Resolving the species status of overlooked West‐Palaearctic bumblebees (original) (raw)
Related papers
Journal of European Taxonomy , 2020
Species are often presumed to be apparent in nature, but in practice they may be difficult to recognise, especially when viewed across continents rather than within a single site. Coalescent-based Poisson-tree-process (PTP) models applied to fast-evolving genes promise one quantitative criterion for recognising species, complete with the estimates of uncertainty that are required of a scientific method. Such methods face challenges especially in discerning between widespread polytypic species and complexes of closely related, restricted-range species. In particular, ‘over-sampling’ of many closely related individuals within one species could risk causing groups of less closely-related individuals within other species appearing relatively more distinct and consequently could risk them being interpreted falsely as separate species. Some of the most persistent taxonomic problems among bumblebees (genus Bombus Latreille, 1802) are within the subgenus Melanobombus von Dalla Torre, 1880. For a global revision of Melanobombus species, we use COI barcodes and seek to reduce the risk from localised over-sampling by filtering the data to include only unique haplotypes. Unique haplotypes give more conservative results than unfiltered data, but still increase the number of species in comparison with recent morphological treatments. After integrative assessment of COI coalescents in comparison with morphological groups, the number of accepted species shows a non-linear increase with sample size that plateaus to an increase of 47% (to 25 species) compared with a previous estimate (of 17) based on morphology alone. For the most widespread and variable species-complexes, our revised species improve the match to the patterns expected of species, both for genetic divergence-with-distance and for sympatry, leading to three main inferences. (1) The particularly widespread polytypic Bombus sichelii Radoszkowski, 1859, is a single species. (2) We detect two candidates for species within previous broad concepts of each of the former B. lapidarius (Linnaeus, 1758), B. miniatus Bingham, 1897, and B. rufofasciatus Smith, 1852. Within B. lapidarius s. lat. we find insufficient evidence to corroborate the candidate species, with no coalescent or morphological support for a recent claim for a separate species, B. bisiculus Lecocq, Biella, Martinet & Rasmont, 2019 described from southern Italy, but rather we find a weak and uncorroborated coalescent for a different and much broader group of samples from across southeastern Europe but excluding Turkey. Within the former broad concepts of B. miniatus s. lat. and B. rufofasciatus s. lat. the coalescent evidence is stronger and subtle evidence from morphology corroborates recognising B. miniatus s. str. and B. eurythorax Wang, 1892 stat. rev. as separate species as well as B. rufofasciatus s. str. and B. prshewalskyi Morawitz, 1880 stat. rev. as separate species. (3) Our coalescent and morphological results ‘split’ more clearly what has long been interpreted as a single polytypic B. keriensis Morawitz, 1887, s. lat., by supporting novel concepts of the restricted-range species: B. alagesianus Reinig, 1930 stat. rev., B. incertoides Vogt, 1911 stat. rev., B. keriensis s. str., B. qilianensis sp. nov., B. separandus Vogt, 1909 stat. rev., and B. tibeticus sp. nov. A lectotype is designated for the name B. keriensis and a neotype is designated for the name B. alagesianus. We estimate the phylogeny of Melanobombus species by including three slower-evolving genes to provide more evidence for deeper relationships, to estimate the time calibration of this phylogeny, and to estimate ancestral distributions, all within a Bayesian framework. We provide the first keys for identifying all of the species of Melanobombus.
Zoological Journal of the Linnean Society, 2011
Although bumblebees have received a lot of attention, some taxonomic problems have persisted for many years. One particularly obdurate case has been the species of the subgenus Subterraneobombus. We revise the bees of this subgenus by integrating evidence from both morphology and, for a 5% subsample, from DNA (cytochrome c oxidase subunit 1, CO1) barcodes from pinned museum specimens. We apply a reciprocal illumination procedure: (1) taxa recognized previously from morphology are used to stratify samples for DNA subsampling; (2) DNA barcodes from these subsamples are used to recognize groups of phylogenetically related specimens; and (3) for these groups, we reexamine morphological characters in order to recognize and diagnose species. A total of 3854 specimens from 1535 samples from across the geographic range of the subgenus throughout the Holarctic and northern Oriental regions are identified to 11 species. This includes one species newly recognized from Mongolia, Bombus mongolensis Williams sp. nov. Taxon concepts are modified substantially for four species, seven lectotypes are designated, and four new synonyms are recognized. The prevailing usage of Bombus distinguendus is maintained as valid by designating Bombus elegans as a nomen oblitum and designating B. distinguendus as a nomen protectum. Identification keys and colour-pattern diagrams are provided, and geographic distributions, elevational ranges, and phenological activity periods are described to characterize the species. An estimate of the biogeographic history is reconstructed with dispersal-vicariance analysis. In this study, DNA barcode data have been a cost-effective source of additional characters for diagnosing groups of specimens. The barcode data contributed directly to recognizing the one new species, of which females remain difficult to identify from morphology alone.
