) and 6.7% (abdomen). The much higher variation (chi2(one sample) = 10.27; df = 1; P < 0.01) in the RAPD profiles obtained by using DNA isolated from abdomen of the euglossine males suggests that this body part of adult insects should be avoided in DNA extraction procedures. Conversely, the low variation among the RAPD profiles obtained from amplifications of genomic DNA extracted from head, legs and thorax/wings indicates that all these body parts of male bees are equally useful and secure for using in isolation and amplification procedures of total genomic DNA.     

Solitary and group nesting in the orchid bee <Emphasis Type="Italic">Euglossa hyacinthina</Emphasis> (Hymenoptera,Apidae)

Summary Orchid bees (Euglossini) provide a potentially informative contrast for examining origins of advanced social behaviour in bees because they are the only tribe in the apine clade that do not form large colonies or have queens and workers. We investigated natural nests of Euglossa hyacinthina Dressler, an orchid bee that nests singly or in groups. By comparing the two types of nests, we examined if individuals in a group merely share the nest (are communal) or exhibit a level of social organization where there is reproductive division of labour among the females. Observations are consistent with communal nesting, indicating that all females in group nests are reproductively similar to the solitary nesting females because the provisioning of young, as well as the ovary development and mating status of females sharing nests were not different than that of solitary-nesting females. Also, multiple female nests did not produce a female-biased brood as predicted for nests with reproductive division of labour. We also investigated potential advantages of group nesting vs. individual nesting. We demonstrate that per capita offspring production is lower in nests with more than one female. However, we found that nests with single females were left unattended for longer periods of time during foraging, and that there was a high incidence of natural enemy attack in nests when females were absent. Group and solitary nesting may be advantageous under different conditions.Received 3 December 2002; revised 7 March 2003; accepted 2 April 2003.     

Mitochondrial DNA Diversity of Orchid Bee Euglossa fimbriata (Hymenoptera: Apidae) Populations Assessed by PCR-RFLP

Euglossa fimbriata is a euglossine species widely distributed in Brazil and occurring primarily in Atlantic Forest remnants. In this study, the genetic mitochondrial structure of E. fimbriata from six Atlantic Forest fragments was studied by RFLP analysis of three PCR-amplified mtDNA gene segments (16S, COI-COII, and cyt b). Ten composite haplotypes were identified, six of which were exclusive and represented singleton mitotypes. Low haplotype diversity (0.085–0.289) and nucleotide diversity (0.000–0.002) were detected within samples. AMOVA partitioned 91.13% of the overall genetic variation within samples and 8.87% (?_st = 0.089; P < 0.05) among samples. Pairwise comparisons indicated high levels of differentiation among some pairs of samples (?_st = 0.161–0.218; P < 0.05). These high levels indicate that these populations of E. fimbriata, despite their highly fragmented landscape, apparently have not suffered loss of genetic variation, suggesting that this particular population is not currently endangered.     

Characterization of the orchid bee Euglossa viridissima (Apidae: Euglossini) and a novel cryptic sibling species,by morphological,chemical, and genetic characters

In orchid bees, males signal their availability as mates by fanning ‘perfumes’, i.e. blends of volatiles that are collected from environmental sources and stored in hind leg pouches. The chemical composition of such perfumes in males with either two or three mandibular teeth has previously led to the discovery of two sympatric, cryptic lineages within Euglossa viridissima Friese on the Yucatan peninsula, Mexico. Here, we combine chemical, morphological, and genetic data for an integrated characterization of the two lineages. The lectotype of E. viridissima Friese in the Museum of Natural History in Vienna has two mandibular teeth, and the species name viridissima must thus be assigned to the predominantly bidentate lineage, whereas the completely tridentate lineage is described as a novel species, Euglossa dilemma sp. nov. Bembé & Eltz. Chemical profiling and microsatellite genotyping revealed that E. viridissima males can occasionally (～10% of individuals) express a third mandibular tooth, but this tooth is not positioned centrally on the mandible as in E. dilemma, but is displaced towards the tip. Thus, males of the two lineages can be unambiguously diagnosed by mandibular characters alone. Based on 889 bp of CO1 sequence data, we confirm that E. viridissima and E. dilemma constitute a monophyletic group within the genus Euglossa. However, CO1 alone failed to separate these two lineages due to the lack of parsimony‐informative sites. Both species occur in broad sympatry across Central America, but the orchid bees recently introduced to Florida have three mandibular teeth in males, i.e. belong to E. dilemma. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1064–1076.     

Searching for Euglossa cyanochlora Moure, 1996 (Hymenoptera: Apidae), one of the rarest bees in the world

Euglossa cyanochlora Moure, 1996 (Hymenoptera: Apidae: Euglossina) is known from only two specimens and is considered as one of the rarest bees. An intensive search for this species in its expected area of occurrence in eastern Brazil was carried out during three consecutive summers and involved over 1,000?h of active sampling in 50 sites distributed among 20 forest remnants. Almost 15,000 orchid bee males were attracted to scent baits and collected, but only 24 of them belonged to E. cyanochlora. Some degree of mitochondrial gene (COI, cytB, and 16S) variation was observed in this species. Although no intra-specific variation was identified at the 16S locus, three and six haplotypes were characterized at the COI and cytB genes, respectively. Combined data from field work and molecular analysis suggest that the species southernmost distribution limit is close to its type locality, near Parque Nacional do Monte Pascoal, in southern Bahia. The conservation status of E. cyanochlora is discussed and measures for its protection are here proposed.     

