Well-supported Monophyletic Group Research Articles

Supplementary morphological data and molecular analyses of Eimeria labbeana (Labbé, 1896) Pinto, 1928 (Chromista: Miozoa: Eimeriidae) from columbiform birds in Portugal.

Columbiformes have a worldwide distribution, of which 166 species occur in Eurasia. They have been reported parasitized by coccidians recurrently in recent years; however, Eimeria labbeana (Labbé, 1896) Pinto, 1928, which is first Eimeria sp. from Columbiformes described in the late nineteenth century, is not taxonomically identified by its oocysts since the 1930s. In this context, the current study aimed to supplement the morphology of E. labbeana from Eurasian collared doves Streptopelia decaocto Frivaldszky, 1838 and from a common woodpigeon Columba palumbus Linnaeus, 1758 in Portugal, providing a preliminary genotypic characterization. Three of the four columbiforms were positive for oocysts identified as E. labbeana, which were morphologically revised as having micropyles, in addition to other minor adjustments. Oocysts from S. decaocto and C. palumbus were morphologically identical and equivalent in all morphometric aspects, besides having genotypic similarity of 99.5%. Phylogenetic analysis based on the mitochondrial cytochrome c oxidase subunit 1 gene resulted in a large clade with Eimeria spp. and Isospora spp. from different vertebrates and low similarity between Eimeria spp. from Columbiformes, whereas the phylogenetic analysis based on the small subunit ribosomal RNA gene resulted in well-supported monophyletic groups, including one with the coccidians of columbiform birds.

Morphological phylogenetic analyses and taxonomic revision of the Panorpa davidi group (Mecoptera: Panorpidae)

Abstract The Chinese Panorpa species without anal horn are normally assigned to the Panorpa davidi group. Here, we taxonomically revise the P. davidi group, which currently includes 17 known species and four new species: P. gaokaii sp. nov., P. huayuani sp. nov., P. uncinata sp. nov. and P. yaoluopingensis sp. nov. Panorpa shanyangensis Chou & Wang, 1981 and P. sexspinosa zhongnanensis Chou & Ran, 1981 are treated as junior synonyms of P. sexspinosa Cheng, 1949. We describe for the first time the male of P. stigmosa Zhou, 2006, and the females of P. curva Carpenter, 1938, P. davidi Navás, 1908, P. difficilis Carpenter, 1938, P. fructa Cheng, 1949, and P. jinchuana Hua, Sun & Li, 2001. A key to species of the group is provided. Phylogenetic analyses of maximum parsimony and maximum likelihood based on 79 morphological characters show that the newly defined P. davidi group is a well-supported monophyletic group and is sister to the genus Cerapanorpa Gao, Ma & Hua, 2016.

Morphological phylogenetic analyses and taxonomic revision of the Panorpa davidi group (Mecoptera: Panorpidae)

Abstract The Chinese Panorpa species without anal horn are normally assigned to the Panorpa davidi group. Here, we taxonomically revise the P. davidi group, which currently includes 17 known species and four new species: P. gaokaii sp. nov., P. huayuani sp. nov., P. uncinata sp. nov. and P. yaoluopingensis sp. nov. Panorpa shanyangensis Chou & Wang, 1981 and P. sexspinosa zhongnanensis Chou & Ran, 1981 are treated as junior synonyms of P. sexspinosa Cheng, 1949. We describe for the first time the male of P. stigmosa Zhou, 2006, and the females of P. curva Carpenter, 1938, P. davidi Navás, 1908, P. difficilis Carpenter, 1938, P. fructa Cheng, 1949, and P. jinchuana Hua, Sun & Li, 2001. A key to species of the group is provided. Phylogenetic analyses of maximum parsimony and maximum likelihood based on 79 morphological characters show that the newly defined P. davidi group is a well-supported monophyletic group and is sister to the genus Cerapanorpa Gao, Ma & Hua, 2016.

