Search

Species in the beetle family Histeridae exhibit numerous defensive adaptations, from a generally compact and spheroid body shape to retractable tarsi, legs, heads, and antennae. Modes of antennal concealment are particularly variable, underscoring the importance of protecting these essential sensory structures. Understanding the evolution of these morphological features has been hindered by a weak understanding of the family's basal phylogeny, and corresponding patterns of niche-use and morphological evolution. Cretaceous amber fossils have been proliferating, filling in important morphological gaps right around the time of the family's explosive radiation. Here we describe 10 new species from Cretaceous Burmese ambers, six of them representing new genera: Palaeabraeus glabrus gen. nov. et sp. nov. (Abraeinae); Pseudacritus extinctus gen. nov. et sp. nov. (Abraeinae); Miculissima excavata gen. nov. et sp. nov. (unplaced to subfamily); Placatister cascus gen. nov. et sp. nov. (unplaced to subfamily); Cretomalus tibiodentatus gen. nov. et sp. nov. (Dendrophilinae: Paromalini); Prodigister tricostatus gen. nov. et sp. nov. (unplaced to subfamily); Anapleus punctulatus sp. nov. (Dendrophilinae: Anapleini); Pantostictus hirsutus sp. nov. (Abraeinae: Pantostictini); Phasmister kraliceki sp. nov. (Onthophilinae); and Phasmister planatus sp. nov. (Onthophilinae). A revised phylogenetic analysis that includes these taxa supports previous hints that inquilinous forms were prevalent and diverse during the Cretaceous. These results also support the contention that pressures in these environments to protect the critically important sensory apparatus, the antenna, were strong, driving multiple origins of two of the more protective configurations among extant taxa. Some of the new genera remain unplaced to subfamily, underscoring the gaps that still remain in the early fossil record for the family, and the continued need for more comprehensive analyses of combined data from extant taxa, along with additional extinct forms that we may assume will continue to be discovered. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Synthetic studies of arthropod systematics and biodiversity are hindered by overreliance on 'preferred' semaphoronts, those life stages (typically adult males) that provide the most taxonomically distinctive characters. However, modern sequence‐based methods for inventory have no such limitations and permit incorporation of any and all representatives of a species. Here, we briefly review the growth and potential of these approaches to faunistic and systematic studies and share results from our own recent work that illustrate the value that other morphs, immature stages and females added to these studies. [ABSTRACT FROM AUTHOR]

In the eastern United States, 74 species of Anillini in two genera have been described, with most belonging to Anillinus Casey. Until now, no systematic framework has existed for this large genus, hampering integrative studies. Using DNA sequences from 101 Nearctic species, we present a well-resolved molecular phylogeny supporting a sound systematic framework. Sixteen species groups of Appalachian Anillinus are diagnosed, in part using newly recognized variation in the number of modified male protarsi and the state of the spermathecal duct. We present the first descriptions of Nearctic anilline larvae, which possess none of the synapomorphies of previously described anilline larvae. Within Anillinus, two major clades are mostly consistent with setation of the right paramere: a "hairy clade" with more than four setae, and a "quadrisetose clade." Throughout the phylogeny, microhabitat use varies within each clade, and several endogean lineages are phylogenetically isolated. Our work increases the South Carolina fauna by nearly five-fold. Nine new species are described, Serranillus monadnock sp. nov., Anillinus castaneus sp. nov., Anillinus choestoea sp. nov., Anillinus dentatus sp. nov., Anillinus jancae sp. nov., Anillinus mica sp. nov., Anillinus micamicus sp. nov., Anillinus seneca sp. nov., and Anillinus simplex sp. nov. Several species are newly reported from South Carolina, bringing the total to 20 described species representing seven species groups. Two endemic groups inhabit deep clay soils in the Piedmont and possess unique male sexual characters. The Anillini are a unique component of Nearctic biodiversity, with great potential as a model system for studies of biogeography, secondary male sexual modification, and endogean adaptations. [ABSTRACT FROM AUTHOR]