Widespread Genus Research Articles

A Revised Phylogenetic Classification for Viola (Violaceae).

The genus Viola (Violaceae) is among the 40–50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then-known 400 species were distributed among 14 sections and numerous unranked groups. Here, we provide an updated, comprehensive classification of the genus, based on data from phylogeny, morphology, chromosome counts, and ploidy, and based on modern principles of monophyly. The revision is presented as an annotated global checklist of accepted species of Viola, an updated multigene phylogenetic network and an ITS phylogeny with denser taxon sampling, a brief summary of the taxonomic changes from Becker’s classification and their justification, a morphological binary key to the accepted subgenera, sections and subsections, and an account of each infrageneric subdivision with justifications for delimitation and rank including a description, a list of apomorphies, molecular phylogenies where possible or relevant, a distribution map, and a list of included species. We distribute the 664 species accepted by us into 2 subgenera, 31 sections, and 20 subsections. We erect one new subgenus of Viola (subg. Neoandinium, a replacement name for the illegitimate subg. Andinium), six new sections (sect. Abyssinium, sect. Himalayum, sect. Melvio, sect. Nematocaulon, sect. Spathulidium, sect. Xanthidium), and seven new subsections (subsect. Australasiaticae, subsect. Bulbosae, subsect. Clausenianae, subsect. Cleistogamae, subsect. Dispares, subsect. Formosanae, subsect. Pseudorupestres). Evolution within the genus is discussed in light of biogeography, the fossil record, morphology, and particular traits. Viola is among very few temperate and widespread genera that originated in South America. The biggest identified knowledge gaps for Viola concern the South American taxa, for which basic knowledge from phylogeny, chromosome counts, and fossil data is virtually absent. Viola has also never been subject to comprehensive anatomical study. Studies into seed anatomy and morphology are required to understand the fossil record of the genus.

Mixotrophy in the bloom-forming genus Phaeocystis and other haptophytes

Phaeocystis is a globally widespread marine phytoplankton genus, best known for its colony-forming species that can form large blooms and odorous foam during bloom decline. In the North Sea, Phaeocystis globosa typically becomes abundant towards the end of the spring bloom, when nutrients are depleted and the share of mixotrophic protists increases. Although mixotrophy is widespread across the eukaryotic tree of life and is also found amongst haptophytes, a mixotrophic nutrition has not yet been demonstrated in Phaeocystis. Here, we sampled two consecutive Phaeocystis globosa spring blooms in the coastal North Sea. In both years, bacterial cells were observed inside 0.6 – 2% of P. globosa cells using double CARD-FISH hybridizations in combination with laser scanning confocal microscopy. Incubation experiments manipulating light and nutrient availability showed a trend towards higher occurrence of intracellular bacteria under P-deplete conditions. Based on counts of bacteria inside P. globosa cells in combination with theoretical values of prey digestion times, maximum ingestion rates of up to 0.08 bacteria cell−1 h−1 were estimated. In addition, a gene-based predictive model was applied to the transcriptome assemblies of seven Phaeocystis strains and 24 other haptophytes to assess their trophic mode. This model predicted a phago-mixotrophic feeding strategy in several (but not all) strains of P. globosa, P. antarctica and other haptophytes that were previously assumed to be autotrophic. The observation of bacterial cells inside P. globosa and the gene-based model predictions strongly suggest that the phago-mixotrophic feeding strategy is widespread among members of the Phaeocystis genus and other haptophytes, and might contribute to their remarkable success to form nuisance blooms under nutrient-limiting conditions.

