Search for: All records

The small, eyeless beetles of the genus Anillinus Casey (Coleoptera: Carabidae: Trechinae: Anillini) comprise a diverse, ubiquitous, but poorly known component of insect biodiversity in the southeastern United States. Their limited dispersal capabilities make them ideal subjects for biogeography, but taxonomic problems and undescribed species diversity hamper such studies. In this paper, we redescribe four enigmatic species, Anillinus docwatsoni Sokolov and Carlton, Anillinus elongatus Jeannel, Anillinus pecki Giachino, and Anillinus turneri Jeannel, and consider their relationships. The elongatus species group is revised, with descriptions of four newly discovered species, Anillinus arenicollis Harden and Caterino, new species, Anillinus montrex Harden and Caterino, new species, Anillinus pittsylvanicus Harden and Caterino, new species, and Anillinus uwharrie Harden and Caterino, new species. Two species previously considered part of the elongatus group are determined to not belong here, Anillinus cavicola Sokolov and Anillinus turneri Jeannel. The exact placement of A. turneri remains uncertain, but it shares some character states with the sinuaticollis group. We erect the pecki group for A. docwatsoni and A. pecki, which are likely sister species. We provide a key to the eastern species groups of Anillinus and the species of the elongatus and pecki species groups. Anillinus pecki is broadly distributed in the southern Appalachian Mountains northeast of the French Broad River basin, while A. docwatsoni is apparently endemic to the Hickory Nut Gorge in western North Carolina. Anillinus pecki is reported for the first time from Tennessee and Virginia. All members of the elongatus group have small geographic ranges and are difficult to sample without special techniques, hinting that many more species await discovery in the densely populated Piedmont region of North Carolina, where natural habitats are rapidly being lost. Our sampling was not dense enough to test biogeographic hypotheses, but distributions of the elongatus group species suggest that hydrochory might have played an important role in passive dispersal and reproductive isolation. These taxonomic contributions will facilitate future studies on the genus and serve to highlight the rich insect biodiversity that remains to be discovered in the southeastern United States. 

Abstract The terrestrial isopod genusLigidiumincludes 58 species from Europe, Asia, and North America. In Eastern North America four species are recognized:L. floridanumandL. mucronatum, known just from their type localities in Florida and Louisiana respectively,L. blueridgensis, endemic to the southern Appalachians, andL. elrodii, widespread from Georgia to Ontario. The genus shows a marked morphological conservatism, and species are differentiated mostly by small morphological differences; it is not always easy to determine if such variability represents inter‐ or intraspecific variation. Here, we explore the diversity ofLigidiumfrom the southern Appalachian Mountains, exploring the congruence of morphologically defined groups with multilocus phylogenetic reconstructions and molecular species delimitation methods. We have studied a total of 130 specimens from 37 localities, mostly from the southern Appalachians, and analysed mtDNA (Cox1) and nuclear (28S, NaK) sequences. Morphologically, we recognized eight morphotypes, most of them assignable to current concepts ofL.elrodiiandL.blueridgensis. Phylogenetic analyses supported the evolutionary independence of all morphotypes, and suggest the existence of 8–9 species, including limited cryptic diversity. Single‐locus delimitation analyses based on mtDNA data suggest the existence of a much higher number of species than the multilocus analyses. The estimated age of the ancestors of sampled lineages indicates a long presence of the genus in eastern North America and old speciation events through the Miocene. Our results indicate a higher diversity than previously thought among theLigidiumpopulations present in the southern Appalachian Mountains, with several species to be described. 

