Across complex landscapes, genetic structure can arise through a combination of geographic, ecological and historical processes. In mountain systems, isolation by distance (IBD), environment (IBE) and resistance (IBR) represent three such mechanisms but are often difficult to distinguish. The Great Dividing Range (GDR) of eastern Australia provides an ideal system for evaluating their relative contributions because of its varying elevation and climatic gradients. Here, we investigate the drivers of genetic structure in the Swamp Tigertail (Synthemis eustalacta) using an integrative framework combining population genomics, demographic analysis, morphology and ecological data. Results showed overall low genetic differentiation and no evidence for discrete population structure. Linear mixed-effects model provided no support for IBD but instead showed IBE and IBR, in which any observed genetic differentiation was correlated with environmental gradients, particularly precipitation and temperature extremes, vegetative cover and landscape resistance. Morphological analyses revealed minimal variation among sampled sites, but several traits were sexually dimorphic, suggesting potential sex-biased dispersal. Demographic reconstructions reveal long-term population stability, with paleoniche models displaying shifts in suitable habitat during past climatic oscillations. Together, these results highlight ecological and topographic isolation as key mechanisms shaping genetic variation in S. eustalacta and that montane dragonfly populations may maintain gene flow through climate cycles by tracking suitable conditions across elevational gradients rather than persisting in long-isolated refugia.

Phylogeny offers a powerful framework for understanding mechanisms driving community assembly. Yet, most empirical studies in community phylogenetics rely on observational approaches. In this study, we explore how two important drivers of community assembly-habitat size and predator presence-shape species richness and phylogenetic relatedness of prey communities by altering colonization and extinction processes. Using bromeliad invertebrate communities as our study system, we combined surveys of natural communities with experiments that manipulated habitat size and predator presence. Colonization and extinction were isolated in separate experiments to test whether effects of habitat size and predator presence differed across stages of community assembly. Following species-area theory, we expected larger habitats to increase species richness and, given the strong consumptive effects of the top predator (a damselfly larvae), we expected species richness to decline in the presence of predators. Under a community phylogenetics framework, if traits mediating responses to these factors are phylogenetically conserved, we expected the phylogenetic structure of the community (i.e., relatedness) to have deterministic patterns along both gradients. Specifically, if habitat size functions as an environmental filter, small bromeliads would host phylogenetically clustered assemblages; alternatively, if it functions as a mediator for coexistence among close relatives, larger habitats would exhibit greater relatedness. Likewise, we expected the generalist top predators to increase relatedness when closely related taxa have shared defensive traits. As traits mediating community assembly may vary in their phylogenetic distribution across lineages, we also anticipated relatedness patterns to vary across taxonomic scales. We found a positive effect of habitat size on species richness, which was driven by colonization mechanisms. Habitat size also affected relatedness, but the direction depended on the taxonomic scale, with positive relationships at broad scales and negative relationships at narrower scales. By contrast, predators reduced species richness through extinction mechanisms, although these effects were masked in natural communities by continuous replacement of individuals through colonization. Predator effects on relatedness were variable across taxonomic scales, suggesting the involvement of multiple traits at different phylogenetic depths. Together, our findings highlight the complex interplay between environmental factors and community assembly in structuring taxonomic and phylogenetic dimensions of diversity.

Abstract Webspinners (Insecta: Embioptera) are an unusual insect order that are known for their subsocial behavior and prolific silk-production. Due to their unique foreleg silk glands, and spider-like ability to produce silk throughout their entire life cycle, webspinners are hypothesized to have evolved silk independently from other arthropod lineages. To date, there are no reference-quality genomes available for the order, preventing the study of their silk gene origination and diversification. Here, we assembled PacBio HiFi reference genomes and characterized the silk genes present in two webspinner species, Aposthonia ceylonica and Oligotoma nigra . The genomes reveal multiple full-length copies of the primary Embioptera silk gene , e-fibroin, that have undergone both ancestral and recent gene duplications within the group. For both species, all e-fibroin paralogs show the presence of complex repeat units consisting of multiple exons and introns that are remarkably homogenized across each gene. We also used μ CT-scanning of the internal silk glands to provide details concerning the localization of silk production in foreleg tarsi, and interspecific morphology. Article summary This study introduces the first high-quality genomes for webspinners, enabling new research on silk for evolutionary biologists and materials scientists alike. The authors sequenced two embiopteran species, Aposthonia ceylonica and Oligotoma nigra , to compare silk genes and gland structure using micro-computed tomography, an imaging method that shows internal anatomy in detail. They found multiple copies of the primary silk gene in both species that likely arose from multiple duplication events at different evolutionary times. These silk genes exhibit unusual gene structure with hierarchically organized repeat units that are highly homogenized within a gene. The findings show that silk genes have a complex evolutionary history in webspinners and provide a foundation for studying silk diversity within the order, and in the broader context of insect silk.