Phylogenomics of the Caribbean melocacti: Cryptic species and multiple invasions

AbstractThe widespread Neotropical genus Melocactus of approximately 42 currently recognized species, is most diverse in eastern Brazil and the Greater Antilles, especially Cuba. Species delimitation is notoriously problematic in the group, although this is due in part to a lack of detailed systematic studies, as well as a severely cluttered nomenclatural history. To date, no comprehensive phylogenetic hypotheses have been generated for the clade, although some population genetic and morphological studies exist. We generated the largest phylogenetic dataset of Melocactus to date based on plastome data derived from a genome‐skimming approach for 26 taxa, which provided a framework for understanding species limits and relationships among Caribbean species. Our time‐calibrated phylogeny revealed a mid‐Pleistocene origin for Melocactus, and we resolved three major clades, a Cuban clade, a mostly South American clade, and a widespread Caribbean clade, which also included some South American taxa. Our topology recovered the Cuban clade as sister to the rest of the species, although this placement was poorly supported, and several other Cuban species are scattered throughout the rest of the tree. Biogeographic analyses suggested multiple dispersal events from South America leading to the current diversity on Cuba, as well as other parts of the Antilles. Based on our phylogenetic results, previous hypotheses of species numbers and relationships in the Caribbean generated solely on morphology have, in some cases, been greatly underestimated. Our study shows that plastome data are effective for resolving clades and species limits in Melocactus, although future work will need to include broader sampling and larger datasets to fully resolve relationships in this complicated group of cacti. We describe one new cryptic species for Cuba, Melocactus santiagoensis sp. nov., and provide a new combination (Melocactus lagunaensis comb. & stat. nov.), based on our phylogenetic results and morphological data and typify numerous names in the genus. The genus Melocactus is another striking example of the exceptional diversity that has been generated in the poorly studied, seasonally dry tropical forest of the Greater Antilles.

A review of species of the genus Mocyta (Coleoptera, Staphylinidae) in Ukraine

A review of the genus Mocyta Mulsant & Rey, 1874, which is represented in Ukraine; a description of the main morphological features and diagnostic features is made, data on ecological features, seasonal activity of adults, the distribution of representatives of the genus in Ukraine and the world and the keys to identify the species are presented. The information on the distribution of species of the genus Mocyta in the territory of Ukraine has been clarified and significantly supplemented by new findings. The results can be used to address a number of theoretical issues of faunistics, zoogeography, and ecology, as well as in compiling the inventory of the fauna of the Ukrainian Carpathians, for comparative faunal research, in the analysis of species distribution, in biogeographic constructions, studies of faunogenesis, ecological monitoring and prediction of consequences of the influence of human activities on natural ecosystems of the region. The genus Mocyta is a widespread genus, which in terms of the combination of morphological and biological features belongs to the tribe Athetini Casey, 1910 of the subfamily Aleocharinae Fleming, 1821 of the family Staphylinidae Latreille, 1802. There are 26 known species in the fauna of Palearctic, 5 of which (Mocyta clientula, M. fungi fungi, M. fussi, M. orbata, M. orphana) are represented in the fauna of Ukraine. However, it is likely that there are two more species (M. amplicollis and M. negligens), identified for the surrounding areas, for which characteristics and comparative diagnoses have also been provided. This paper is a continuation of the initiated series of reviews of genera and species of the tribe Athetini of the fauna of Ukraine. Taking into account the wide geographical distribution and significant individual variability in size, colour and shape of the spermatheca of representatives of the genus, the identification of the latter presents some significant difficulties.

Out of southern Africa: Origins and cryptic speciation in Chamaeleo, the most widespread chameleon genus

Molecular phylogenetics and the application of species delimitation methods have proven useful in addressing limitations associated with morphology based taxonomy and have highlighted the inconsistencies in the current taxonomy for many groups. For example, the genus Chamaeleo, which comprises 14 species with large distributions across mainland Africa and parts of Eurasia, exhibits relatively minor phenotypic differentiation between species, leading to speculation regarding the presence of cryptic diversity in the genus. Therefore, the aims of the present study were to construct a robust and comprehensive phylogeny of the genus and highlight potential species-level cryptic diversity. Additionally, we sought to ascertain the most likely biogeographic origin of the genus and understand its spatio-temporal diversification. Accordingly, we made use of species delimitation methods (Bayesian and divergence based) to investigate the extent of cryptic diversity in Chamaeleo, and applied an ancestral area reconstruction to examine the biogeographic origin of the group. Our phylogenetic analyses suggested the presence of at least 18 taxa within Chamaeleo. Notably, three taxa could be recognised within C. dilepis, none of which are equivalent in context with any of the currently described subspecies. There were also three taxa within C. gracilis and two within C. anchietae. The single available tissue specimen identified as C. necasi was embedded within the C. gracilis clade. Our ancestral area reconstruction points to a southern African/Zambezian origin for Chamaeleo, with diversification beginning during the cooling and aridification of Africa that characterised the Oligocene Epoch, ca. 34–23 Mya (Million years ago). Species-level diversification began in the Miocene Epoch (ca. 23–5 Mya), possibly tracking the aridification that triggered the shift from forest to more open, mesic savanna for most clades, but with tectonic events influencing speciation in a Palearctic clade. These findings lay the foundation for a future integrative taxonomic re-evaluation of Chamaeleo, which will be supported with additional lines of evidence before implementing any taxonomic changes.