Diversity and emendation of the genus Planktoniella (Bacillariophyceae), with descriptions of P.tubulata sp. nov. and P.trifurcata sp. nov.

For the first time, LSU and SSU sequences were obtained from four species of the marine planktonic diatom Planktoniella. Samples were collected and cultured from Chinese coastal waters, and morphological observations were made using light and scanning electron microscopy. Combined morphological and DNA sequence data revealed two new species herein described as Planktoniella tubulata and Planktoniella trifurcata. Planktoniella tubulata is characterized by the prominent external tubes of two rimoportulae and the long external tubes of the marginal fultoportulae. The latter are organized regularly in a ring, externally on the mantle, and protrude parallel to the valvar plane. Planktoniella trifurcata is unique in having mucilaginous extensions that usually expand into three lobes, and external extensions of the marginal fultoportulae being either tubes or spines. In the phylogenetic analyses inferred from SSU and LSU sequences, the four analyzed Planktoniella taxa formed a well-supported monophyletic group. A suite of three characters, mucilage membranes or wings, two marginal rimoportulae, and mantle ribs are diagnostic for Planktoniella. Based on these detailed ultrastructural observations, the description of Planktoniella is emended.

Evaluating the monophyly of Mammillaria series Supertextae (Cactaceae).

Mammillaria (Cactaceae) taxonomy has been historically problematic due to the morphological variability and sympatry of the species. This has led to several proposals for infrageneric classification, including subgeneric, section and series categories. Mammillaria ser. Supertextae is one of 15 series and is made up of a variable set of species that are mainly distributed in southern Mexico and Central America. However, the phylogenetic relationships within M. ser. Supertextae and its relationship to other Mammillaria taxa are far from fully understood. Here we attempt to elucidate these relationships using complete terminal sampling and newly obtained chloroplast marker sequences and comparing them to Mammillaria species sequences from GenBank. Our phylogenetic analyses showed that M. ser. Supertextae comprises a well-supported monophyletic group that diverged approximately 2.1 Mya and has M. ser. Polyacanthae as its sister group; however, relationships within M. ser. Supertextae remain unresolved. The topology obtained within M. ser. Supertextae must also be interpreted under the distribution shared by these taxa, but it is difficult to differentiate ancestral polymorphisms from possible introgression, given the short time elapsed and the markers used. Our results show that the infrageneric units of M. haageana and M. albilanata can be considered independent evolutionary units. We also suggest that the relationship between M. haageana and M. albilanata is convoluted because their distribution overlaps (mainly towards southern Mexico), with genetic differences that possibly indicate they represent more than two taxonomic entities. One possible explanation is that there could still be gene flow between these taxa, and we might be witnessing an ongoing speciation process.

THE VIOLETS OF THE BRAZILIAN SAVANNA: A REVISION OF THE POMBALIA LANATA COMPLEX (VIOLACEAE), WITH DESCRIPTIONS OF TWO NEW SPECIES

Pombalia Vand. (Violaceae) is represented in the Cerrado by a well-supported monophyletic group of species known as the Pombalia lanata complex, characterised by some unique vegetative and reproductive features within the genus. This group includes six species – Pombalia cristalina, P. insignis, P. lanata, P. poaya, P. strigoides and P. velutina – the first two of which are new to science. Pombalia lanata shows the widest geographical distribution throughout the Central Brazilian Plateau and the Espinhaço Range in Minas Gerais state, with a disjunction in Misiones Province, Argentina. Because most species in this group are narrow endemics, we evaluated the conservation status of all taxa. An identification key for the species, descriptions, illustrations, maps of geographical distribution and nomenclatural notes are also provided.

