Phylogenetic position of the bee genera Ancyla and Tarsalia (Hymenoptera: Apidae): a remarkable base compositional bias and an early Paleogene geodispersal from North America to the Old World

(R)-(+)-γ-Decalactone is Conserved in North America as a Pheromone Component of Osmoderma eremicola (Coleoptera: Scarabaeidae) and a Kairomone of Elater abruptus (Coleoptera: Elateridae)

The scarab genus Osmoderma (Coleoptera: Scarabaeidae) includes several large species called hermit beetles that develop within dead and decaying hardwood trees. Males of at least three Palearctic species produce the aggregation-sex pheromone (R)-(+)-γ-decalactone, including the endangered O. eremita (Scopoli). However, hermit beetles have received less attention in the western hemisphere, resulting in a large gap in our knowledge of the chemical ecology of Nearctic species. Here, we identify (R)-( +)-γ-decalactone as the primary component of the aggregation-sex pheromone of the North American species Osmoderma eremicola (Knoch). Field trials at sites in Wisconsin and Illinois revealed that both sexes were attracted to lures containing (R)-(+)-γ-decalactone or the racemate, but only males of O. eremicola produced the pheromone in laboratory bioassays, alongside an occasional trace of the chain-length analog γ-dodecalactone. Females of the congener O. scabra (Palisot de Beauvois) were also significantly attracted by γ-decalactone, suggesting further conservation of the pheromone, as were females of the click beetle Elater abruptus Say (Coleoptera: Elateridae), suggesting that this compound may have widespread kairomonal activity. Further research is needed to explore the behavioral roles of both lactones in mediating behavioral and ecological interactions among these beetle species.

Phylogenomics and topological conflicts in the tribe Anthospermeae (Rubiaceae)

Genome skimming (shallow whole-genome sequencing) offers time- and cost-efficient production of large amounts of DNA data that can be used to address unsolved evolutionary questions. Here we address phylogenetic relationships and topological incongruence in the tribe Anthospermeae (Rubiaceae), using phylogenomic data from the mitochondrion, the nuclear ribosomal cistron, and the plastome. All three genomic compartments resolve relationships in the Anthospermeae; the tribe is monophyletic and consists of three major subclades. Carpacoce Sond. is sister to the remaining clade, which comprises an African subclade and a Pacific subclade. Most results, from all three genomic compartments, are statistically well supported; however, not fully consistent. Intergenomic topological incongruence is most notable in the Pacific subclade but present also in the African subclade. Hybridization and introgression followed by organelle capture may explain these conflicts but other processes, such as incomplete lineage sorting (ILS), can yield similar patterns and cannot be ruled out based on the results. Whereas the null hypothesis of congruence among all sequenced loci in the individual genomes could not be rejected for nuclear and mitochondrial data, it was rejected for plastid data. Phylogenetic analyses of three subsets of plastid loci identified using the hierarchical likelihood ratio test demonstrated statistically supported intragenomic topological incongruence. Given that plastid genes are thought to be fully linked, this result is surprising and may suggest modeling or sampling error. However, biological processes such as biparental inheritance and inter-plastome recombination have been reported and may be responsible for the observed intragenomic incongruence. Mitochondrial insertions into the plastome are rarely documented in angiosperms. Our results indicate that a mitochondrial insertion event in the plastid trnS GGA - rps4 IGS region occurred in the common ancestor of the Pacific clade of Anthospermeae. Exclusion/inclusion of this locus in phylogenetic analyses had a strong impact on topological results in the Pacific clade.

The evolutionary history of bees in time and space

Bees are the most significant pollinators of flowering plants. This partnership began ca. 120 million years ago, but the uncertainty of how and when bees spread across the planet has greatly obscured investigations of this key mutualism. We present a novel analysis of bee biogeography using extensive new genomic and fossil data to demonstrate that bees originated in Western Gondwana (Africa and South America). Bees likely originated in the Early Cretaceous, shortly before the breakup of Western Gondwana, and the early evolution of any major bee lineage is associated with either the South American or African land masses. Subsequently, bees colonized northern continents via a complex history of vicariance and dispersal. The notable early absences from large landmasses, particularly in Australia and India, have important implications for understanding the assembly of local floras and diverse modes of pollination. How bees spread around the world from their hypothesized Southern Hemisphere origin parallels the histories of numerous flowering plant clades, providing an essential step to studying the evolution of angiosperm pollination syndromes in space and time.

