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.     

Microsatellite loci for the stingless bee Melipona rufiventris (Hymenoptera: Apidae)

Eight microsatellite primers were developed from ISSR (intersimple sequence repeats) markers for the stingless bee Melipona rufiventris. These primers were tested in 20 M. rufiventris workers, representing a single population from Minas Gerais state. The number of alleles per locus ranged from 2 to 5 (mean = 2.63) and the observed and expected heterozygosity values ranged from 0.00 to 0.44 (mean = 0.20) and from 0.05 to 0.68 (mean = 0.31), respectively. Several loci were also polymorphic in M. quadrifasciata, M. bicolor, M. mandacaia and Partamona helleri and should prove useful in population studies of other stingless bees.     

Ultrastructural characterization of spermatozoa in euglossine bees (Hymenoptera, Apidae, Apinae)

Summary. Euglossine spermatozoa are the longest described to date for the Hymenoptera. This cell includes a head and a flagellar region. In transverse sections, the acrosome is circular at the tip but has an oval contour along most of its length. The perforatorium penetrates into a deep cavity in the nuclear tip. The flagellum consists in an axoneme, a pair of mitochondrial derivatives, a centriolar adjunct and a pair of accessory bodies. The axoneme has a 9+9+2 microtubule pattern which becomes gradually disorganized in the final portion, with the central microtubules and the nine doublets terminating simultaneously, followed by the accessory microtubules. The mitochondrial derivatives are asymmetric both in length and diameter. Sectioned transversally, the derivatives are ellipsoidal or have a pear shape. The larger one has a more obvious paracrystalline region. The centriolar adjunct begins at the nuclear base and extends parallel to the axoneme until it encounters the smaller mitochondrial derivative, on which it fits, making a concave groove. In addition to these consistent euglossine features, species-specific differences that might be useful in phylogenetic work on the group are also noted.Received 18 October 2003; revised 4 September 2004; accepted 4 October 2004.     

Microsatellite loci for the eusocial Lasioglossum malachurum and other sweat bees (Hymenoptera,Halictidae)

Sweat bees (family Halictidae) comprise a numerous and diverse group that are arguably among the most socially labile of all insect taxa. Given the lack of highly variable markers for eusocial species of the family, we developed a suite of dinucleotide and trinucleotide markers for one of its members, the Eurasian Lasioglossum malachurum, and used them to amplify DNA from other halictids. Loci were highly variable in L. malachurum and amplified DNA from many other halictids.     

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.     

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.     

Genetic divergence between Melipona quadrifasciata Lepeletier (Hymenoptera,Apidae) populations

Melipona quadrifasciata is a stingless bee widely found throughout the Brazilian territory, with two recognized subspecies, M. quadrifasciata anthidioides, that exhibits interrupted metasomal stripes, and M. quadrifasciata quadrifasciata, with continuous metasomal stripes. This study aimed to estimate the genetic variability of these subspecies. For this purpose, 127 colonies from 15 Brazilian localities were analyzed, using nine species-specific microsatellite primers. At these loci, the number of alleles ranged from three to 15 (mean: 7.2), and the observed heterozygosity (H_o) ranged from 0.03–0.21, while the expected heterozygosity (H_e) ranged from 0.23–0.47. The genetic distances among populations ranged from 0.03–0.45. The F_ST multilocus value (0.23) indicated that the populations sampled were structured, and the clustering analysis showed the formation of two subgroups and two more distant populations. The first group contained the subspecies M. quadrifasciata quadrifasciata, and the other, the subspecies M. quadrifasciata anthidioides and the two M. quadrifasciata populations with continuous metasomal stripes from northern Minas Gerais. These results confirmed that the yellow metasomal stripes alone are not a good means for correctly identifying the different subspecies of M. quadrifasciata.     

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.     

Phylogeny,diversification patterns and historical biogeography of euglossine orchid bees (Hymenoptera: Apidae)

The orchid bees constitute a clade of prominent insect pollinators distributed throughout the Neotropical region. Males of all species collect fragrances from natural sources, including flowers, decaying vegetation and fungi, and store them in specialized leg pockets to later expose during courtship display. In addition, orchid bees provide pollination services to a diverse array of Neotropical angiosperms when foraging for food and nesting materials. However, despite their ecological importance, little is known about the evolutionary history of orchid bees. Here, we present a comprehensive molecular phylogenetic analysis based on ～4.0 kb of DNA from four loci [cytochrome oxidase (CO1), elongation factor 1‐α (EF1‐α), arginine kinase (ArgK) and RNA polymerase II (Pol‐II)] across the entire tribe Euglossini, including all five genera, eight subgenera and 126 of the approximately 200 known species. We investigated lineage diversification using fossil‐calibrated molecular clocks and the evolution of morphological traits using disparity‐through‐time plots. In addition, we inferred past biogeographical events by implementing model‐based likelihood methods. Our dataset supports a new view on generic relationships and indicates that the cleptoparasitic genus Exaerete is sister to the remaining orchid bee genera. Our divergence time estimates indicate that extant orchid bee lineages shared a most recent common ancestor at 27–42 Mya. In addition, our analysis of morphology shows that tongue length and body size experienced rapid disparity bursts that coincide with the origin of diverse genera (Euglossa and Eufriesea). Finally, our analysis of historical biogeography indicates that early diversification episodes shared a history on both sides of Mesoamerica, where orchid bees dispersed across the Caribbean, and through a Panamanian connection, thus reinforcing the hypothesis that recent geological events (e.g. the formation of the isthmus of Panama) contributed to the diversification of the rich Neotropical biota. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 552–572.     