Seven snail species hidden in one: Biogeographic diversity in an apparently widespread periwinkle in the Southern Ocean

AbstractAimThe Antarctic Circumpolar Current imparts significant structure to the Southern Ocean biota. The Antarctic Polar Front is a major barrier to dispersal, with separate species (or sometimes intraspecific clades) normally occurring either side of this feature. We examined the biogeographic structure of an apparent exception to this rule in a widespread genus of the Southern Ocean, the periwinkle snail, Laevilitorina.LocationSouthern Ocean.TaxonLittorinidae, Laevilitorininae, Laevilitorina.MethodsUsing 750 specimens from 16 Southern Ocean Laevilitorina populations across >8000 km, we analysed mitochondrial COI and nuclear 28S sequences to uncover the evolutionary history of these marine near‐shore snails. We utilized multi‐locus phylogenetic reconstructions, species‐delimitation analyses, divergence‐time estimations and geometric morphometrics.ResultsMolecular data revealed that the widespread nominal species L. caliginosa comprises seven species‐level clades, all supported by morphological data, whereas the Antarctic nominal species L. antarctica, L. claviformis and L. umbilicata are conspecific. Six “caliginosa” clades are restricted to southern South America, but one lineage extends from Antarctica to distant sub‐Antarctic islands on both sides of the APF. Geometric morphometrics also identified significant differences among these clades, but uncoupled from genetic differentiation.Main conclusionsThe apparent trans‐APF distribution of the poorly dispersing Laevilitorina caliginosa is largely illusory: this taxon consists of at least seven discrete species, only one of which has a trans‐APF distribution. Similar to most Laevilitorina species, the remaining six “caliginosa” clades are narrow endemics. Biogeographical patterns in Laevilitorina reflect the role of vicariance associated with geological processes together with recent long‐distance dispersal events. Laevilitorina originated near the Eocene/Oligocene boundary and diversified during the Miocene and the Pliocene. Laevilitorina is not a cryptic‐species complex: speciation was accompanied by hitherto unrecognized morphological differentiation. This study represents the most detailed molecular work on Southern‐Ocean littorinids and reveals unforeseen diversity across this globally important region.

Cryptostylis species (Orchidaceae) from a broad geographic and habitat range associate with a phylogenetically narrow lineage of Tulasnellaceae fungi

While many Australian terrestrial orchids have highly specialized mycorrhizal associations, we tested the hypothesis that the geographically widespread orchid genus Cryptostylis associates with a diversity of fungal species. Using fungal isolation and molecular approaches, we investigated the mycorrhizal associations of five Australian Cryptostylis species (27 sites sampled) and included limited sampling from three Asiatic Cryptostylis species (two sites). Like related orchid genera, Tulasnellaceae formed the main fungal associations of the Cryptostylis species we sampled, although some ectomycorrhizal, ericoid and saprotrophic fungi were detected infrequently. Each species of Australian Cryptostylis associated with three to seven Tulasnella Operational Taxonomic Units (OTUs), except for C. hunteriana where only one Tulasnella OTU was detected. In total, eleven Tulasnella OTUs associated with Australian Cryptostylis. The Asiatic Cryptostylis associated with four different Tulasnella OTUs belonging to the same lineage as the Australian species. While five Tulasnella OTUs (T. australiensis, T. prima, T. warcupii, T. densa, and T. punctata) were used by multiple species of Australian Cryptostylis, the most commonly used OTU differed between orchid species. The association with different Tulasnella fungi by Cryptostylis species co-occurring at the same site suggests that in any given environmental condition, Cryptostylis species may intrinsically favour different fungal OTUs.