Evolution of andrenine bees reveals a long and complex history of faunal interchanges through the Americas during the Mesozoic and Cenozoic

Bees are presumed to have arisen in the early to mid-Cretaceous coincident with the fragmentation of the southern continents and concurrently with the early diversification of the flowering plants. Here, we apply DNA sequences from multiple genes to recover a dated phylogeny and historical biogeographic of andrenine bees, a large group of 3000 species mainly distributed in arid areas of North America, South America, and the Palearctic region. Our results corroborate the monophyly of Andreninae and points toward a South America origin for the group during the Late Cretaceous. Overall, we provide strong evidence of amphitropical distributional pattern currently observed in the American continent as result of faunal interchange in at least three historical periods, much prior to the Panama Isthmus closure. The Palearctic diversity is shown to have arisen from North America during the Eocene and Miocene, and the Afrotropical lineages likely originated from the Palearctic region in the Miocene when the Sahara Desert was mostly vegetated. The incursions from South to North America and then onto the Old World are chronological congruent with periods when open-vegetation habitats were available for trans-continental dispersal and at the times when aridification and temperature decline offered favorable circumstances for bee diversification.

Phylogenomics and historical biogeography of the cleptoparasitic bee genus Nomada (Hymenoptera: Apidae) using ultraconserved elements

The genus Nomada Scopoli (Hymenoptera: Apidae) is the largest genus of brood parasitic bees with nearly 800 species found across the globe and in nearly all biogeographic realms except Antarctica. There is no previous molecular phylogeny focused on Nomada despite their high species abundance nor is there an existing comprehensive biogeography for the genus. Using ultraconserved element (UCE) phylogenomic data, we constructed the first molecular phylogeny for the genus Nomada and tested the monophyly of 16 morphologically established species groups. We also estimated divergence dates using fossil calibration points and inferred the origin and of this genus around the globe. Our phylogeny recovered 14 of the 16 previously established species groups as monophyletic. The superba and ruficornis groups, however, were recovered as non-monophyletic and need to be re-evaluated using morphology. Divergence dating and historic biogeographic analyses performed on the phylogenetic reconstruction indicates that Nomada most likely originated in the Holarctic ∼65 Mya. Geodispersal into the southern hemisphere occurred three times; once during the Eocene into the Afrotropics, once during the Oligocene into the Neotropics, and once during the Miocene into Australasia. Geodispersal across the Holarctic was most frequent and occurred repeatedly throughout the Cenozoic era, using the De Geer, Thulean, and the Bering Land Bridges. This is the first instance of a bee using both the Thulean and De Geer land bridges and has implications of how early bee species dispersed throughout the Palearctic in the late Cretaceous and early Paleogene.

A Likelihood-Ratio Test for Lumpability of Phylogenetic Data: Is the Markovian Property of an Evolutionary Process retained in Recoded DNA?

In molecular phylogenetics, it is typically assumed that the evolutionary process for DNA can be approximated by independent and identically distributed Markovian processes at the variable sites and that these processes diverge over the edges of a rooted bifurcating tree. Sometimes the nucleotides are transformed from a 4-state alphabet to a 3- or 2-state alphabet by a procedure that is called recoding, lumping, or grouping of states. Here, we introduce a likelihood-ratio test for lumpability for DNA that has diverged under different Markovian conditions, which assesses the assumption that the Markovian property of the evolutionary process over each edge is retained after recoding of the nucleotides. The test is derived and validated numerically on simulated data. To demonstrate the insights that can be gained by using the test, we assessed two published data sets, one of mitochondrial DNA from a phylogenetic study of the ratites (Syst. Biol. 59:90-107 [2010]) and the other of nuclear DNA from a phylogenetic study of yeast (Mol. Biol. Evol. 21:1455-1458 [2004]). Our analysis of these data sets revealed that recoding of the DNA eliminated some of the compositional heterogeneity detected over the sequences. However, the Markovian property of the original evolutionary process was not retained by the recoding, leading to some significant distortions of edge lengths in reconstructed trees.