(2806) Proposal to conserve the name Cistus violaceus (Helianthemum violaceum) against C. racemosus (Cistaceae)

(2806) Proposal to conserve the name <i>Cistus violaceus</i> (<i>Helianthemum violaceum</i>) against <scp><i>C</i>. <i>racemosus</i></scp> (<i>Cistaceae</i>)

Phylogenetic partitioning of the third-largest vertebrate genus in the world, Cyrtodactylus Gray, 1827 (Reptilia; Squamata; Gekkonidae) and its relevance to taxonomy and conservation

The gekkonid genus Cyrtodactylus is the third most speciose vertebrate genus in the world, containing well over 300 species that collectively range from South Asia to Melanesia across some of the most diverse landscapes and imperiled habitats on the planet. A genus-wide phylogeny of the group has never been presented because researchers working on different groups were using different genetic markers to construct phylogenies that could not be integrated. We present here Maximum likelihood and Bayesian inference mitochondrial and mito-nuclear phylogenies incorporating of 310 species that include dozens of species that had never been included in a genus-wide analysis. Based on the mitochondrial phylogeny, we partition Cyrtodactylus into 31 well-supported monophyletic species groups which, if used as recommended herein, will increase the information content of future integrative taxonomic analyses that continue to add new species to this genus at an ever-increasing annual rate. Data presented here reiterate the outcome of several previous studies indicating that Cyrtodactylus comprises an unprecedented number of narrow-range endemics restricted to single mountain tops, small islands, or karst formations that still remain unprotected. This phylogeny can provide a platform for various comparative ecological studies that can be integrated with conservation management programs across the broad diversity of landscapes and habitats occupied by this genus. Additionally, these data indicate that the true number of Cyrtodactylus remains substantially underrepresented.

Phylogenetic partitioning of the third-largest vertebrate genus in the world, Cyrtodactylus Gray, 1827 (Reptilia; Squamata; Gekkonidae) and its relevance to taxonomy and conservation

The gekkonid genus Cyrtodactylus is the third most speciose vertebrate genus in the world, containing well over 300 species that collectively range from South Asia to Melanesia across some of the most diverse landscapes and imperiled habitats on the planet. A genus-wide phylogeny of the group has never been presented because researchers working on different groups were using different genetic markers to construct phylogenies that could not be integrated. We present here Maximum likelihood and Bayesian inference mitochondrial and mito-nuclear phylogenies incorporating of 310 species that include dozens of species that had never been included in a genus-wide analysis. Based on the mitochondrial phylogeny, we partition Cyrtodactylus into 31 well-supported monophyletic species groups which, if used as recommended herein, will increase the information content of future integrative taxonomic analyses that continue to add new species to this genus at an ever-increasing annual rate. Data presented here reiterate the outcome of several previous studies indicating that Cyrtodactylus comprises an unprecedented number of narrow-range endemics restricted to single mountain tops, small islands, or karst formations that still remain unprotected. This phylogeny can provide a platform for various comparative ecological studies that can be integrated with conservation management programs across the broad diversity of landscapes and habitats occupied by this genus. Additionally, these data indicate that the true number of Cyrtodactylus remains substantially underrepresented.

Human Enterovirus Diversity by Next-Generation Sequencing Analysis in Urban Sewage Samples From Buenos Aires Metropolitan Area, Argentina: A Retrospective Study.

Human Enteroviruses (hEVs) are responsible for a wide variety of human diseases. During hEVs infection, virions are excreted in human feces and the fecal-oral route is the primary pathway for person-to-person transmission. Sewage surveillance could help in monitoring hEVs circulation and describing their diversity in a specific population. In this study, sewage samples collected in Buenos Aires Metropolitan Area (Argentina) were retrospectively studied through an amplicon-deep sequencing approach and phylogenetic analyses to characterize hEVs spread. We identified 17 different hEVs types belonging to A, B, and C species. To the best of our knowledge, this is the first report in Buenos Aires for 7 identified hEV-C types. Phylogenetic analyses suggest several introductions of coxsackievirus B4, echovirus 1, and echovirus 9 in the country, along with the national spread reached by some variants. Besides, well-supported monophyletic groups of Argentine, Uruguayan, and Brazilian strains unveiled regional circulation patterns for some variants. These results extend our knowledge about hEVs circulation in Buenos Aires and might exhort authorities to implement more active sewage surveillance in the region.