Vertical distribution of Pseudo-nitzschia in the Gulf of Naples across the seasons

Pseudo-nitzschia is a widespread genus of marine pennate diatoms comprising 58 species of which 28 can produce the neurotoxin domoic acid, causative of Amnesic Shellfish Poisoning (ASP). Species of the genus are found in both oceanic and coastal waters where they can form large blooms. The timing and magnitude of blooms is generally described based on water samples collected at the surface, while limited information is available on cell distribution within the water column. To address this knowledge gap, we investigated the vertical (0-50 m) distribution of Pseudo-nitzschia species identified in light microscopy using weekly samples collected in the Gulf of Naples (Italy) across an annual cycle (April 2006-April 2007). Physical variables and nutrient concentrations were also monitored. The genus is primarily abundant in surface waters, where spring blooms of P. cf. delicatissima and two morphotypes of P. galaxiae were related to the presence of a water layer with low salinity and high concentration of inorganic nutrients. Blooms of P. cf. pseudodelicatissima, P. allochrona and P. multistriata were recorded at surface during the summer-early autumn, when the water column was stratified and nutrient concentrations were low. Our observations confirmed the marked seasonality of Pseudo-nitzschia species described at our study site with light microscopy and molecular approaches, with species virtually absent from surface waters for long periods of the year. However, the high quantitative resolution applied in this study allowed to reveal low concentrations of Pseudo-nitzschia species/species complexes throughout the water column over the year. Since Pseudo-nitzschia do not produce benthic resting stages, their presence in deeper waters suggests that these species rely on rare overwintering cells that can function as bloom inocula.

First record of the genus Acletoxenus (Diptera: Drosophilidae) and its predaceous species A. formosus (Leow, 1864) in Egypt, with some field observations and biological remarks

BackgroundThe genus Acletoxenus (tribe Gitonini, subfamily Steganinae, family Drosophilidae) is a small widespread genus, comprising only four species worldwide, namely: Acletoxenus indicus Malloch, 1929, A. quadristriatus Duda, 1936, A. meijerei Duda, 1924 in addition to A. formosus (Leow, 1864), the species of the present study. The larvae of Acletoxenus spp. are known as predators of whiteflies.ResultsThe genus Acletoxenus and its predaceous species A. formosus (Leow, 1864) are recorded in the present study for the first time from Egypt. This species was found associated with the immature stages of the glasshouse whitefly, Trialeurodes vaporariorum Westwood, 1856 (Hemiptera: Aleyrodidae) feeding on the castor bean plant, Ricinus communis L. which has been grown at the Plant Protection Institute, Agricultural Research Center, Giza, Egypt. The morphological diagnoses, in situ predatory behavior in the field and ex situ biological remarks in the laboratory were discussed.ConclusionThe predaceous drosophilid fly, Acletoxenus formosus (Leow, 1864), is recorded herein with its genus for the first time from Egypt as the second representative of the tribe Gitonini (subfamilies Steganinae, family Drosophilidae) in the country. The recording of this species in Egypt is of a great interest as it will encourage and lead to further research on different biological aspects. This drosophilid is a beneficial fly as its larvae are predators of immature stages of whiteflies (family Aleyrodidae) and it could be used as a potential biological control agent.

Ten new species of Memecylon (Melastomataceae) from Madagascar

Stone, R.D. (2022). Ten new species of Memecylon (Melastomataceae) from Madagascar. Candollea 77: 81–103. In English, English and French abstracts. Memecylon L. (Melastomataceae, Olisbeoideae) is a widespread paleotropical genus of forest shrubs and small trees, and is one of the ten most species-rich genera of woody plants in Madagascar. All of the Malagasy species are endemic to the island, and most of them are known from just one or two sites. As part of ongoing work towards a comprehensive taxonomic revision, ten new Malagasy species are described and illustrated here: M. arenicola R.D. Stone, M. conjugens R.D. Stone, M. draconopterum R.D. Stone, M. fissuricola R.D. Stone, M. insolitum R.D. Stone, M. linearifolium R.D. Stone, M. longipes R.D. Stone, M. majus R.D. Stone, M. ourantherum R.D. Stone, and M. ultramaficum R.D. Stone. The conservation status of each species is provisionally assessed in accordance with the IUCN Red List Categories and Criteria. Received on July 26, 2021. Accepted on February 2, 2022. First published online on June 1, 2022.

New syarinid pseudoscorpions from Ecuador (Pseudoscorpiones, Syarinidae: Ideobisium and Ideoblothrus)