Species of the genusLathrobiumGravenhorst (Coleoptera: Staphylinidae: Paederinae) from North America north of Mexico are reviewed and 41 species are recognized. Morphology and mitochondrial COI sequence data were used to guide species designations in three flightless lineages endemic to the southern Appalachian Mountains, a biologically diverse region known for cryptic diversity. Using a combination of phylogeny, algorithm-based species delimitation analyses, and genitalic morphology, five new cryptic species are described and possible biogeographic scenarios for their speciation hypothesized:L. balsamenseHaberski & Caterino,sp. nov.,L. camplyacraHaberski & Caterino,sp. nov.,L. islaeHaberski & Caterino,sp. nov.,L. lividumHaberski & Caterino,sp. nov.,L. smokienseHaberski & Caterino,sp. nov.Five additional species are described:L. absconditumHaberski & Caterino,sp. nov.,L. hardeniHaberski & Caterino,sp. nov.,L. lapidumHaberski & Caterino,sp. nov.,L. solumHaberski & Caterino,sp. nov., andL. thompsonorumHaberski & Caterino,sp. nov.Two species are transferred fromLathrobiumtoPseudolathraCasey:Pseudolathra parcum(LeConte, 1880),comb. nov.andPseudolathra texana(Casey, 1905),comb. nov.Twenty-six names are reduced to synonymy. Lectotypes are designated for 47 species. Larvae are described where known, and characters of possible diagnostic value are summarized. Species diagnoses, distributions, illustrations of male and female genitalia, and a key toLathrobiumspecies known from the Nearctic region (including several introduced species) are provided. 

Elevation gradients provide a wealth of habitats for a wide variety of organisms. The southern Appalachian Mountains in eastern United States are known for their high biodiversity and rates of endemism in arthropods, including in high-elevation leaf-litter taxa that are often found nowhere else on earth. Trechus Clairville (Coleoptera: Carabidae) is a genus of litter inhabitants with a near-global distribution and over 50 Appalachian species. These span two subgenera, Trechus s. str. and Microtrechus Jeannel, largely restricted to north and south of the Asheville basin, respectively. Understanding the diversification of these 3–5 mm flightless beetles through geological time can provide insights into how the litter-arthropod community has responded to historical environments, and how they may react to current and future climate change. We identified beetles morphologically and sequenced six genes to reconstruct a phylogeny of the Appalachian Trechus. We confirmed the Asheville Basin as a biogeographical barrier with a split between the north and south occurring towards the end of the Pliocene. Finer scale biogeography, including mountain-range occupancy, was not a reliable indication of relatedness, with group ranges overlapping and many instances of species-, species group-, and subgeneric sympatry. This may be because of the recent divergence between modern species and species groups. Extensive taxonomic revision of the group is required for Trechus to be useful as a bioindicator, but their high population density and speciose nature make them worth additional time and resources. 

Medon icarus Caterino, new species (Staphylinidae: Paederinae) is described, restricted largely to the highest elevations of the southern Appalachian Mountains, USA. This flightless species occurs across several high ranges in the region, and analysis of COI sequences from known populations reveals deep genetic divergences among them. Insufficient morphological differentiation has been observed to subdivide them, but the possibility remains that this represents a cryptic species complex, with from 5–12 genetically but otherwise indistinguishable members. This is the only member of this mainly western Nearctic and Palearctic genus in the southeastern US, though it appears to be closely related to the northeastern winged species Medon americanus Casey. Description of DNA-associated larval specimens, along with adult morphological and molecular information, will help determine its position among global Medonina diversity. 

Dipara trilineata (Diparidae) is a widespread eastern North American parasitoid with apterous females and winged males. Despite its seemingly limited dispersal capabilities, phylogeographic analysis over southern Appalachia reveals little structure, with only limited population level isolation. DNA barcoding surveys also definitively associate the male of the species, which had previously been misattributed, and a description of the correctly associated male is provided. 