Molecular phylogeny, historical biogeography and revised classification of andrenine bees (Hymenoptera: Andrenidae)

The mining bee subfamily Andreninae (Hymenoptera: Andrenidae) is a widely distributed and diverse group of ground-nesting solitary bees, including numerous species known to be important pollinators. Most of the species diversity of Andreninae is concentrated in the mainly Holarctic genus Andrena, comprising ca. 1550 described species. The subfamily and especially the genus have remained relatively neglected by recent molecular phylogenetic studies, with current classifications relying largely on morphological characters. We sampled ultraconserved element (UCE) sequences from 235 taxa, including all andrenine genera and 98 out of 104 currently recognized Andrena subgenera. Using 419,858 aligned nucleotide sites from 1009 UCE loci, we present a comprehensive molecular phylogenetic analysis of the subfamily. Our analysis supports the recognition of seven distinct genera in the Andreninae: Alocandrena, Ancylandrena, Andrena, Cubiandrena, Euherbstia, Megandrena, and Orphana. Within the genus Andrena, present-day subgeneric concepts revealed high degrees of paraphyly and polyphyly, due to strong homoplasy of morphological characters, necessitating a thorough, extensive revision of the higher classification of the genus. Based on our findings, we place the subgenus Calcarandrena in synonymy with Andrena (Lepidandrena); Hyperandrena, Nemandrena, Scoliandrena, Tylandrena and Zonandrena with A. (Melandrena); Distandrena, Fumandrena and Proxiandrena with A. (Micrandrena); Carandrena with A. (Notandrena); Agandrena with A. (Plastandrena); Xiphandrena with A. (Scrapteropsis); and Platygalandrena and Poliandrena with A. (Ulandrena) (new synonymies). We additionally reestablish the groups known as Opandrena and Truncandrena as valid subgenera of Andrena. Our results also show that the MRCA of Andrena+Cubiandrena dispersed from the New World to the Palaearctic probably during the Eocene-early Oligocene, followed by 10-14 Neogene dispersal events from the Palaearctic to the Nearctic and 1-6 Neogene dispersals back into the Palaearctic, all within the genus Andrena.

Partitioned Gene-Tree Analyses and Gene-Based Topology Testing Help Resolve Incongruence in a Phylogenomic Study of Host-Specialist Bees (Apidae: Eucerinae)

Incongruence among phylogenetic results has become a common occurrence in analyses of genome-scale data sets. Incongruence originates from uncertainty in underlying evolutionary processes (e.g., incomplete lineage sorting) and from difficulties in determining the best analytical approaches for each situation. To overcome these difficulties, more studies are needed that identify incongruences and demonstrate practical ways to confidently resolve them. Here, we present results of a phylogenomic study based on the analysis 197 taxa and 2,526 ultraconserved element (UCE) loci. We investigate evolutionary relationships of Eucerinae, a diverse subfamily of apid bees (relatives of honey bees and bumble bees) with >1,200 species. We sampled representatives of all tribes within the group and >80% of genera, including two mysterious South American genera, Chilimalopsis and Teratognatha. Initial analysis of the UCE data revealed two conflicting hypotheses for relationships among tribes. To resolve the incongruence, we tested concatenation and species tree approaches and used a variety of additional strategies including locus filtering, partitioned gene-trees searches, and gene-based topological tests. We show that within-locus partitioning improves gene tree and subsequent species-tree estimation, and that this approach, confidently resolves the incongruence observed in our data set. After exploring our proposed analytical strategy on eucerine bees, we validated its efficacy to resolve hard phylogenetic problems by implementing it on a published UCE data set of Adephaga (Insecta: Coleoptera). Our results provide a robust phylogenetic hypothesis for Eucerinae and demonstrate a practical strategy for resolving incongruence in other phylogenomic data sets.