Euglenozoa: taxonomy, diversity and ecology, symbioses and viruses.

Euglenozoa is a species-rich group of protists, which have extremely diverse lifestyles and a range of features that distinguish them from other eukaryotes. They are composed of free-living and parasitic kinetoplastids, mostly free-living diplonemids, heterotrophic and photosynthetic euglenids, as well as deep-sea symbiontids. Although they form a well-supported monophyletic group, these morphologically rather distinct groups are almost never treated together in a comparative manner, as attempted here. We present an updated taxonomy, complemented by photos of representative species, with notes on diversity, distribution and biology of euglenozoans. For kinetoplastids, we propose a significantly modified taxonomy that reflects the latest findings. Finally, we summarize what is known about viruses infecting euglenozoans, as well as their relationships with ecto- and endosymbiotic bacteria.

Calling for a reassessment of rodent diversity in Colombia: description of a new species of Neacomys (Cricetidae: Oryzomyini) from the Magdalena Valley, with a new phylogenetic hypothesis for the genus and comments on its diversification.

Neacomys Thomas, 1900 is an oryzomyine genus comprising at least 17 lineages distributed from easternmost Panama to northern Bolivia. As is the case for other groups of the subfamily Sigmodontinae, Neacomys have experienced a substantial increase in the rate of species descriptions in the last two decades, prompted by the progressive generation of morphological, molecular and karyological data. Nevertheless, most of the studies related to the genus have focused on the assessment of Cis-Andean populations, so that the Trans-Andean ones have been relegated to the background. In more than a century, only two species have been described from that region, one of them present in Colombia (N. tenuipes Thomas, 1900). Here, a new species of Neacomys is named and described based on samples collected in montane ecosystems of the Serranía de los Yariguíes, an isolated massif in the Magdalena Valley (Trans-Andean Colombia). Its validity is supported by a unique combination of morphological and molecular characters: Neacomys sp. nov. can be distinguished from other congeners mainly by the presence of broad ochraceous-orange patches on the sides of the muzzle, a gray-based ochraceous buff ventral fur, a thick hamular process of the squamosal, an opened ectotympanic ring, and a narrow anterocone of M1. The species is recovered as a clearly divergent and well-supported monophyletic group in the phylogenies, which implies it is not closely related to any other species in the genus and probably represents an early radiation within it. The new species of Neacomys constitutes the only rodent described from Colombia in more than 50 years and brings the list of mammals of the country to 529 species. Its discovery evidences that Trans-Andean region could be an important source of hidden diversity for the genus, and in Colombia, for rodents in general. Thus, further inventories, especially into remote areas, are needed to unveil this diversity. The fact that the new species seems to be endemic to an isolated mountain range implies it merits attention in terms of conservation.

Multigene phylogenetics of euglenids based on single-cell transcriptomics of diverse phagotrophs

