Abstract European Lepidoptera have been subject of dense sampling for their DNA barcodes because of several active regional DNA barcoding initiatives. This intensive barcoding has revealed many cases of unexpected patterns of diversity in mitochondrial COI (Cytochrome c oxidase subunit 1) barcode region of several Lepidoptera. In this study, we generated high-throughput target enrichment data for intra-alpine populations of 4 lepidopteran species, which were known to show extraordinary but unexplained variability in their barcodes. We then compared the patterns observed from genomic data to those known from the barcodes using phylogenomics, population genetics, and species delimitation tools. Based on our findings, we revised the taxonomy of one of the studied species, ie, Symmoca signella (Hübner, 1796) species-complex with 2 new species descriptions. In the case of other 3 species—Aricia nicias, Orenaia alpestralis, and Setina aurita, we did not find clear evidence for separating intra-alpine populations into distinct species and instead found varying levels of within-species divergence between the populations. We show that the DNA barcodes alone do not always reflect the genetic structure of populations or species in an accurate manner and demonstrate the usefulness of genomic approaches for a robust delimitation of species.

Abstract Insects exhibit remarkable morphological extremes, including elongate appendages and prominent outgrowths. However, exaggerated morphologies in insects are exceptionally rare in the fossil record, leaving their origins and functional significance largely unexplored. Here, we describe a new short-winged flower beetle (Kateretidae) from mid-Cretaceous amber (ca. 99 Ma), Protokateretes ensifer Zhao, Engel & Cai, sp. nov., characterized by an extremely elongate and highly modified antennal scape in males, a striking morphological specialization unparalleled in extant insects. Our morphological disparity analysis demonstrates the diagnostic reliability of the scape for species differentiation and provides evidence of surprising negative allometry in antennal scape size. We show that the exaggerated scape likely functioned as claspers for male positioning on females or as a female receptor-interacting signal. Abundant aggregations of Asteropollis pollen grains preserved with Protokateretes ensifer suggest a putatively beetle-mediated pollination of chloranthaceous angiosperms during late Mesozoic. Together with previous findings of Cretaceous kateretids and their associated angiosperm hosts, our discovery highlights that diverse flowering plant lineages were likely pollinated by beetles during the mid-Cretaceous angiosperm radiation. This study sheds light on the functional significance of exaggerated morphological traits and illuminates possible early beetle-angiosperm coevolution that predates the dominance of butterflies and bees.

Abstract We describe 2 new genera and 6 new species of unusual armored scale insects (Hemiptera: Coccomorpha: Diaspididae) from Chile: Austraspis Normark, Normark and Amouroux, gen. n.; Aysenaspis Normark, Normark and Amouroux, gen. n.; Austraspis foye Normark, Normark and Amouroux, sp. n.; Austraspis llanquihue Normark, Normark and Amouroux, sp. n.; Austraspis pehuen Normark, Normark and Amouroux, sp. n.; Austraspis relicta Normark, Normark and Amouroux, sp. n.; Aysenaspis michay Normark, Normark and Amouroux, sp. n.; and Anotaspis paradisi Normark, Normark and Amouroux, sp. n. Austraspis is remarkable for having abdominal segments V and VI free (not fused), with only segments VII and VIII fused to form the pygidium, and in having a proliferation of multilobulate lobes (each with 3 to 6 lobules) on the abdomen. Aysenaspis is remarkable for having all 8 abdominal segments free and in having ducts that are 8-shaped at the internal end. Phylogenetic analysis of part of 28S rRNA places the 2 new genera (Austraspis and Aysenaspis) outside of currently recognized subfamilies of Diaspididae and corroborates the placement of Anotaspis in Ancepaspidinae. We place the new genera in the heretofore monotypic taxon Xanthophthalminae Ferris, revived subfamily. We provide a revised key to the subfamilies of Diaspididae and global keys to all the species of Xanthophthalminae and Ancepaspidinae. The host plants of Austraspis are Araucaria araucana (Araucariaceae) and Drimys winteri (Winteraceae), which both have undergone little morphological change since the Mesozoic. Austraspis may also retain a relatively ancient morphology; its pygidial appendages are relatively undifferentiated compared to those of other diaspidids.

Abstract Limacodidae (Zygaenoidea), a mostly pantropical family of 1,800+ species, is known for sluglike caterpillars with suckers below rather than typical prolegs. They typically have either venomous spines (nettles) or a smooth surface (gelatines) above. Previous limacodid phylogenies were of limited geographic scope or narrow taxonomic focus, thus unable to show the family’s internal relationships comprehensively. Our phylogenetic hypotheses include 95 genera and 125 species of Limacodidae (stat. nov.) of worldwide distribution, doubling genera, and tripling species numbers represented from previous studies. Additionally, 14 species in other zygaenoid families and 6 outside Zygaenoidea are included. In contrast to other works based on independent analysis of either molecular or morphological data, our limacodid-focused trees are the first ones to combine molecular data with morphological characters from adults and immature stages. Resulting topologies are based on 1 mitochondrial and 6 nuclear genes, totaling 5,153 base pairs, and 122 morphological characters (5,275 characters in total). Our trees support the monophyly of Zygaenoidea and a new subfamily arrangement of a monophyletic Limacodidae: Crothaeminae (stat. rev.), Dalcerinae (stat. nov.), Chrysopolominae, and Limacodinae (stat. nov.). Two tribes recognized in Limacodinae, and previous subfamilies in Dalceridae and Chrysopolomidae are reduced to tribal rank. Synapomorphies of all life-stage characters are presented for Limacodidae and other family groups of Zygaenoidea. The total evidence topology is congruent with many features of egg, larval, and adult stage evolution. With new larval ontogenetic information, we present a hypothesis on how ontogeny and other modifications played a significant role in Limacodidae diversification through various defensive strategies.