The evolutionary history of the cellophane bee genus Colletes Latreille (Hymenoptera: Colletidae): Molecular phylogeny, biogeography and implications for a global infrageneric classification

Colletes Latreille (Hymenoptera: Colletidae) is a diverse genus with 518 valid species distributed in all biogeographic realms, except Australasia and Antarctica. Here we provide a comprehensive dated phylogeny for Colletes based on Bayesian and maximum likelihood-based analyses of DNA sequence data of six loci: 28S rDNA, cytochrome c oxidase subunit 1, elongation factor-1α copy F2, long-wavelength rhodopsin, RNA polymerase II and wingless. In total, our multilocus matrix consists of 4824 aligned base pairs for 143 species, including 112 Colletes species plus 31 outgroups (one stenotritid and a diverse array of colletids representing all subfamilies). Overall, analyses of each of the six single-locus datasets resulted in poorly resolved consensus trees with conflicting phylogenetic signal. However, our analyses of the multilocus matrix provided strong support for the monophyly of Colletes and show that it can be subdivided into five major clades. The implications of our phylogenetic results for future attempts at infrageneric classification for the Colletes of the world are discussed. We propose species groups for the Neotropical species of Colletes, the only major biogeographic realm for which no species groups have been proposed to date. Our dating analysis indicated that Colletes diverged from its sister taxon, Hemicotelles Toro and Cabezas, in the early Oligocene and that its extant lineages began diversifying only in the late Oligocene. According to our biogeographic reconstruction, Colletes originated in the Neotropics (most likely within South America) and then spread to the Nearctic very early in its evolutionary history. Geodispersal to the Old World occurred soon after colonization of the Northern Hemisphere. Lastly, the historical biogeography of Colletes is analyzed in light of available geological and palaeoenvironmental data.

Phylogeny and biogeography of the cleptoparasitic bee genus Epeolus (Hymenoptera: Apidae) and cophylogenetic analysis with its host bee genus Colletes (Hymenoptera: Colletidae)

The bee genus Epeolus Latreille (Hymenoptera: Apidae) consists of 109 species, which are known to be exclusively cleptoparasites of polyester (or cellophane) bees of the genus Colletes Latreille (Hymenoptera: Colletidae). Both genera have a nearly cosmopolitan distribution and are represented on all continents except Antarctica and Australia. We present the most comprehensive phylogeny for Epeolus to date, based on combined molecular and morphological data. In total, 59 ingroup taxa (species of Epeolus) and 7 outgroup taxa (other Epeolini) were scored for 99 morphological characters, and sequence data were obtained for seven genes (one mitochondrial and six nuclear, 5399 bp in total). Epeolus was found to be monophyletic, with a crown age estimated to be 25.0-13.4 Ma (95% HPD) and its origins traced to the Nearctic region. Epeolus was found to contain six major clades, five of which were well supported. The evolutionary history of Epeolus is explored in the context of earth history events and the evolutionary history of its host genus Colletes, for which a molecular phylogeny was constructed based on the same seven genes. A comparison of Epeolus and Colletes phylogenies limited to taxa for which there is evidence of an association suggests there was some cospeciation. However, more cladogenetic events in Epeolus were linked to instances of dispersal/vicariance. It is not yet clear the extent to which allopatric speciation contributed to diversification in Colletes, but the genus' success in having colonized and diversified across much of the globe made it possible for Epeolus to do the same.

A comparative study of the pharyngeal plate of Apoidea (Hymenoptera: Aculeata), with implications for the understanding of phylogenetic relationships of bees

The pharyngeal plate is a morphological complex with extensive anatomical variation among bees and, therefore, potential as a source of phylogenetic information. The pharyngeal plate of bees is divided into four morphologically distinct regions: sitophore, hypopharyngeal lobe, pharyngeal rods, and median oral plate. In this work we illustrate and document in detail for the first time the pharyngeal plate of 43 bee species, providing descriptions of the morphological variation and contrasting these findings with representatives of apoid wasps (Crabronidae and Sphecidae). We evaluate and discuss the potential of this structure as a rich source of morphological information in the context of bee phylogeny and any research potentially impacted by comparative morphological data. The shape of the hypopharyngeal lobe is highly variable among suprageneric taxa of bees and can be readily employed to characterise taxa at various levels. We argue that the global patterns in the variation of the pharyngeal plate can provide information for phylogenetic inference within bees and constructed and coded 10 characters that encompass the most noticeable morphological differences discussed herein.