Euglenids are a well-known group of single-celled eukaryotes, with phototrophic, osmotrophic and phagotrophic members. Phagotrophs represent most of the phylogenetic diversity of euglenids, and gave rise to the phototrophs and osmotrophs, but their evolutionary relationships are poorly understood. Symbiontids, in contrast, are anaerobes that are alternatively inferred to be derived euglenids, or a separate euglenozoan group. Most phylogenetic studies of euglenids have examined the SSU rDNA only, which is often highly divergent. Also, many phagotrophic euglenids (and symbiontids) are uncultured, restricting collection of other molecular data. We generated transcriptome data for 28 taxa, mostly using a single-cell approach, and conducted the first multigene phylogenetic analyses of euglenids to include phagotrophs and symbiontids. Euglenids are recovered as monophyletic, with symbiontids forming an independent branch within Euglenozoa. Spirocuta, the clade of flexible euglenids that contains both the phototrophs (Euglenophyceae) and osmotrophs (Aphagea), is robustly resolved, with the ploeotid Olkasia as its sister group, forming the new taxon Olkaspira. Ploeotids are paraphyletic, although Ploeotiidae (represented by Ploeotia spp.), Lentomonas, and Keelungia form a robust clade (new taxon Alistosa). Petalomonadida branches robustly as sister to other euglenids in outgroup-rooted analyses. Within Spirocuta, Euglenophyceae is a robust clade that includes Rapaza, and Anisonemia is a well-supported monophyletic group containing Anisonemidae (Anisonema and Dinema spp.), ‘Heteronema II’ (represented by H. vittatum), and a clade of Neometanema plus Aphagea. Among ‘peranemid’ phagotrophs, Chasmostoma branches with included Urceolus, and Peranema with the undescribed ‘Jenningsia II’, while other relationships are weakly supported and consequently the closest sister group to Euglenophyceae remains unresolved. Our results are inconsistent with recent inferences that Entosiphon is the evolutionarily pivotal sister either to other euglenids, or to Spirocuta. At least three transitions between posterior and anterior flagellar gliding occurred in euglenids, with the phylogenetic positions and directions of those transitions remaining ambiguous.

Genetic diversity and recombination between turnip yellows virus strains in Australia.

Disease outbreaks caused by turnip yellows virus (TuYV), a member of the genus Polerovirus, family Luteoviridae, regularly occur in canola and pulse crops throughout Australia. To understand the genetic diversity of TuYV for resistance breeding and management, genome sequences of 28 TuYV isolates from different hosts and locations were determined using high-throughput sequencing (HTS). We aimed to identify the parts of the genome that were most variable and clarify the taxonomy of viruses related to TuYV. Poleroviruses contain seven open reading frames (ORFs): ORF 0-2, 3a, and 3-5. Phylogenetic analysis based on the genome sequences, including isolates of TuYV and brassica yellows virus (BrYV) from the GenBank database, showed that most genetic variation among isolates occurred in ORF 5, followed by ORF 0 and ORF 3a. Phylogenetic analysis of ORF 5 revealed three TuYV groups; P5 group 1 and group 3 shared 45-49% amino acid sequence identity, and group 2 is a recombinant between the other two. Phylogenomic analysis of the concatenated ORFs showed that TuYV is paraphyletic with respect to BrYV, and together these taxa form a well-supported monophyletic group. Our results support the hypothesis that TuYV and BrYV belong to the same species and that the phylogenetic topologies of ORF 0, 3a and 5 are incongruent and may not be informative for species demarcation. A number of beet western yellow virus (BWYV)- and TuYV-associated RNAs (aRNA) were also identified by HTS for the first time in Australia.

Lake Poso's shrimp fauna revisited: the description of five new species of the genus Caridina (Crustacea, Decapoda, Atyidae) more than doubles the number of endemic lacustrine species.

Lake Poso, an ancient lake system on the Indonesian island Sulawesi, harbours an endemic species flock of six, four lacustrine and two riverine species of the freshwater shrimp genus Caridina. In this study, five new lacustrine species are described, bringing the total to eleven species altogether. The number of lacustrine species is more than doubled to nine species compared to the last taxonomic revision in 2009. One of them, Caridina mayamareenae Klotz, Wowor & von Rintelen, sp. nov., even represents the first case of an atyid shrimp associated with freshwater snails which is morphologically adapted to living in shells. An integrative approach was used by providing a combination of morphological, ecological, and molecular data. Based on standard morphological characters, distribution, substrate preferences, and colouration of living specimens in the field, five distinct undescribed species could be distinguished. To support our species-hypothesis based on the mitochondrial genes 16S and COI, a molecular phylogeny was used for all eleven species from Lake Poso. All species form a well-supported monophyletic group, but only four morphospecies consistently correspond to mtDNA clades – a possible reason could be introgressive hybridisation, incomplete lineage sorting, or not yet fixed species boundaries. These results are discussed further in the context of adaptive radiation, which turned out to be more diverse than previously described. Finally, yet importantly, subjecting all new species to similar threats and to the same IUCN category and criterion than the previously described species from the lake is recommended.

