Long-term population persistence of flightless weevils (Eurhoptus pyriformis) across old- and second-growth forests patches in southern Appalachia

Molecular diversity of Pseudoscorpiones in southern High Appalachian leaf litter

The Pseudoscorpiones fauna of North America is diverse, but in regions like the southern Appalachian Mountains, they are still poorly documented with respect to their species diversity, distributions and ecology. Several families have been reported from these mountains and neighbouring areas. Here we analyse barcoding data of 136 specimens collected in leaf litter, most of them from high-elevation coniferous forest. We used ASAP as a species delimitation method to obtain an estimation of the number of species present in the region. For this and based on interspecific genetic distance values previously reported in Pseudoscorpions, we considered three different genetic Kimura two-parameter distance thresholds (3%/5%/8%), to produce more or less conservative estimates. These distance thresholds resulted in 64/47/27 distinct potential species representing the families Chthoniidae (33/22/12 species) and Neobisiidae (31/25/15) and at least six different genera within them. The diversity pattern seems to be affected by the Asheville Depression, a major biogeographic barrier in this area, with a higher diversity to the west of this geographic feature, particularly within the family Neobisiidae. The absence of representatives from other families amongst our studied samples may be explained by differences in their ecological requirements and occupation of different microhabitats.

A Review of Forest Management Effects on Terrestrial Leaf Litter Inhabiting Arthropods

Leaf litter arthropods are some of the most abundant and diverse communities in forests and provide myriad ecosystem services from decomposition and mineralization to pollination and predation. They are important to forest health and management and, in turn, are affected by how we manage our forests. Various forest management techniques such as clear cutting, burning, and chemical control of invasive species all have differing effects on ground dwelling arthropods and, despite their importance, a review of the literature on these effects does not currently exist. My objective with this paper is to review the effects of different types of forest management on arthropods in leaf litter systems.

Two Divergent Genetic Lineages within the Horned Passalus Beetle, Odontotaenius disjunctus (Coleoptera: Passalidae): An Emerging Model for Insect Behavior, Physiology, and Microbiome Research

The horned passalus (Odontotaenius disjunctus) is one of the most extensively studied saproxylic beetles in the eastern United States. For several decades this species has been the subject of investigations into the behaviors associated with subsociality as well as physiological responses to stress, and, most recently, the composition of its gut microbiome has been closely examined. However, no published study to date has characterized this beetle's broad-scale population genetic structure. Here, we conducted intensive geographic sampling throughout the southern Appalachian Mountains and surrounding areas and then assessed mitochondrial DNA (mtDNA) sequence variation among individuals. Unexpectedly, we discovered two divergent, yet broadly sympatric, mtDNA clades. Indeed, the magnitude of divergence between- vs. within-clades ranged from 5.9 to 7.5×, depending on the dataset under consideration, and members of the two lineages were often syntopic (i.e., found in the same rotting log). Given the potential implications for past and future studies on behavior, physiology, and the gut microbiome, we developed a simple cost-efficient molecular assay (i.e., polymerase chain reaction restriction fragment length polymorphism; PCR-RFLP) to rapidly determine mtDNA clade membership of O. disjunctus individuals. We suggest that the evolutionary processes that gave rise to the emergence and persistence of divergent sympatric lineages reported here warrant investigation, as this type of spatial-genetic pattern appears to be rare among southern Appalachian forest invertebrates.

The role of glacial-interglacial climate change in shaping the genetic structure of eastern subterranean termites in the southern Appalachian Mountains, USA

The eastern subterranean termite, Reticulitermes flavipes, currently inhabits previously glaciated regions of the northeastern U.S., as well as the unglaciated southern Appalachian Mountains and surrounding areas. We hypothesized that Pleistocene climatic fluctuations have influenced the distribution of R. flavipes, and thus the evolutionary history of the species. We estimated contemporary and historical geographic distributions of R. flavipes by constructing Species Distribution Models (SDM). We also inferred the evolutionary and demographic history of the species using mitochondrial (cytochrome oxidase I and II) and nuclear (endo-beta-1,4-glucanase) DNA sequence data. To do this, genetic populations were delineated using Bayesian spatial-genetic clustering, competing hypotheses about population divergence were assessed using approximate Bayesian computation (ABC), and changes in population size were estimated using Bayesian skyline plots. SDMs identified areas in the north with suitable habitat during the transition from the Last Interglacial to the Last Glacial Maximum, as well as an expanding distribution from the mid-Holocene to the present. Genetic analyses identified three geographically cohesive populations, corresponding with northern, central, and southern portions of the study region. Based on ABC analyses, divergence between the Northern and Southern populations was the oldest, estimated to have occurred 64.80 thousand years ago (kya), which corresponds with the timing of available habitat in the north. The Central and Northern populations diverged in the mid-Holocene, 8.63 kya, after which the Central population continued to expand. Accordingly, phylogeographic patterns of R. flavipes in the southern Appalachians appear to have been strongly influenced by glacial-interglacial climate change.

OPEN RESEARCH BADGES

This article has been awarded Open Materials, Open Data Badges. All materials and data are publicly accessible via the Open Science Framework at https://doi.org/10.5061/dryad.5hr7f31.

A revision of the genus Eurhoptus LeConte, 1876 (Curculionidae, Cryptorhynchinae) of America north of Mexico

The genus Eurhoptus LeConte, 1876 is revised for America north of Mexico. Eight species are recognized including E.pyriformis LeConte, 1876, E.sordidus (LeConte, 1876), E.curtus (Hamilton, 1893), resurrected name, and five new species as follows: E.rileyi new species (type locality, Texas, Hidalgo County, Bentsen Rio Grande State Park), E.imbricatus new species (type locality, Texas, Bandera County, Lost Maples State Natural Area), E.cariniventris new species (type locality, Texas, Bandera County, Lost Maples State Natural Area), E.occidentalis new species (type locality, Texas, Brewster County, Big Bend National Park), and E.aenigmaticus new species (type locality, Alabama, Winston County, Bankhead National Forest). Descriptions or redescriptions, and images of taxonomically important structures are presented for all species. A key to the eight species is included.