Insect wings possess morphological adaptations that have been selected for efficient flight aerodynamics. In odonates, the pterostigma is a structure located toward the distal leading edge of the wing. While the pterostigma is relatively understudied regarding its role in dragonfly flight dynamics, it is hypothesized to contribute mass toward the leading edge of the wing to provide stability, increase critical flying speed, and reduce the possibility of wing damage during prolonged and high-speed flight. Dragonflies can be categorized into 2 broad types of flight behavior: perchers, which spend most of their time perched on vegetation, and flyers, which spend much of their time in flight. Because perchers and flyers vary in flight demands, we hypothesized that there may be differences in the structural characteristics of the pterostigma that correlate with the 2 flight modes. To assess morphological differences of the pterostigma between perchers and flyers, we measured surface area, length, and mass characteristics of the fore- and hindwing pterostigma. We found that perchers had larger and heavier fore- and hindwing pterostigma than flyers, despite having lighter bodies and wings. We suggest that a larger pterostigma in perchers may be associated with the need for greater wing torque during rapid, maneuverable flight.

Panbiogeography has long been controversial due to its general rejection of both active dispersal as a key step that may lead directly to speciation, and the role of natural selection in evolution. As vicariance is the only means of speciation allowed within panbiogeography, montane taxa are assumed to have arrived at elevation through “passive uplift”. With one species found in high elevations of Kā Tiritiri-o-te-Moana (the Southern Alps) in Aotearoa (New Zealand), and another at lowland elevations, Kapokapowai dragonflies (genus Uropetala, family Petaluridae) are an excellent system for evaluating the hypothesis of passive uplift, and thus for evaluating the underlying assumptions of panbiogeography. Recent research on Kapokapowai, which employed demographic modelling from a reference genome assembly and assessment of population structure with sampling across the range of Kapokapowai dragonflies, strongly supports active colonization over passive uplift, showing evidence for a dynamic dispersal history with multiple active shifts between high and low elevations. Two subsequent publications have misrepresented this research and cited Kapokapowai as evidence that passive uplift is the primary means by which species come to inhabit alpine habitats. This is not supported by available data. Furthermore, under passive uplift, alpine Kapokapowai would have had to persist on Kā Tiritiri-o-te-Moana through multiple periods of glaciation, requiring persistence in a habitat in which, to our knowledge, no Petaluridae larvae have yet been observed. While vicariance can certainly result in speciation, the case of Kapokapowai dragonflies clearly demonstrates that the failure to consider dispersal can lead to an incomplete understanding of evolutionary histories.

Dragonflies and damselflies (Insecta: Odonata) are descended from what were most likely the first winged animals, which flew ~320 million years ago (Ma). They comprise ~6400 extant species distributed across all continents except Antarctica. Examination of long-standing hypotheses regarding the role of flight behavior and wing morphology in shaping the global distribution of odonates has been limited by spatial and taxonomic scope. Here, we leverage mobilized trait and distribution data derived from specimens and literature combined with a uniquely comprehensive target-enriched phylogeny (~940 loci) covering all families and 67% of recognized genera. Ancestral state reconstruction of flight behavior strategies ("flyer" vs. "percher") suggests the odonate ancestor was a flyer, spending a majority of its time when active on the wing, with multiple independent transitions to percher. Several transitions back to the flyer behavior have also occurred. Aspect ratios for forewings and hindwings showed a strong relationship between these traits and perching and flying behavioral strategies. Divergence time estimation suggests the crown age of Odonata to be 290-325 Ma. Bayesian biogeographical evolutionary analysis of nine biogeographical realms provides a preliminary biogeographical history for odonates spanning 325 Ma. Key family-level splits occurred during the Jurassic and Cretaceous, paralleling the increasing isolation of landmasses and the poleward drift of the contemporary Australasian and Holarctic regions. Both behavioral and morphological adaptations likely facilitated the distributional success of select odonate lineages. This study lays the foundation for a revised classification of odonates and a more complete understanding of the influence of flight behavior and wing morphology in relation to evolutionary processes shaping past and current odonate diversity.