Morphological and functional aspects of volatile-producing glands in bees (Hymenoptera: Apidae)

Abstract In this paper we focus on the occurrence and morphological aspects of exocrine glands in several bee species. Morphology of head labial, mandibular, Dufour, and abdominal tegumentar glands was investigated under light microscopy, scanning electron microscopy and transmission electron microscopy. Most of such glands present cells with cytoplasm homogeneous and acidophilic, or contain small apparently empty vacuoles. The cytoplasm cells' ultrastructure showed a well developed smooth endoplasmic reticulum, many polymorphic mitochondria, rare Golgi, lipid droplets, myelin figures, and many basal and apical plasma membrane infoldings. All these results are discussed in the text.     

The behavioural and structural aspects of grooming and related activities in euglossine bees (Hymenoptera: Apidae)

The movements and structures involved in grooming, resin and pollen manipulation, and collection of aromatic material are described for members of the tribe Euglossini. These bees typically groom with each leg while hanging by their mandibles, working from the head backwards. Collection and transfer of aromatic material is described after re-evaluation using fluorescent powder. Resin collection involves asynchronous ipsilateral transfer of the resin to the hindtibia. Pollen collection, in contrast, involves synchronous ipsilateral transfer. Areas of the body that are not groomed are illustrated, and the various plants and animals that exploit these regions discussed. The similarities between the behaviours of euglossines and bumblebees supports the idea that they are closely related.     

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.     

蜜蜂花粉采集器官和采集飞行的线性比例分析

本研究从采粉工蜂飞行中能量消耗相关的几个方面入手,分析了蜜蜂属(Apis) 8个物种的花粉采集器官。结果表明,花粉筐表面积、翅膀表面积、体重及胸部动力容量与蜂种个体的体长呈极显著相关,并且它们随蜂种个体的增大而呈对数线性比例增加。除意大利蜜蜂(A·mellifera ligustica)以外,花粉团重量与花粉筐和基跗节表面积成线性比例。工蜂负重前后重量的变化与花粉筐和翅膀的表面积不成比例[动物学报51 (5) :947 -951 , 2005]。     

Detection of aerosolized bacterial spores (Bacillus atrophaeus) using free-flying honey bees (Hymenoptera: Apidae) as collectors

An aerosol cloud of Bacillus atrophaeus (previously B. subtilis variety niger) spores, an anthrax surrogate, was created in a large 0.4 ha (1 ac), bee-containing, open-mesh tent. Bees from a B. atrophaeus uncontaminated hive flying through the cloud adsorbed the spores in statistically significant quantities. After removal of the B. atrophaeus contaminated hive and introduction of another B. atrophaeus uncontaminated hive, the bees again were monitored for the next few days for B. atrophaeus spores. B. atrophaeus spores accumulated on the bees bodies following their exposure to the residual B. atrophaeus contamination in the tent. The spore loads on the bees quickly returned to background levels after the hives were removed from the contaminated tent area. It may therefore be practical to use honey bee colonies to monitor foraging areas for disease-causing spores.     

Genetic variability in five populations of Partamona helleri (Hymenoptera, Apidae) from Minas Gerais State, Brazil

Partamona is a Neotropical genus of stingless bees that comprises 33 species distributed from Mexico to southern Brazil. These bees are well-adapted to anthropic environments and build their nests in several substrates. In this study, 66 colonies of Partamona helleri from five localities in the Brazilian state of Minas Gerais (São Miguel do Anta, Teixeiras, Porto Firme, Viçosa and Rio Vermelho) were analyzed using nine microsatellite loci in order to assess their genetic variability. Low levels of observed (H_o = 0.099-0.137) and expected (H _e = 0.128-0.145) heterozygosity were encountered and revealed discrete genetic differentiation among the populations (F _ST = 0.025). AMOVA further showed that most of the total genetic variation (94.24%) in P. helleri was explained by the variability within local populations.     

Host-seeking behaviour of tracheal mites (Acari: Tarsonemidae) on honey bees (Hymenoptera: Apidae)

The behaviour of the endoparasitic tracheal mite, Acarapis woodi (Rennie) on honey bees (Apis mellifera L.) is a challenge to observe because of its small size. Through a microscope, we videotaped this mite's movement on young bees, dead bees and bees exposed to vegetable oil. Previous studies have shown that solid vegetable oil decreases mite infestations in a bee colony. We hypothesized that the oil alters mite behaviour to the detriment of the parasite, thus helping to safeguard the host. Habitat-seeking behaviour, identified as necessary for mites to locate a new host environment, was disrupted on both dead and oil-treated bees. Questing behaviour, which is associated with transfer between hosts, increased significantly on the dead and oily bees. The behaviours of mites were significantly different between all three treatments (x ²=494.96, p<0.001 on dead bees and x ²=851.11, p<0.001 on oily bees). Both questing and seeking behaviours were significantly different on each of the thoracic treatments (F _2,66=7.88, p<0.001 and F _2,66=21.28, p<0.001) and mite questing behaviour was not altered between males and females on live or oily bees (F _1,22=0.25, p<0.62), but habitat seeking was (F _1,22=7.42, p<0.012). The male questing and habitat-seeking behaviours were observed. We conclude that oil-treated bees gained protection from habitat-seeking mites because the normal behaviour of the mites seeking an oviposition site is interrupted.