Combining transcriptomes and ultraconserved elements to illuminate the phylogeny of Apidae

Two increasingly popular approaches to reconstruct the Tree of Life involve whole transcriptome sequencing and the target capture of ultraconserved elements (UCEs). Both methods can be used to generate large, multigene datasets for analysis of phylogenetic relationships in non-model organisms. While targeted exon sequencing across divergent lineages is now a standard method, it is still not clear if UCE data can be readily combined with published transcriptomes. In this study, we evaluate the combination of UCEs and transcriptomes in a single analysis using genome-, transcriptome-, and UCE data for 79 bees in the largest and most biologically diverse bee family, Apidae. Using existing tools, we first developed a workflow to assemble phylogenomic data from different sources and produced two large nucleotide matrices of combined data. We then reconstructed the phylogeny of the Apidae using concatenation- and coalescent-based methods, and critically evaluated the resulting phylogenies in the context of previously published genetic, genomic, and morphological data sets. Our estimated phylogenetic trees are robustly supported and largely congruent with previous molecular hypotheses, from deep nodes to shallow species-level phylogenies. Moreover, the combined approach allows us to resolve controversial nodes of the apid Tree of Life, by clarifying the relationships among the genera of orchid bees (Euglossini) and the monophyly of the Centridini. Additionally, we present novel phylogenetic evidence supporting the monophyly of the diverse clade of cleptoparasitic Apidae and the placement of two enigmatic, oil-collecting genera (Ctenoplectra and Tetrapedia). Lastly, we propose a revised classification of the family Apidae that reflects our improved understanding of apid higher-level relationships.

Seven remarkable new fossil species of parasitoid wasps (Hymenoptera, Ichneumonidae) from the Eocene Messel Pit

Parasitoid wasps of the family Ichneumonidae are one of the most diverse and species-rich groups of organisms with a worldwide distribution. We here describe seven new ichneumonid fossil species and two new genera from a remarkable insect fossil site, the Eocene Messel Pit in Germany (~47Ma). The unique fossil preservation allows us to place five out of the seven new species unequivocally in extant subfamilies and genera. For the first time, lobed claws which are a clear synapomorphy for the subfamily Pimplinae, are observed in a fossil, making the newly described Scambus fossilobus sp. nov. the oldest unequivocal representative of the group. We also describe a fossil of Labeninae (Trigonator macrocheirus gen. et sp. nov.), an ichneumonid subfamily that was until now believed to be an exclusively Gondwanan element. Furthermore, the newly described Rhyssella vera sp. nov., Xanthopimpla messelensis sp. nov., and X. praeclara sp. nov. provide evidence that these extant genera date back as far as the Early/Middle Eocene. In contrast to the clear placement of most of the newly described species, we were unable to place Polyhelictes bipolarus gen. et sp. nov. and Mesornatus markovici gen. et sp. nov. in an ichneumonid subfamily, mostly due to the high levels of homoplasy found in this group. These findings on the one hand demonstrate the need for a more rigorous approach in the taxonomic placement of fossil ichneumonids, and on the other hand provide more precise minimum ages for several ichneumonid genera and subfamilies.

