Advances in technology are rapidly changing the way people transmit, view, and interact with information. These advances offer new opportunities for researchers to share scientific discoveries with each other and the general public as never before. The field of revisionary biology has audiences confined to small groups of specialists, but the core task of systematic biology—documenting the endless forms of nature—is particularly well suited to capitalize on innovations in the realm of virtual, mixed and augmented reality. Interactive three-dimensional (3D) digital models of biological specimens can help bridge barriers across scientific disciplines by circumventing technical jargon, and also promise to open exciting new vistas for public engagement. Here, we explore the potential of augmented reality for communicating the discovery of new species. As a test case, we revise a radiation of Strumigenys Smith (Hymenoptera: Formicidae) miniature trap-jaw ants in Fiji. In addition to traditional revisionary elements, we present the augmented reality application ‘Insects3D’ built specifically for this study. The application runs on mobile devices and allows users to interact with X-ray microtomography-derived 3D specimen models and visualize 3D geographic distribution maps. We recognize 23 species in Fiji, including 6 new species: S. anorak n. sp., S. artemis n. sp., S. avatar n. sp., S. gunter n. sp., S. oasis n. sp., and S. parzival n. sp. This study demonstrates the potential of leveraging 3D data and technology for a more interactive systematic biology, and the need for research programs to develop robust and generalized tools to realize this potential.

As a model organism, the tobacco hornworm Manduca sexta (Linnaeus 1763) has contributed much to our knowledge of developmental processes in insects, and major developmental changes between different larval instars are generally well understood. Second and later instars of M. sexta do not produce silk, and their spinneret and accessory labial glands (=Lyonet's glands), structures thought to be key players in silk production in other lepidopterans, are highly reduced. To our knowledge, mouthparts and labial gland morphology of the silk-producing first instar have never been described. In this study, we compared the mouthpart morphology and transcriptome profile of first and later instars of M. sexta to determine whether the loss of silk production correlates with changes in the structure of the spinneret and the labial glands, and with changes in expression of silk-related genes. We found that the first instar, unlike later instars, has a typical, silk-producing spinneret with a tube-like spigot and well developed Lyonet's glands. Moreover, three known silk protein genes are highly expressed in the first instar but exhibit little to no expression in the embryo or later instars. Thus, the changes in morphology and gene expression presented here, coinciding with changes in larval behavior from silk production to saliva spreading, further our understanding of the developmental processes underlying this transition in this model organism.

Comparative phylogenetics has been largely lacking a method for reconstructing the evolution of phenotypic entities that consist of ensembles of multiple discrete traits—entire organismal anatomies or organismal body regions. In this study, we provide a new approach named PARAMO (Phylogenetic Ancestral Reconstruction of Anatomy by Mapping Ontologies) that appropriately models anatomical dependencies and uses ontology-informed amalgamation of stochastic maps to reconstruct phenotypic evolution at different levels of anatomical hierarchy including entire phenotypes. This approach provides new opportunities for tracking phenotypic radiations and evolution of organismal anatomies.

Discothyrea Roger, 1863 is a small genus of proceratiine ants with remarkable morphology and biology. However, due to cryptic lifestyle, Discothyrea are poorly represented in museum collections and their taxonomy has been severely neglected. We perform the first comprehensive revision of Discothyrea in the Afrotropical region through a combination of traditional and three-dimensional (3D) cybertaxonomy based on microtomography (micro-CT). Species diagnostics and morphological character evaluations are based on examinations of all physical specimens and virtual analyses of 3D surface models generated from micro-CT data. Additionally, we applied virtual dissections for detailed examinations of cephalic structures to establish terminology based on homology for the first time in Discothyrea. The complete datasets comprising micro-CT data, 3D surface models and videos, still images of volume renderings, and colored stacked images are available online as cybertype datasets (Hita Garcia et al. 2019, http://doi.org/10.5061/dryad.3qm4183). We define two species complexes (D. oculata and D. traegaordhi complexes) and revise the taxonomy of all species through detailed illustrated diagnostic character plates, a newly developed identification key, species descriptions, and distribution maps. In total, we recognize 20 species; of which, 15 are described as new. We also propose D. hewitti Arnold, 1916 as junior synonym of D. traegaordhi Santschi, 1914 and D. sculptior Santschi, 1913 as junior synonym of D. oculata Emery, 1901. Also, we designate a neotype for D. traegaordhi to stabilize its status and identity, and we designate a lectotype for D. oculata. The observed diversity and endemism are discussed within the context of Afrotropical biogeography and the oophagous lifestyle.

Thickened femora of insects are correlated to enlarged muscle masses and serve two basic purposes: jumping/kicking and grasping/holding. Modifications on the ventral femoral wall and the tibial flexor tendon that are possibly involved in catch mechanisms have been described in multiple insect taxa with both jumping and grasping legs. Our comparative study aims to explore the functional and structural similarities of these modification in jumping and grasping leg types from Coleoptera, Hymenoptera, Diptera, and Orthoptera with the combination of cutting edge, noninvasive imaging methods, and classical dissections techniques. Our data indicate that locking mechanisms are present in the jumping and grasping legs of insects. We describe three femoro-tibial lock types based on the location of the interacting sclerites relative to the site of origin of the tibial flexor tendon. All of the three types can be found in jumping insect legs, whereas only one type is present in grasping legs. The locking mechanism might aid in keeping the femoro-tibial joint in a flexed position for an extended period of time. Our data indicate that morphologically similar modifications in the femoro-tibial joint are involved in energy-saving mechanisms both in jumping and grasping legs in insects.