The pseudoscorpion (Arachnida: Pseudoscorpiones) fauna of mainland Ecuador, excluding the Galápagos Islands, is poorly known, with only 41 described species in 9 families. The family Syarinidae has a pantropical distribution and presently comprises ca 120 species in 17 valid genera that are found in leaf litter and subterranean habitats, mostly in tropical and subtropical climates. Four syarinid species have been recorded from Ecuador, including the Galápagos, in two widespread genera, Ideobisium and Ideoblothrus, but field collections suggest that these pseudoscorpions are common and abundant in all forest systems across the country. Here, we review field collections of syarinids from mainland Ecuador and describe five new species in these genera: Ideobisium kichwa sp. nov. (Napo Province, Colonso Chalupas Natural Reserve), I. sonqo sp. nov. (Napo Province, Colonso Chalupas Natural Reserve), I. susanae sp. nov. (Napo Province, Jatun Sacha Natural Reserve), Ideoblothrus nadineae sp. nov. (Napo Province, Colonso Chalupas Natural Reserve) and I. safinai sp. nov. (Pichincha Province, Otongachi Natural Reserve) based on morphology. These species seem to have narrow distributions and we therefore restrict the ranges of two species previously recorded from Ecuador (Ideobisium crassimanum Balzan, 1892 and Ideoblothrus costaricensis (Beier, 1931)) to their countries of origin, which is Costa Rica and Venezuela, respectively.

First molecular phylogeny and species delimitation of West PalaearcticPollenia(Diptera: Polleniidae)

AbstractCluster flies of the genus Pollenia are known as mass invaders of human dwellings, but are important plant pollinators in the temperate climatic zone. Despite being the most species-rich and widespread genus in Polleniidae, no study to date has tested infrageneric relationships using molecular data. Here we use three molecular markers, COI, Ef-1α and CAD to reconstruct the phylogenetic relationships between 18 West Palaearctic species of Pollenia, representing eight predefined morphological species groups, using both maximum likelihood and Bayesian approaches. We show several instances where morphological and molecular results are congruent, but also instances where they are discordant. We develop a COI barcode reference library for 18 species, containing newly generated data (87 sequences) and sequences retrieved from the Barcode of Life Data System (BOLD). We analyse this dataset using both Automatic Barcode Gap Discovery (ABGD) and Bayesian Phylogenetics & Phylogeography (BPP) methods to validate morphological species hypotheses and delimit species. The results of these species delimitation analyses were, in most cases, identical and aligned with predefined morphological species concepts. Based on the results of our analyses, we synonymize P. moravica (stat. rev.) with P. amentaria and assign 191 unidentified sequences from BOLD to named morphospecies.

The First Cbk-Like Phage Infecting Erythrobacter, Representing a Novel Siphoviral Genus

Erythrobacter is an important and widespread bacterial genus in the ocean. However, our knowledge about their phages is still rare. Here, a novel lytic phage vB_EliS-L02, infecting Erythrobacter litoralis DSM 8509, was isolated and purified from Sanggou Bay seawater, China. Morphological observation revealed that the phage belonged to Cbk-like siphovirus, with a long prolate head and a long tail. The host range test showed that phage vB_EliS-L02 could only infect a few strains of Erythrobacter, demonstrating its potential narrow-host range. The genome size of vB_EliS-L02 was 150,063 bp with a G+C content of 59.43%, encoding 231 putative open reading frames (ORFs), but only 47 were predicted to be functional domains. Fourteen auxiliary metabolic genes were identified, including phoH that may confer vB_EliS-L02 the advantage of regulating phosphate uptake and metabolism under a phosphate-limiting condition. Genomic and phylogenetic analyses indicated that vB_EliS-L02 was most closely related to the genus Lacusarxvirus with low similarity (shared genes < 30%, and average nucleotide sequence identity < 70%), distantly from other reported phages, and could be grouped into a novel viral genus cluster, in this study as Eliscbkvirus. Meanwhile, the genus Eliscbkvirus and Lacusarxvirus stand out from other siphoviral genera and could represent a novel subfamily within Siphoviridae, named Dolichocephalovirinae-II. Being a representative of an understudied viral group with manifold adaptations to the host, phage vB_EliS-L02 could improve our understanding of the virus–host interactions and provide reference information for viral metagenomic analysis in the ocean.