Potential distribution of orchid bees outside their native range: The cases of Eulaema polychroma (Mocsáry) and Euglossa viridissima Friese in the USA (Hymenoptera: Apidae)

Aim This study aimed to evaluate the probability of suitable habitats in the USA for two adventive orchid bee species (Eulaema polychroma (Mocsáry) and Euglossa viridissima Friese), one of which has become established in southern Florida despite the absence of its associated orchid hosts. Location North and Central America, northern South America and the Caribbean. Methods Using positive occurrence data within the native range of both orchid bee species, Maxent species distribution modelling was employed to evaluate the probability of suitable habitats in the USA. The power of predictability for the model was tested using partitions of the data. Results Our results show the absence of suitable habitat in southern Arizona for E. polychroma to maintain populations there, as well as establishing the northernmost limit for the species at around 29°N in north‐western Mexico. Suitable habitat was found for E. viridissima in various locations throughout southern Florida. This species is predicted to spread to occupy roughly the southern half of the Florida Peninsula. Main conclusions The findings indicate that species distribution modelling is useful for evaluating records of species occurrence outside of their native range. Our results indicate that the isolated record of a male of E. polychroma from southern Arizona should not be considered representative of an established population in the absence of further males and females from the same region. Conversely, E. viridissima has successfully become established in south‐eastern Florida after a seemingly accidental introduction first noticed in the summer of 2003. We discuss the naturalization of E. viridissima in Florida, the probability of suitable habitat across the Caribbean (where orchid bees are otherwise natively absent today) and the absence of perfume orchids (Orchidaceae). Lastly, we discuss the implications of these results for understanding the biology and biogeography of Euglossini.     

Seasonal nest characteristics of a facultatively social orchid bee,Euglossa viridissima,in the Yucatan Peninsula,Mexico

Euglossines have long been regarded as largely solitary, though some species are known to exhibit social behavior. We studied the nesting behavior of Euglossa viridissima over an annual cycle, comparing sociality and offspring production across the rainy (RS) and dry seasons (DS) in the Yucatan Peninsula of Mexico. Nests were built in both the RS and the DS, but with greater nest initiation and brood provisioning in the RS, presumably as a consequence of more floral resources at this time of year. Across the year, numerical sex ratios were female biased (0.7 as females/total); sex ratios varied across individual nests from 0.3 to 1.00, though without a clear relationship to sociality. Egg-to-adult development was quicker in females than males and, within a sex, quicker when ambient temperatures were higher. Multi-female (social) nests were only founded at the end of the RS and the beginning of the DS, coincided with the presence of Hymenopteran and Dipteran parasites in nests headed by solitary females. Reduced floral resources and a higher risk of parasitism, possibly coupled with higher female density or reduced nesting sites, may be factors favoring the formation of multi-female associations in this euglossine. Better nourishment of foundress females in the RS may improve lifespan and permit overlapping generations which, coupled with the kin structure of their nests, may favor social nesting in E. viridissima.     

Suction feeding in orchid bees (Apidae: Euglossini)

Energy flux during nectar feeding is maximized at an intermediate sugar concentration, the value of which depends on the morphology of the feeding apparatus and the modality of fluid feeding. Biomechanical models predict that a shift from capillary-based lapping to suction feeding will lead to a decrease in this optimal sugar concentration. Here, I demonstrate that the four major genera of orchid bees (Apidae: Euglossini) are suction feeders and provide experimental evidence that the feeding optimum for one species, Euglossa imperialis, falls below the optimum for bee taxa that lap.     

Microsatellite loci for euglossine bees (Hymenoptera: Apidae)

The Neotropical Euglossini (Hymenoptera: Apidae) are important pollinators of many flowering plants, particularly orchids. Lack of highly polymorphic genetic markers for euglossine species has limited the study of their social organization and inbreeding. We therefore developed microsatellite markers for two species, Eulaema nigrita (11 loci) and Euglossa cordata (nine loci), most of which were highly polymorphic in the source species and in a range of related euglossine bees.     

Silver staining of nucleolar organizer regions (NOR) in some species of Hymenoptera (bees and parasitic wasp) and Coleoptera (lady-beetle)

Adaptations of the nucleolar organizer regions (NOR) banding technique using precipitation of silver salts significantly improved the NOR characterization of some species of hymenopterans and one coleopteran. The bee Melipona marginata (2n = 18) showed one metacentric pair of chromosomes with a NOR in the pericentromeric position. The parasitic wasp Mellitobia australica (2n = 12) also showed one metacentric pair with a strongly Ag-positive NOR. The male lady-beetle Cycloneda sanguinea (2n = 18 + Xy(p)) displayed a NOR on a pair of acrocentric autosomes. In the male Euglossa sp. (a haplodiploid species) (n = 21) the NOR were multiple, and occurred in five chromosomes. In the bee Plebeia sp. 1 (2n = 34) the NOR seemed restricted to one of the homologues of a metacentric pair. The systematic advances brought out by using this technique in the context of current theories of karyotypic evolution of these taxa are described and discussed.