HorologionValentine, one of the rarest and most enigmatic carabid beetle genera in the world, was until now known only from the holotype ofHorologion speokoitesValentine, discovered in 1931 in a small cave in West Virginia. A single specimen of a new species from Virginia was collected in 1991, but overlooked until 2018. DNA sequence data from specimens of this new species,Horologion hubbardisp. nov., collected in 2022 and 2023, as well as a critical examination of the external morphology of both species, allow us to confidently placeHorologionin the supertribe Trechitae, within a clade containing Bembidarenini and Trechini. A more specific placement as sister to the Gondwanan Bembidarenini is supported by DNA sequence data. Previous hypotheses placingHorologionin or near the tribes Anillini, Tachyini, Trechini, Patrobini, and Psydrini are rejected. The existence of two species ofHorologionon opposite sides of the high mountains of the middle Appalachians suggests that these mountains are where the ancestralHorologionpopulations dispersed from, and predicts the discovery of additional populations and species. All specimens ofH. hubbardiwere collected in or near drip pools, and most were found dead, suggesting that the terrestrial epikarst, rather than caves, is the true habitat ofHorologion, which explains their extreme rarity since epikarst has not been directly sampled. We recognize the tribe Horologionini, a relict lineage without any close relatives known in the Northern Hemisphere, and an important part of Appalachian biodiversity. 

Abstract We are far from knowing all species living on the planet. Understanding biodiversity is demanding and requires time and expertise. Most groups are understudied given problems of identifying and delimiting species. DNA barcoding emerged to overcome some of the difficulties in identifying species. Its limitations derive from incomplete taxonomic knowledge and the lack of comprehensive DNA barcode libraries for so many taxonomic groups. Here, we evaluate how useful barcoding is for identifying arthropods from highly diverse leaf litter communities in the southern Appalachian Mountains (USA). We used 3 reference databases and several automated classification methods on a data set including several arthropod groups. Acari, Araneae, Collembola, Coleoptera, Diptera, and Hymenoptera were well represented, showing different performances across methods and databases. Spiders performed the best, with correct identification rates to species and genus levels of ~50% across databases. Springtails performed poorly, no barcodes were identified to species or genus. Other groups showed poor to mediocre performance, from around 3% (mites) to 20% (beetles) correctly identified barcodes to species, but also with some false identifications. In general, BOLD-based identification offered the best identification results but, in all cases except spiders, performance is poor, with less than a fifth of specimens correctly identified to genus or species. Our results indicate that the soil arthropod fauna is still insufficiently documented, with many species unrepresented in DNA barcode libraries. More effort toward integrative taxonomic characterization is needed to complete our reference libraries before we can rely on DNA barcoding as a universally applicable identification method. 

We describe a second species of Nearctomeris Wesener, 2012, a genus of pill millipede endemic to the southern Appalachians, based on morphological and molecular evidence. The fauna of Glomerida in America is characterized by its low diversity, and Nearctomeris smoky sp. nov. is only the fifth species of the order known from the eastern United States. Our phylogenetic analyses based on COI sequences recover a tentatively monophyletic lineage including both eastern American genera Onomeris Cook, 1896 and Nearctomeris , with a common ancestor in the Late Cretaceous to Mid Eocene and extant diversity within genera dating back to the Miocene. Our results suggest that the observed low diversity of the group in the eastern US is likely caused by extinction events, but it is also possible that new species are yet to be found. We provide new records for Nearctomeris inexpectata Wesener, 2012, Onomeris underwoodi Cook, 1896 and O. australora Hoffman, 1950; the latter is here reported for the first time from South Carolina. We also present DNA barcoding data for all species of Glomerida present in the US that are not yet publicly available. 

Thirteen new species of Euconnus Thomson (Staphylinidae: Scydmaeninae: Glandulariini) are described from the southern Appalachian Mts, USA: Euconnus megalops sp. nov. , E. vexillus sp. nov. , E. cumberlandus sp. nov. , E. vetustus sp. nov. , E. adversus sp. nov. , E. astrus sp. nov. , E. cultellus sp. nov. , E. falcatus sp. nov. , E. cataloochee sp. nov. , E. kilmeri sp. nov. , E. draco sp. nov. , E. tusquitee sp. nov. , and E. attritus sp. nov. These share a number of morphological characters with the Old World subgenus Cladoconnus Reitter, representing a diversification of species distinct from anything previously known from the western hemisphere. Most of the species occur at higher elevations, some at the tops of the region’s highest mountains, and a few are single-peak endemics. No females of these species are winged, and in several species neither sex is winged. A preliminary phylogeny suggests the wingless species represent a clade within a clade of wing-dimorphic species.