Khaya revisited: Genetic markers and morphological analysis reveal six species in the widespread taxon K. anthotheca

AbstractKhaya (Meliaceae) is a widespread genus of trees distributed from the tropical forests of Africa to Madagascar and the Comoros. Khaya species are very close morphologically and some contain considerable phenotypic and ecological diversity, raising the question of their delimitation: this is the case of Khaya anthotheca s.l. (sensu lato, including K. nyasica), which is often lumped with K. grandifoliola and K. ivorensis. We tested species delimitation within K. anthotheca by combining population‐genetic and morphological data. First, a visual inspection of over a thousand specimens suggested the existence of five morphogroups. Second, after genotyping 498 samples at 71 nuclear SNPs, Bayesian clustering analyses (STRUCTURE) first identified five genetic clusters (K1–K5), while further analyses subdivided K5 into two clusters. The six genetic clusters obtained are distributed in parapatry or allopatry from West Africa to East Africa, except for cluster K4, which is in sympatry with K3 in Central Africa. The partitioning of genetic clusters is also largely congruent with the morphogroups identified. The morphological differentiation of these clusters was confirmed by statistical analyses of 27 leaf characters. The clear‐cut genetic differentiation between clusters, with few admixed genotypes even in contact zones, argues for the recognition of distinct species following the biological species concept. Our analyses highlight that the current taxonomic treatment of Khaya underestimates by one‐half the total number of species. We identify two new species, circumscribe K. anthotheca and support the rehabilitation at the rank of species of three taxa considered to be synonyms of K. anthotheca (K. agboensis, K. euryphylla, K. nyasica). These results illustrate the strength of combining population‐genetic and morphological data to delineate an African rainforest tree species complex.

Modeling the growth and sporulation dynamics of the macroalga &amp;lt;i&amp;gt;Ulva&amp;lt;/i&amp;gt; in mixed-age populations in cultivation and the formation of green tides

Abstract. Ulva is a widespread green algal genus with important ecological roles and promising potential as a seagriculture crop. One of the major challenges when cultivating Ulva is sudden biomass disappearance, likely caused by uncontrolled and unpredicted massive sporulation. However, the dynamics of this process are still poorly understood. In this study, we propose a mathematical model describing the biomass accumulation and degradation of Ulva, considering the potential impact of sporulation inhibitors. We developed a differential equation model describing the time evolution of Ulva biomass. Our model simulates biomass in compartments of different Ulva “age” classes, with varying growth and sporulation rates. Coupled with these classes is a differential equation describing the presence of a sporulation inhibitor, produced and secreted by the algae. Our model mimics observed Ulva dynamics. We present Ulva's biomass accumulation under different initial algae population, age distributions and sporulation rates. Furthermore, we simulate water replacement, effectively depleting the sporulation inhibitor, and examine its effects on Ulva's biomass accumulation. The model developed in this work is the first step towards understanding the dynamics of Ulva growth and degradation. Future work refining and expanding our results should prove beneficial to the ecological research and industrial growth of Ulva.

New species of Vetuprostomis from mid-Cretaceous amber of northern Myanmar (Coleoptera: Tenebrionoidea: Prostomidae).

Two new species of the prostomid genus Vetuprostomis Engel Grimaldi (Coleoptera: Tenebrionoidea: Prostomidae), V. angularis Li Cai sp. nov. and V. gaoi Li Cai sp. nov., are described from the mid-Cretaceous Burmese amber. Vetuprostomis is suggested to be more closely related to extant Dryocora Pascoe distributed in Australia and New Zealand, rather than the widespread genus Prostomis Latreille. A key to prostomid genera, as well as species in genus Vetuprostomis, is provided.

Phylogenetic conservatism of mycoparasitism and its contribution to pathogen antagonism.

Closely related species are expected to have similar functional traits due to shared ancestry and phylogenetic inertia. However, few tests of this hypothesis are available for plant-associated fungal symbionts. Fungal leaf endophytes occur in all land plants and can protect their host plant from disease by a variety of mechanisms, including by parasitizing pathogens (e.g., mycoparasitism). Here, we tested whether phylogenetic relatedness among species of Cladosporium, a widespread genus that includes mycoparasitic species, predicts the effect of this endophyte on the severity of leaf rust disease. First, we used congruence among different marker sequences (i.e., genealogical concordance phylogenetic species recognition criterion) to delimit species of Cladosporium. Next, in a controlled experiment, we quantified both mycoparasitism and disease modification for the selected Cladosporium species. We identified 17species of Cladosporium; all the species reduced rust disease severity in our experiment. Cladosporium phylogeny was a significant predictor of mycoparasitism. However, we did not observe a phylogenetic effect on disease severity overall, indicating that other mechanism/s operating independently of shared ancestry also contributed to endophyte effects on disease severity. Indeed, a second experiment showed that Cladosporium endophyte exudates (no live organism) from divergent species groups equally reduced disease severity. Our results reveal that multiple mechanisms contribute to the protective effects of an endophyte against a plant pathogen, but not all traits underlying these mechanisms are phylogenetically conserved.