We present an updated classification for extant dragonflies and damselflies (Odonata) and summarize new insights gained over the past two decades. Our focus is on taxa of family-level and higher and we indicate subfamilies only when their monophyly is currently undisputed and well-supported by phylogenetic analyses. The superfamily Calopterygoidea was known to be polyphyletic and based on recent phylogenomic data is divided into nine superfamilies, of which eight are recognized for the first time (Amphipterygoidea stat. nov., Euphaeoidea stat. nov., Megapodagrionoidea stat. nov., Mesopodagrionoidea stat. nov., Philogangoidea stat. nov., Polythoroidea stat. nov., Priscagrionoidea stat. nov., Tatocnemidoidea stat. nov.). At present, midway through 2025, odonates are divided into three suborders, 17 superfamilies, 55 families and 687 genera containing 6447 species (May 1, 2025). We give an overview of the distribution of the families across major biogeographical realms. Except for Amanipodagrionidae, nymphs of at least some of the species of all families are known. Our understanding of the classification of dragonflies and damselflies has greatly improved in the past two decades largely due to phylogenetic inferences based on molecular studies. We expect that in the next few years the last remaining issues regarding the higher-level phylogeny and classification, including the position of the South American genus Sciotropis and the division into subfamilies of families such as Coenagrionidae, Aeshnidae, Gomphidae and Libellulidae, will be better refined by the acquisition of additional morphological and genomic data.

The anisopteran Neocordulia Selys, 1882 is the most species-rich genus among all Corduliidae s.l. in the Neotropical region, and its taxonomy is plagued with inconsistencies, misconceptions and weak species-level hypotheses. This is mostly due to the boost in the number of species described since the most recent revision in the 1990s. Many species are known only from a single specimen that emerged in laboratory conditions, reared from larvae, and many are pending revision. This genus is a key group for understanding the phylogeny and spatial and morphological evolution of Corduliidae s.l. as part of Idomacromiidae, a clade including four other genera: Idomacromia Karsch, 1896, Nesocordulia McLachlan, 1882, Oxygastra Selys, 1870 and Syncordulia Selys, 1882. Neocordulia mambucabensis Costa & T.C. Santos, 2000, a Brazilian Atlantic Forest endemic dragonfly, is one of the poorly known species of the genus. The morphology and taxonomic status of adults and larvae of this South American emerald are reviewed based on the study of specimens from the southernmost known population for this species and compared to the type series. Illustrations, including images from the types, collection and alive specimens, as well as details of its habitat are provided. The male is rediagnosed, while our results do not support the female “allotype” as belonging to N. mambucabensis, so it is redescribed based on unequivocal specimens. The morphology of ultimate stadium larvae (F-0) is described, diagnosed, and illustrated for the first time. Because of numerous inaccuracies in literature, resulting in deficient knowledge of the taxonomy of Neocordulia, the genus requires further revision. Based on the information currently available, it is not possible to definitively provide adequate diagnoses for Neocordulia species.

Scientific and public interest in the global status of insects has surged recently; however, understanding the relative importance of different stressors and their interconnections remains a crucial problem. We use a meta-synthetic approach to integrate recent hypotheses about insect stressors and responses into a network containing 3385 edges and 108 nodes. The network is highly interconnected, with agricultural intensification most often identified as a root cause. Habitat-related variables are highly connected and appear to be underdiscussed relative to other stressors. We also identify biases and gaps in the recent literature, especially those generated from a focus on economically important and other popular insects, especially pollinators, at the expense of non-pollinating and less charismatic insects. In addition to serving as a case study for how meta-synthesis can map a conceptual landscape, our results identify many important gaps where future meta-analyses will offer critical insights into understanding and mitigating insect biodiversity loss.

Stoneflies (Insecta: Plecoptera) are a widespread group of freshwater insects known for their ecological significance and sensitivity to environmental change. This diverse order encompasses over 4,000 species across 17 families, with the number of described species predicted to increase substantially over the coming years. This review surveys the past and present landscape of stonefly systematics, emphasizing recent advancements in our understanding of the phylogenetic relationships within this group to the ordinal, subordinal, and family level. We highlight the need for expanded biodiversity surveys, particularly in underexplored regions such as high-elevation ecosystems, the Southern Hemisphere, and the Arctic, and identify the key challenges impeding the advancement of systematic research, in particular the decline in taxonomic expertise. Looking forward, we outline a vision for the future of stonefly systematic research, advocating for increased inclusivity, collaborative research efforts, and the integration of advanced molecular methodologies.