Phylogenetic placement of Iodosphaeriaceae (Xylariales, Ascomycota), designation of an epitype for the type species of Iodosphaeria, I. phyllophila, and description of I. foliicola sp. nov.

The Iodosphaeriaceae is represented by the single genus, Iodosphaeria, which is composed of nine species with superficial, black, globose ascomata covered with long, flexuous, brown hairs projecting from the ascomata in a stellate fashion, unitunicate asci with an amyloid apical ring or ring lacking and ellipsoidal, ellipsoidal-fusiform or allantoid, hyaline, aseptate ascospores. Members of Iodosphaeria are infrequently found worldwide as saprobes on various hosts and a wide range of substrates. Only three species have been sequenced and included in phylogenetic analyses, but the type species, I. phyllophila, lacks sequence data. In order to stabilize the placement of the genus and family, an epitype for the type species was designated after obtaining ITS sequence data and conducting maximum likelihood and Bayesian phylogenetic analyses. Iodosphaeria foliicola occurring on overwintered Alnus sp. leaves is described as new. Five species in the genus form a well-supported monophyletic group, sister to the Pseudosporidesmiaceae in the Xylariales. Selenosporella-like and/or ceratosporium-like synasexual morphs were experimentally verified or found associated with ascomata of seven of the nine accepted species in the genus. Taxa included and excluded from Iodosphaeria are discussed.

Taxonomic review of the species of Parkinsonia (Leguminosae, Caesalpinioideae) from the Americas

Abstract The genus Parkinsonia has a pantropical distribution with 12 species globally, occurring mainly in arid and semi-arid climate environments. Many taxonomic studies have considered Parkinsonia as a distinct genus of Cercidium, but phylogenetic analyses do not support this distinction because, when together, they form a well-supported monophyletic group. The aim of this study was to review the taxonomy of Parkinsonia species from the Americas. We examined 400 specimens deposited in herbaria, original diagnoses, and types. We present here morphological descriptions, identification key, taxonomic notes and nomenclatural notes, ecology and conservation status, reproductive phenological states, distribution maps and drawings for each species in this treatment. Our study points out eight species of Parkinsonia for the Americas (P. aculeata, P. andicola, P. florida, P. glauca, P. microphylla, P. peruviana, P. praecox, and P. texana), three new synonyms of Parkinsonia (Cercidium macrum, P. inermis, and P. texana var. macra) and six new lectotypifications (Cercidium plurifoliolatum, C. spinosum, P. inermis, P. microphylla, P. praecox, P. texana). The main diagnostic characteristics are green or gray stem, branches generally with thorns, reduced leaves (pinnate appearance) or not reduced (bipinnate), hyphodromous venation, racemose inflorescences, yellow petals and moniliform or flat pod fruit.

Evolution of H9N2 avian influenza viruses in Iran, 2017-2019.

Since its first detection in 1998, avian influenza virus (AIV) subtype H9N2 has been enzootic in Iran. To better understand the evolutionary history of H9N2 viruses in Iran, we sequenced 15 currently circulating H9N2 viruses from domestic poultry during 2017-2019 and performed phylogenetic analysis of complete genome sequences. Phylogenetic analyses indicated that the Iranian H9N2 viruses formed multiple well-supported monophyletic groups within the G1-lineage of H9N2 virus. Our analysis of viral population dynamics revealed an increase in genetic diversity until 2007, corresponding to the multiple introductions and diversification of H9N2 viruses into multiple genetic groups (named Iran 1-4 subgroups), followed by a sudden decrease after 2008. Only the Iran 4 subgroup has survived, expanded, and currently circulates in Iran. The H9N2 viruses possessed many molecular markers associated with mammalian adaption in all gene segments, except neuraminidase gene. Considering the presence of mammalian host-specific markers, the public health threat of H9N2 viruses continues. Molecular analysis showed that Iranian H9N2 strains have continued to evolve and recent strains have multiple amino acid changes and addition of potential N-glycosylation on the antigenic sites of haemagglutinin. Continued antigenic and molecular surveillance of H9N2 viruses in poultry and mammals would be required to monitor further increments in viral evolution and their potential threat to public health.

