The hide, larder, and carpet beetles (Coleoptera: Dermestidae) are a family of mainly scavenger beetles, with numerous species such as the khapra beetle (Trogoderma granarium Everts, 1898), the black carpet beetle [Attagenus unicolor (Brahm, 1791)] and the hide beetle (Dermestes maculatus De Geer, 1774) being widely recognized as serious economic pests of stored products and museum collections. A stable classification and reliable identification of genera and species of these pests and their 1,700 relatives are of great relevance for trade restrictions, biosecurity, pest management, forensics, and biodiversity surveys. In this study, we examined and sequenced mitochondrial genomes of 477 dermestid specimens, representing all subfamilies and 90% of the globally recognized tribes and subtribes. Our study provides the most comprehensive, taxonomically verified, and vouchered resource of mitochondrial reference sequences linked to specimen images and occurrence records of pests and their relatives, enabling eDNA surveys, metabarcoding and molecular species identification. It also reconstructs the phylogeny of Dermestidae based on molecular and morphological data for the first time, thereby providing robust phylogenetic hypotheses for a stable classification system from family to genus-level. Accordingly, a revised classification of Dermestidae with formal nomenclatural changes is proposed, recognizing six subfamilies: Orphilinae, Trinodinae, Trogoparvinae subfam. nov. (type genus Trogoparvus Háva, 2001), Dermestinae, Attageninae, and Megatominae. Trinodinae is recovered towards the base of Dermestidae with three tribes: Trinodini (=Trinoparvini syn. nov.), Thylodriini, and Trichelodini. Dermestinae is the only subfamily with adults lacking a median ocellus, and it includes the tribes Thorictini stat. nov. (that is downgraded from Thorictinae), Marioutini, and Dermestini. The endemic Australian genus Derbyana Lawrence and Ślipiński was recovered within Holarctic Dermestes Linnaeus. Attageninae is strongly supported and includes the monogeneric Adelaidiini and polygenic Attagenini. Former subgenera of Attagenus Latreille, i.e., Lanorus Mulsant and Rey (= Paranovelsis Casey syn. nov.), Telopes Redtenbacher and Aethriostoma Motschulsky, are elevated to generic level. The largest clade, Megatominae, is confirmed as monophyletic and is divided into three tribes: Anthrenini, Ctesiini, and Megatomini. Megatomini is divided into three subtribes: Megatomina, Orphinina subtribe nov. (type genus Orphinus Motschulsky), and Trogodermina. Within the economically important lineage Trogodermina, Trogoderma Latreille is delimited to contain only Holarctic species including the Khapra beetle T. granarium Everts, while a Southern Hemisphere clade is here recognized as Eurhopalus Solier in Gay, 1849 (= Anthrenocerus Arrow, 1915; Myrmeanthrenus Armstrong, 1945; Neoanthrenus Armstrong, 1941; Sodaliatoma Háva, 2013; Reesa Beal, 1967 syn. nov.). A revised classification of the extant genera of Dermestidae is also provided.

Flight loss is a common feature of upland insect assemblages, with recent studies detecting parallel wing reduction events across independent alpine lineages. However, the geographic scale over which such repeated evolution can operate remains unclear. In this study, we use genotyping-by-sequencing to assess the genomic relationships among vestigial-winged and full-winged populations of the widespread New Zealand stonefly Nesoperla fulvescens, to test for repeated wing loss events over small spatial scales. Biogeographic analyses indicate that alpine wing loss in this widespread species is restricted to a single, narrow mountain range. Intriguingly, our coalescent analyses indicate that upland vestigial-winged N. fulvescens populations are not sister to one another, suggesting wings have been lost independently in disjunct populations of this species, over a <30 km scale. Our results suggest that selection against flight above the alpine treeline can drive rapid and repeated adaptation even across narrow spatial scales. We propose that such repetitive processes may represent a far more pervasive feature of alpine insect adaptation than is currently recognized.

Southeast Asia is a hotspot of karst systems in the tropics and many relictual taxa have been documented in caves across the region. The ancient, relictual scorpion family Pseudochactidae Gromov 1998 has a disjunct distribution and includes two hypogean subfamilies from caves in the Khammouan-Phong Nha-K Bàng Karst in the northern Annamite (Trưng Sơn) Mountains of Laos and Vietnam, and one epigean subfamily from Central Asia. A recent revision identified six species in the family; however, how these taxa dispersed and diversified into Southeast Asian cave systems has not been tested. In the present contribution, the phylogeny of Pseudochactidae is reconstructed using three mitochondrial and three nuclear markers and 140 morphological characters, divergence time and ancestral range estimation analyses are conducted, and the evolution of troglomorphic characters is investigated. Results confirm a previous hypothesis that Pseudochactidae originated in Eurasia, most likely near the Tajik block in the Carboniferous, supporting the ‘Out of Eurasia’ hypothesis and contradicting the ‘Eurogondwana’ and ‘Out of India’ hypotheses for the origin of Southeast Asian scorpions. Pseudochactidae dispersed across Southeast Asia after the collision of the Cimmerian continent and Indochina with Eurasia in the Late Jurassic. Colonization of Southeast Asian caves began in the Late Cretaceous and was completed by the Miocene. The onset of aridification in Southeast Asia during the Late Miocene resulted in the extinction of epigean Pseudochactidae, whereas hypogean members of the family likely survived within caves in the limestone massifs of the Annamite Mountains, supporting the ‘Climate Relict’ hypothesis.

Geological isolation with limited gene flow can shape phenotypic diversification among different populations or species. From Luzon northward to Taiwan lies a series of isolated volcanic islands (the Taiwan–Luzon volcanic belt) where three Pachyrhynchus species [P. sarcitis (Behrens, 1887), P. nobilis (Heller, 1912) and P. semperi (Heller, 1912)] (Coleoptera: Curculionidae: Entiminae: Pachyrhynchini) are sympatrically distributed. With intraspecific color variation across different islands, these three weevil species provide a unique opportunity to study genetic divergence associated with geographic isolation and/or phenotypic differences. In this study, genome-wide single nucleotide polymorphism (SNP) data derived from ddRAD-seq was used to reconstruct the speciation history and to delimit species within each of the three species. Our results indicate all three species have ancient diversification histories in southern islands of the Taiwan–Luzon volcanic belt instead of more recent diversification histories in northern islands. Ancestral effective population size estimations also support a scenario of a series of founder colonization events from southern to northern islands in the volcanic belt. Most island populations are monophyletic, and early-divergent populations with deep genetic structures are supported statistically as distinct species. However, color variations could occur between populations with very recent diversification, indicating a fast-evolving rate in the change of coloration, possibly due to müllerian mimicry or founder effects across this region.