Variable social organization among tuco-tucos (genusCtenomys) in theopimusclade

AbstractComparative studies of closely related species provide a powerful means of identifying the ecological and demographic factors associated with variation in mammalian social systems. Although most members of the subterranean rodent genus Ctenomys are thought to be solitary, the highland tuco-tuco (C. opimus) is group living, meaning that multiple adults share a burrow system and underground nest site. These animals are part of the opimus clade, a monophyletic collection of four named species that occur in northwestern Argentina and adjacent portions of Chile and Bolivia. As a first step toward generating a comparative assessment of social organization within this clade, we characterized spatial relationships among members of a population of Ctenomys at Antofagasta de la Sierra, Catamarca Province, Argentina. Based on geographic location and natural history, these animals were expected to be part of the opimus clade; analyses of mitochondrial cytochrome-b sequences from our study population confirmed this general phylogenetic placement. Radiotelemetry data indicated that the animals at Antofagasta were group living, with up to three adult females and one adult male sharing a burrow system. In contrast to other group-living ctenomyids, however, individuals did not consistently share nest sites. Comparisons of these data with re-analyses of spatial relationships among members of the population of C. opimus studied by O’Brien et al. (2020) revealed several intriguing differences in social organization, potential explanations for which include short-term responses to variable demographic and ecological conditions as well as more enduring responses to differences in local selective pressures. Further comparative analyses of these populations and, more generally, members of this subclade of Ctenomys will help to elucidate the factors contributing to variation in social behavior within this speciose and geographically widespread genus.

Bayesian and parsimony phylogeny of Augochlora bees (Hymenoptera: Apoidea) based on morphology: insights for their biogeography and natural history

AugochloraSmith, with 127 valid species, is the most widespread genus of Augochlorini bees, ranging from Argentina to southern Canada, including the Caribbean islands. The genus is divided into three subgenera,Augochloras. str.,OxystoglossellaEickwort, and the fossilElectraugochloraEngel. The extant subgenera were traditionally diagnosed by their nesting substrate, social behavior and morphology. However, accumulating evidence suggests that these features are not reliable for their separation, especially with the discovery of an enigmatic species sharing characteristics from both subgenera. Our objective is to provide a phylogenetic hypothesis to evaluate the monophyly of the extant subgenera and to place a new species, Augochlora (Augochlora) intermedia sp. nov. For this purpose, we compiled 110 unordered characters for 40 species ofAugochloraplus seven outgroup species and analyzed under parsimony and Bayesian inference. Topologies were very similar under both frameworks, allowing us to consistently characterize a few major lineages. Our results demonstrate that the extant subgenera correspond to monophyletic groups and the new species is sister group to remainingAugochloras. str. species. Both subgenera are widespread in the Western Hemisphere, with species groups differing in range and distributional patterns. Our interpretation is thatAugochloraarose in South America, subsequently colonizing Mesoamerica, the Caribbean and North America several times. Facultative social behavior can be found in both subgenera and in most lineages, indicating that the exclusive solitary behavior found inAugochlora purais an exception. Based on morphological clues we interpret that the habit of nesting out of the soil arose once inAugochloras. str.

Two extraordinary troglobitic species of Allokoenenia (Eukoeneniidae: Palpigradi) from Brazil: first records of this initially monotypic genus more than a century after its description

The diversity of Palpigradi is not evenly distributed among its different branches. The widespread genus Eukoenenia includes 80% of the species, while the other genera are poorly known. Allokoenenia certainly is the most understudied genus because it is represented only by the African species Allokoenenia afra Silvestri, 1913. Its description is short and does not include many features depicted in modern taxonomy of Palpigradi. In this paper, we describe two troglobitic species of Allokoenenia, report the occurrence of a third species represented by an immature specimen from Brazilian caves, and provide brief notes on the morphology of A. afra. Allokoenenia canhembora sp. nov., A. stygia sp. nov., and Allokoenenia sp. differ from A. afra by several morphological features, including more elongated appendages and a greater number of blades on lateral organs. Thus, they are considered troglomorphic. These new species are vulnerable to extinction because they are endemic to a single or few caves directly impacted by mining activities and groundwater exploitation. This study represents the first step for the conservation of these species and their habitats, since Brazilian caves with rare troglobites cannot be irreversibly impacted. Also, it brings important contributions on the distribution and morphology of this enigmatic genus.