Abstract The twisted-wing parasites (Strepsiptera Kirby) are among the most obscure and enigmatic orders in the Insecta. Strepsipterans are endoparasites of 7 insect orders, and have developed complex specialized life histories accordingly. The number of described strepsipteran species is relatively small for an insect order (fewer than 650, with 43 currently known only from fossils), they have very unusual ecological, morphological, and genetic characteristics, and little is known about their host use. Equally convoluted is the history of their systematics, which has featured contention about their phylogenetic position in the insect radiation—a dispute termed “the Strepsiptera Problem.” Within the order, relationships between lineages have been largely resolved with the advent of molecular data. However, limited availability of genetic data and specimen inaccessibility have restricted progress in the field. The fact that many species are described only from singular male specimens poses the biggest challenge to the resolution of strepsipteran phylogenetic relationships. In this review, we give a comprehensive background on the biology and taxonomy of this order, discuss the history of strepsipteran systematics, detail the current challenges of its study, and propose future action for its resolution.

Abstract The hoverflies are one of the most abundant families in Diptera and an important category of resource insects. They can provide important ecosystem services such as pollination and beneficial biological control agents. In the four-subfamily classification system of the Syrphidae, the monophyly of the Eristalinae within Syrphidae has not been recovered. In this study, we performed new sequencing and analysis of low-coverage whole genomes for 25 species of Syrphidae. Phylogenetic reconstructions were conducted based on different datasets and analytical strategies. Across all our analyses, the monophyly of the Syrphinae is supported but we do not recover the monophyly of the Eristalinae, consistent with previous research findings. Additionally, employing fossil calibrations for divergence time estimation, our results indicate that the origin of the Syrphidae occurred between the Albian and Aptian stages, approximately between 120.5 and 109.3 million years ago, the origin of the subfamily Syrphinae was dated in the Early Eocene, about 50.8–47.8 million years ago, in accordance with the diversification of their prey. This study will help us understand the higher-level phylogenetic and evolutionary relationships within Syrphidae.

Abstract The first fossil rust fly (Diptera: Psilidae) from the Insect Bed of the Bembridge Marls of the Isle of Wight is also the first known fossil record of the subfamily Chylizinae. It is late Eocene: Priabonian in age, 34.2 Ma. Chyliza colenutti Ross, Zhou, Hoffeins & Crighton, sp. nov. is compared with 30 extant species of Chyliza and differs from them in having a relatively long 2nd basal cell compared to the discal cell. Some other fossil Acalyptratae records are reviewed and their probable ages updated. The phylogenetic position of the Psilidae is currently uncertain so the family may have appeared anytime from 70–40 million years ago.

Abstract Crescent butterflies of the Phyciodes tharos group have a long-standing reputation for taxonomic difficulty. We assessed species boundaries in the P. tharos group using genome-wide single-nucleotide polymorphism (SNP) data, focusing on sampling in western Canada, where 4 species (P. tharos, P. cocyta, P. batesii, and P. pulchella) have classically been recognized. Phylogenetic and cluster-based analyses confirm that there are indeed 4 species based on the maintenance of genomic integrity in the presence of occasional hybridization and low levels of gene flow. Mitochondrial cytochrome c oxidase I (COI) does not consistently distinguish species, with haplotypes extensively shared between species. Limited sampling of P. batesii indicates complex boundaries and interactions with other Phyciodes, especially with P. pulchella and P. cocyta. This study demonstrates the power of a genome-wide perspective to elucidate the integrity of boundaries between recently diverged species that remain capable of occasional hybridization.

Abstract Classification of the biological diversity on Earth is foundational to all areas of research within the natural sciences. Reliable biological nomenclatural and taxonomic systems facilitate efficient access to information about organisms and their names over time. However, broadly sharing, accessing, delivering, and updating these resources remains a persistent problem. This barrier has been acknowledged by the biodiversity data sharing community, yet concrete efforts to standardize and continually update taxonomic names in a sustainable way remain limited. High diversity groups such as arthropods are especially challenging as available specimen data per number of species is substantially lower than vertebrate or plant groups. The Terrestrial Parasite Tracker Thematic Collections Network project developed a workflow for gathering expert-verified taxonomic names across all available sources, aligning those sources, and publishing a single resource that provides a model for future endeavors to standardize digital specimen identification data. The process involved gathering expert-verified nomenclature lists representing the full taxonomic scope of terrestrial arthropod parasites, documenting issues experienced, and finding potential solutions for reconciliation of taxonomic resources against large data publishers. Although discordance between our expert resources and the Global Biodiversity Information Facility are relatively low, the impact across all taxa affects thousands of names that correspond to hundreds of thousands of specimen records. Here, we demonstrate a mechanism for the delivery and continued maintenance of these taxonomic resources, while highlighting the current state of taxon name curation for biodiversity data sharing.