Ancient DNA Suggests Single Colonization and Within-Archipelago Diversification of Caribbean Caviomorph Rodents.

Reconstructing the evolutionary history of island biotas is complicated by unusual morphological evolution in insular environments. However, past human-caused extinctions limit the use of molecular analyses to determine origins and affinities of enigmatic island taxa. The Caribbean formerly contained a morphologically diverse assemblage of caviomorph rodents (33 species in 19 genera), ranging from ∼0.1 to 200 kg and traditionally classified into three higher-order taxa (Capromyidae/Capromyinae, Heteropsomyinae, and Heptaxodontidae). Few species survive today, and the evolutionary affinities of living and extinct Caribbean caviomorphs to each other and to mainland taxa are unclear: Are they monophyletic, polyphyletic, or paraphyletic? We use ancient DNA techniques to present the first genetic data for extinct heteropsomyines and heptaxodontids, as well as for several extinct capromyids, and demonstrate through analysis of mitogenomic and nuclear data sets that all sampled Caribbean caviomorphs represent a well-supported monophyletic group. The remarkable morphological and ecological variation observed across living and extinct caviomorphs from Cuba, Hispaniola, Jamaica, Puerto Rico, and other islands was generated through within-archipelago evolutionary radiation following a single Early Miocene overwater colonization. This evolutionary pattern contrasts with the origination of diversity in many other Caribbean groups. All living and extinct Caribbean caviomorphs comprise a single biologically remarkable subfamily (Capromyinae) within the morphologically conservative living Neotropical family Echimyidae. Caribbean caviomorphs represent an important new example of insular mammalian adaptive radiation, where taxa retaining “ancestral-type” characteristics coexisted alongside taxa occupying novel island niches. Diversification was associated with the greatest insular body mass increase recorded in rodents and possibly the greatest for any mammal lineage.

DNA barcoding and hypopygium shape support delimitation of sympatric Dissomphalus species (Hymenoptera, Bethylidae) from the Atlantic rainforest.

Dissomphalus is a cosmopolitan genus of Bethylidae and has 269 Neotropical species divided into 32 species-groups, mostly defined by the genital and the tergal process structures. Dissomphalus rectilineus and D. concavatus are sympatric species in the ulceratus species-group. Members of the species-group share many similarities in the morphology of the head, hypopygium, tergal process and genitalia, but may be distinguished by the structure of the hypopygium. Previous studies have found intermediate structures of the hypopygium in the sympatric areas and raised questions about the distinctiveness of these two species. We sequenced 340 bp of the mitochondrial gene cytochrome oxidase I of 29 specimens from Brazil and Paraguay, calculated the genetic divergence among specimens, and recovered the phylogenetic relationships between taxa. In addition, we compared the morphology of the hypopygium to evaluate its use as a species-specific diagnostic character using the genetic divergence values. We recovered three well-supported monophyletic groups (intraclade divergence from 1.3 to 13.4%) and three hypopygium morphologies associated with each clade, two of them associated with D. rectilineus and D. concavatus (as described in the literature); the third one is new, not associated with any known species. The divergence between the D. rectilineus and D. concavatus clades was 19%, while the third clade is divergent from each species by 19–20%. If fully described, the hypopygium shape associated with the COI sequence will represent an extremely promising approach to the diagnosis of Dissomphalus species.