Morphology, encompassing the study of phenotypic form and function, is one of the ancient branches of human knowledge and is foundational for organismal classification. Two decades into the current century, the specialized biological knowledge of the history and pattern of evolution has been revolutionized by genome-scale sequencing technologies, and cryptic variation within and among species is quantifiable even with a few genetic markers. The application of statistical phylogenetic models of nucleotide and amino acid substitution to sequence data has enabled revised interpretations of morphological identities—be they population-level generalizations, such as species diagnoses, or the definition and homology of specific anatomical entities—and evolutionary transformation across the tree of life (e.g., insect genitalia, ancestral morphology of Polyneoptera). These models are also being adapted for phylogenetic analysis of morphological data, allowing explicit incorporation of fossil terminals and their stratigraphic information. In this special collection of research in Insect Systematics & Diversity (ISD), we present six papers on the topic of Current Techniques in Morphology .These papers span an arc from integrated methods of phenotype observation and visualization to methods and background for phylogenetic modeling of morphological characters. In this editorial, I review the central role of anatomical classification and anatomical terminology in systematic by way of outlining the special collection. I argue ultimately for a reconceptualization of phylogenetic morphology.

Heteroptera is a diverse suborder of insects that includes many plant pests, human disease vectors, and nuisance pests, but also beneficial insects. Previous analyses have supported recognition of seven monophyletic infraorders. A clade comprising Leptopodomorpha, Pentatomomorpha, and Cimicomorpha is also well-accepted, but relationships among the early-diverging lineages, including the aquatic infraorders (Nepomorpha and Gerromorpha), have remained poorly resolved and controversial. Phylogenomic analyses of 2,159 gene alignments derived from Illumina sequencing of transcriptomes were employed to explore the stability of relationships among major heteropteran lineages. These analyses included maximum likelihood analyses of amino acid and nucleotide sequences, as well as multi-species coalescent analysis and quartet sampling. All analyses favored a sister position of the Nepomorpha to the remaining Heteroptera. The placement of the Nepomorpha and other ambiguously supported nodes, including some within the Pentatomomorpha were explored with quartet sampling. Results of quartet sampling revealed only a slight majority of quartets supported the placement of the Nepomorpha, and some varying alternate topologies were supported within the Pentatomomorpha. These results highlight the instability of deep nodes that divide aquatic and other early-diverging lineages within the Heteroptera, suggesting that some relationships remain difficult to resolve even with large amounts of data. In addition, despite the large amount of transcriptome data analyzed, quartet sampling revealed considerable underlying conflict for some nodes, even where bootstrap support is high, emphasizing the importance of considering multiple clade support values when analyzing phylogenomic datasets.

The southern Appalachian Mountains in eastern North America host exceptional diversity, a substantial proportion of which has been generated in place. Yet, beyond broad generalities, bio- and phylogeographical patterns, and the temporal scale of diversification in the region are poorly resolved. Using one mitochondrial and one nuclear marker, we analyze intraspecific diversity patterns in a flightless, litter-inhabiting rove beetle Dasycerus carolinensis Horn. Our goals were to reconstruct the phylogeographical history of this species, producing a dated intraspecific phylogeny, and to examine previous hypotheses of possible cryptic divergence across populations of the species. Samples derive from a mix of old-growth fragments and secondary growth forests, and we also ask whether old-growth remnants host a larger proportion of genetic diversity in the species. We recover a strong primary subdivision among major lineages across the French Broad River basin (dated to ∼5.8 MYBP), and a secondary subdivision among western populations dating to ∼4.5 MYBP. Most interpopulation uncorrected divergences exceed 5%, strongly suggesting cryptic differentiation. Old-growth populations do not show greater genetic diversity than secondary-growth populations, indicating that most populations have persisted through recent anthropogenic disturbance.

The male genitalic characters of Hexapoda are well known for their great taxonomic and systematic value. Despite insect male genitalia displaying large diversity, variation, and modification across orders, some structures are consistently present, and such characters can serve as the basis for discussion regarding homology. In the order Lepidoptera, a male genitalic structure widely known as the ‘juxta’ is present in many taxa and absence or modification of this character can be phylogenetically informative at the generic or higher level. We here focus on the systematics of the so-called ‘Taygetis clade’ within the nymphalid subtribe Euptychiina, and report an unusual case of ‘juxta loss’ in a single species, Taygetina accacioi Nakahara & Freitas, n. sp., a new species from Brazil named and described herein. Additionally, we describe another west Amazonian Taygetina Forster, 1964 species, namely Taygetina brocki Lamas & Nakahara, n. sp., in order to better document the species diversity of Taygetina. Our most up-to-date comprehensive molecular phylogeny regarding ‘Taygetis clade’ recovered these two species as members of a monophyletic Taygetina, reinforcing the absence of juxta being a character state change occurring in a single lineage, resulting in an apomorphic condition, which we report here as a rare case in butterflies (Papilionoidea).