Systematic …, 2011
Many methods, based on morphological, molecular or chemical characters, have been used to address the question of species taxonomic status. Integrative taxonomy aims to define stronger supported taxonomic hypotheses by considering complementary datasets from different characters. By following an integrative approach, the present study includes molecular, chemical, and morphological criteria to establish the taxonomic status of two rare and doubtful cuckoo bumblebee taxa, Bombus (Psithyrus) barbutellus and Bombus (Psithyrus) maxillosus. These two sympatric taxa are discriminated by few morphological criteria (mainly wing darkness and hair length). We used these morphological character diagnoses to establish an a priori status of our samples (23 specimens). We developed a combined molecular dataset from one nuclear gene (EF-1α) and one mitochondrial gene (COI) spanning 1623 bp and a chemical dataset of sexual marking pheromones (73 compounds). The molecular data were subjected to maximum likelihood and Bayesian phylogenetic inference under partitioned model and maximum parsimony. The chemical data were analysed by clustering and the 2-group k-means method to test divergences between the two species. The resulting phylogenetic trees show no consistent divergence between the two taxa. Moreover, we found no divergence in the sexual marking pheromones in the clustering and 2-group k-means analyses. These converging results support the conspecificity of both taxa. Nonetheless, our determinations using the traditional morphological criteria separated our samples into two taxa. We conclude that the morphological criteria seem to relate to intraspecific variations. B. maxillosus is regarded as a syn.n. of B. barbutellus.
Diversity, 2022
A detailed phylogeny of bumblebees is urgently needed to understand speciation and biogeographic diversification in the Neotropical region. We sequenced autosomal and mtDNA loci from nine Brazilian bumblebee species and compiled it with the data already available to obtain highly resolved phylogenetic trees with fossil-calibrated dates. The ancestral Bombus lineage was estimated to diversify between 47.08 and 34.27 million years ago (Ma) in the Holarctic region, but largely restricted to the eastern Old World. The Neotropical region was initially colonized in the Late Miocene, where bumblebee diversification was shown to be consistent with geologic and climatic events of the Late Cenozoic. Neotropical bumblebees likely originated from Nearctic lineages, which dispersed towards South America after 29 Ma.
Zootaxa, 2016
The bumblebees of the subgenus Mendacibombus of the genus Bombus are the sister group to all other extant bumblebees and are unusual among bees for specialising in some of the highest elevation habitats with entomophilous plants on Earth. Most named taxa in this group (24 available names, from a total of 49 published names) were described originally from small differences in the colour pattern of the hair, many as parts (e.g. subspecies) of just one species. Subsequent taxonomic treatments recognised multiple species, but have described very few morphological characters, most of which are in the male genitalia. We examined 4413 specimens representing all of the named taxa from throughout the group's global range to describe variation in DNA, in skeletal morphology, and in the colour patterns of the hair. Using Bayesian inference of the phylogeny from an evolutionary model for the fast-evolving COI gene, and fitting either general mixed Yule/coalescent models or Poisson tree proc...
Apidologie, 2015
Here, we describe a new species of genus Bombus Latreille, 1802 from northeastern Brazil, Bombus (Thoracobombus) applanatus Oliveira, Françoso & Arias, sp. nov. Molecular analysis was initially performed to confirm the new species placement within the genus Bombus. Afterward, we performed an integrative approach combining molecular data (DNA barcoding and two nuclear regions) and morphology to confirm its taxonomic status. The genetic and morphological data were very consistent and congruent supporting this group as a new species. B. (Thoracobombus) applanatus Oliveira, Françoso & Arias, sp. nov. has the body totally covered by black pilosity and can be distinguished from closer and/or sympatric species by clypeus shape, which has a distinct flattened dorsal platform, by length of malar area and the length and shape of the hairs, shorter and aligned as if it was trimmed. In addition, brief taxonomic notes on Bombus (Thoracobombus) brevivillus Franklin (1913) and Bombus (Thoracobombus) morio Swederus (1787), the sympatric species, are provided. A key for identification of Brazilian Bombus species, including the new species, was elaborated.
A simplified subgeneric classification of the bumblebees (genusBombus)
Apidologie, 2008
A system of subgenera has been widely used for nearly a century to communicate ideas of relationships among bumblebee species. However, with 38 subgenera in recent lists for about 250 species, the system has come to be seen as too complicated. In this paper we suggest four criteria to guide the process of simplifying the subgeneric system, so that ideally subgenera should become: (1) monophyletic; (2) fewer; (3) diagnosable from morphology; and (4) names for important behavioural and ecological groups. Using a new strongly-supported estimate of phylogeny for almost all bumblebee species, we apply these criteria to reduce the system to 15 subgenera, and we assess the consequences. Ten new subgeneric synonyms are recognised. Keys to identify adult bumblebees to the simplified subgenera are provided for both sexes.
Annals of the Entomological Society of America, 1999
Traditionally, the genus Bombus (Apidae: Apinae: Bombini) is divided into several subgenera. This study derives an approximation of the relationships between 10 species of the subgenus Pyrobombus (from both Europe and North America), B. lapidarius L. and B. sichelii Radoszkowski from the subgenus Melanobombus, and B. terrestris L. from the subgenus Bombus s. str., by comparing the mitochondrial cytochrome b and cytochrome oxidase I (COI) genes. Although bootstrap values for deep branches are mostly low, the sequences show signiÞcant phylogenetic signal, low homoplasy, and all trees share some patterns that are consistent with those from other phylogenetic studies on bumblebees. These results show that the subgeneric names Pyrobombus and Melanobombus do not accurately reßect phylogeny, and therefore it would seem wise to revise the existing system into monophyletic species-groups or even ignore the subgeneric names altogether.