Phylogeny, new generic-level classification, and historical biogeography of the Eucera complex (Hymenoptera: Apidae)

The longhorn bee tribe Eucerini (Hymenoptera: Apidae) is a diverse, widely distributed group of solitary bees that includes important pollinators of both wild and agricultural plants. About half of the species in the tribe are currently assigned to the genus Eucera and to a few other related genera. In this large genus complex, comprising ca. 390 species, the boundaries between genera remain ambiguous due to morphological intergradation among taxa. Using ca. 6700 aligned nucleotide sites from six gene fragments, 120 morphological characters, and more than 100 taxa, we present the first comprehensive molecular, morphological, and combined phylogenetic analyses of the 'Eucera complex'. The revised generic classification that we propose is congruent with our phylogeny and maximizes both generic stability and ease of identification. Under this new classification most generic names are synonymized under an expanded genus Eucera. Thus, Tetralonia, Peponapis, Xenoglossa, Cemolobus, and Syntrichalonia are reduced to subgeneric rank within Eucera, and Synhalonia is retained as a subgenus of Eucera. Xenoglossodes is reestablished as a valid subgenus of Eucera while Tetraloniella is synonymized with Tetralonia and Cubitalia with Eucera. In contrast, we suggest that the venusta-group of species, currently placed in the subgenus Synhalonia, should be recognized as a new genus. Our results demonstrate the need to evaluate convergent loss or gain of important diagnostic traits to minimize the use of potentially homoplasious characters when establishing classifications. Lastly, we show that the Eucera complex originated in the Nearctic region in the late Oligocene, and dispersed twice into the Old World. The first dispersal event likely occurred 24.2-16.6 mya at a base of a clade of summer-active bees restricted to warm region of the Old World, and the second 13.9-12.3 mya at the base of a clade of spring-active bees found in cooler regions of the Holarctic. Our results further highlight the role of Beringia as a climate-regulated corridor for bees.

Dispersal of thermophilic beetles across the intercontinental Arctic forest belt during the early Eocene

Massive biotic change occurred during the Eocene as the climate shifted from warm and equable to seasonal and latitudinally stratified. Mild winter temperatures across Arctic intercontinental land bridges permitted dispersal of frost-intolerant groups until the Eocene-Oligocene boundary, while trans-Arctic dispersal in thermophilic groups may have been limited to the early Eocene, especially during short-lived hyperthermals. Some of these lineages are now disjunct between continents of the northern hemisphere. Although Eocene climate change may have been one of the most important drivers of these ancient patterns in modern animal and plant distributions, its particular events are rarely implicated or correlated with group-specific climatic requirements. Here we explored the climatic and geological drivers of a particularly striking Neotropical-Oriental disjunct distribution in the rove beetle Bolitogyrus, a suspected Eocene relict. We integrated evidence from Eocene fossils, distributional and climate data, paleoclimate, paleogeography, and phylogenetic divergence dating to show that intercontinental dispersal of Bolitogyrus ceased in the early Eocene, consistent with the termination of conditions required by thermophilic lineages. These results provide new insight into the poorly known and short-lived Arctic forest community of the Early Eocene and its surviving lineages.

Comprehensive phylogeny, biogeography and new classification of the diverse bee tribe Megachilini: Can we use DNA barcodes in phylogenies of large genera?

Classification and evolutionary studies of particularly speciose clades pose important challenges, as phylogenetic analyses typically sample a small proportion of the existing diversity. We examine here one of the largest bee genera, the genus Megachile - the dauber and leafcutting bees. Besides presenting a phylogeny based on five nuclear genes (5480 aligned nucleotide positions), we attempt to use the phylogenetic signal of mitochondrial DNA barcodes, which are rapidly accumulating and already include a substantial proportion of the known species diversity in the genus. We used barcodes in two ways: first, to identify particularly divergent lineages and thus to guide taxon sampling in our nuclear phylogeny; second, to augment taxon sampling by combining nuclear markers (as backbone for ancient divergences) with DNA barcodes. Our results indicate that DNA barcodes bear phylogenetic signal limited to very recent divergences (3-4 my before present). Sampling within clades of very closely related species may be augmented using this technique, but our results also suggest statistically supported, but incongruent placements of some taxa. However, the addition of one single nuclear gene (LW-rhodopsin) to the DNA barcode data was enough to recover meaningful placement with high clade support values for nodes up to 15 million years old. We discuss different proposals for the generic classification of the tribe Megachilini. Finding a classification that is both in agreement with our phylogenetic hypotheses and practical in terms of diagnosability is particularly challenging as our analyses recover several well-supported clades that include morphologically heterogeneous lineages. We favour a classification that recognizes seven morphologically well-delimited genera in Megachilini: Coelioxys, Gronoceras, Heriadopsis, Matangapis, Megachile, Noteriades and Radoszkowskiana. Our results also lead to the following classification changes: the groups known as Dinavis, Neglectella, Eurymella and Phaenosarus are reestablished as valid subgenera of the genus Megachile, while the subgenus Alocanthedon is placed in synonymy with M. (Callomegachile), the subgenera Parachalicodoma and Largella with M. (Pseudomegachile), Anodonteutricharaea with M. (Paracella), Platysta with M. (Eurymella), and Grosapis and Eumegachile with M. (Megachile) (new synonymies). In addition, we use maximum likelihood reconstructions of ancestral geographic ranges to infer the origin of the tribe and reconstruct the main dispersal routes explaining the current, cosmopolitan distribution of this genus.

World-wide species distributions in the family Kyphosidae (Teleostei: Perciformes)

Sea chubs of the family Kyphosidae are major consumers of macroalgae on both temperate and tropical reefs, where they can comprise a significant proportion of fish biomass. However, the relationships and taxonomic status of sea chubs (including the junior synonyms Hermosilla, Kyphosus, Neoscorpis and Sectator) worldwide have long been problematical due to perceived lack of character differentiation, complicating ecological assessment. More recently, the situation has been further complicated by publication of conflicting taxonomic treatments. Here, we resolve the relationships, taxonomy and distribution of all known species of sea chubs through a combined analysis of partial fragments from mitochondrial markers (12s, 16s, cytb, tRNA -Pro, -Phe, -Thr and -Val) and three nuclear markers (rag1, rag2, tmo4c4). These new results provide independent evidence for the presence of several junior synonyms among Atlantic and Indo-Pacific taxa, demonstrating that several sea chub species are more widespread than previously thought. In particular, our results can reject the hypothesis of endemic species in the Atlantic Ocean. At a higher taxonomic level, our results shed light on the relationships between Girellidae, Kuhliidae, Kyphosidae, Microcanthidae, Oplegnathidae and Scorpididae, with Scorpididae resolved as the sister group to Kyphosidae.

Phylogenetic systematics and a revised generic classification of anthidiine bees (Hymenoptera: Megachilidae)

The bee tribe Anthidiini (Hymenoptera: Megachilidae) is a large, cosmopolitan group of solitary bees that exhibit intriguing nesting behavior. We present the first molecular-based phylogenetic analysis of relationships within Anthidiini using model-based methods and a large, multi-locus dataset (five nuclear genes, 5081 base pairs), as well as a combined analysis using our molecular dataset in conjunction with a previously published morphological matrix. We discuss the evolution of nesting behavior in Anthidiini and the relationship between nesting material and female mandibular morphology. Following an examination of the morphological characters historically used to recognize anthidiine genera, we recommend the use of a molecular-based phylogenetic backbone to define taxonomic groups prior to the assignment of diagnostic morphological characters for these groups. Finally, our results reveal the paraphyly of numerous genera and have significant consequences for anthidiine classification. In order to promote a classification system based on stable, monophyletic clades, we hereby make the following changes to Michener's (2007) classification: The subgenera Afranthidium (Zosteranthidium) Michener and Griswold, 1994, Afranthidium (Branthidium) Pasteels, 1969 and Afranthidium (Immanthidium) Pasteels, 1969 are moved into the genus Pseudoanthidium, thus forming the new combinations Pseudoanthidium (Zosteranthidium), Pseudoanthidium (Branthidium), and Pseudoanthidium (Immanthidium). The genus Neanthidium Pasteels, 1969 is also moved into the genus Pseudoanthidium, thus forming the new combination Pseudoanthidium (Neanthidium). Based on morphological characters shared with our new definition of the genus Pseudoanthidium, the subgenus Afranthidium (Mesanthidiellum) Pasteels, 1969 and the genus Gnathanthidium Pasteels, 1969 are also moved into the genus Pseudoanthidium, thus forming the new combinations Pseudoanthidium (Mesanthidiellum) and Pseudoanthidium (Gnathanthidium).