The antennae and mouthparts of treehoppers in twelve genera (11 Membracidae, and 1 Aetalionidae) were examined to identify and describe the fine structure of the antennae and the mouthparts. The gross morphology of the antennae and mouthparts are similar to that of other previously studied Auchenorrhyncha groups. Six types of sensilla were observed on the setiform antennae: trichodea I (str), trichodea III (str III), basiconica I (sb I), basiconica II (sb II), sensilla chaetica (sch) and peg-like sensilla coeloconica (psc). The trichodea and chaetica sensilla were primarily distributed in the scape and pedicel. Peg-like sensilla coeloconica were located only on the flagellum and were found inside cuticular depressions. The antennal scape is characterized by a densely sculptured area. In the labrum, two non-sensory protuberances were identified: acanthae, and scale-like projections. The labium was primarily covered by sensilla trichodea I (str) and III (str III), and sensilla basiconica (sb I) and II (sb II); tooth-like projections were present at the apex of the labium. Mandibular stylets contained small barbs. More taxa and additional ecological information are needed to determine the adaptative value of the structures identified here.

Communities working in entomology, ecology, and other natural sciences are known for having shortfalls in racial and gender diversity. We aim to uncover drivers of this diversity gap. To achieve this, we distributed a survey to undergraduate students at large academic institutions in North America. The survey was designed to profile the perspectives people had about entomology, ecology, and agricultural science compared to other disciplines, and to see if these perspectives differed among demographics (race, gender, and sexual orientation). In addition to soliciting information about general perception relevant to recruitment and retention (approachability, hospitality/how welcoming a field is, fear, importance, interest, job availability), we also asked targeted questions about race-related issues (race motivated violence, racist authority figures, historical racism). In general, we found that race and sexual orientation did not often explain differences in perception of academic fields while gender did. Entomology was perceived the most negatively compared to all other disciplines, largely being driven by a high perception of fear, lack of knowledge about the importance of entomology, and the perception that jobs are lacking in the field. However, LGBTQ+ status predicted a significant increase in the perception of entomology as a "beautiful" science. Perception of race-related issues in ecology and biology differed by demographic, but the effect-size was small. We present several recommendations for higher education based on our results.

The Neotropical tribe Darnini (Hemiptera: Membracidae) includes approximately 102 species classified in 18 genera. Darnini displays marked morphological heterogeneity among its genera, and the tribe has been poorly studied compared with other treehopper groups. The tribe has been considered monophyletic due to the presence of cucullate setae on the ventral sides of the femora. A previous morphology-based analysis placed the genera of Darnini into three groups that differ in pronotal shape, suggesting that the common ancestor of each group acquired a different defensive strategy, mimicking either bird droppings, thorns, or raindrops. To test this hypothesis, we compiled the most taxon- and character-rich dataset for Darnini and related groups to date, using anchored hybrid enrichment to obtain data for 492 genetic loci comprising >133,855 nucleotide positions for a total of 51 taxa (31 Darnini species, 11 representatives of other tribes of Darninae and 9 taxa representing other subfamilies). Phylogenetic analysis of the concatenated nucleotide sequence data using Maximum Likelihood and coalescent gene tree (ASTRAL) analyses yielded similar topologies, with most branches having maximum support. The results are consistent with the hypothesis of a single acquisition of each of the three defensive pronotal syndromes early in the evolution of Darnini, but also indicate that two genera of the tribe Hemikypthini (Hemikyptha and Atypa) are derived within the 'thorny' and 'raindrop' groups of Darnini, consistent with their pronotal shapes. This indicates that Hemikypthini is polyphyletic and that the characters of the leg chaetotaxy used to diagnose both tribes are homoplasious. Therefore, we treat Darnini and Hemikypthini as synonyms.

Hawai'i's pinapinao (Megalagrion McLachlan) comprises a radiation of 23 endemic damselfly species within Coenagrionidae. Despite being a unique study system for understanding geology's impacts on evolutionary processes among Odonata, the understanding of these damselflies' temporal, geographic and phylogenetic origins remains incomplete. Testing macroevolutionary hypotheses has been hampered by conflicting topologies. To resolve these uncertainties, we performed phylogenetic analyses including divergence time estimation with 90 nuclear loci (>50 kbp) and 2 mitochondrial loci (>1 kbp), sampling representatives from 37 genera within core Coenagrionidae and 90% of Megalagrion species, including multiple island populations. We used ancestral range estimations, diversification analyses, agent-based simulation modelling and ancestral state reconstruction to infer the group's origin and biogeography and assess traits' roles in diversification. Our findings indicate Megalagrion's ancestor diverged from core Coenagrionidae in the early Eocene (similar to 51 MA) and diversified in the early Miocene (similar to 19 MA), suggesting Megalagrion's MRCA predates Kaua'i's emergence by 7-21 MY. Diversification analyses suggest a low rate after Megalagrion diverged from Coenagrionidae followed by a sudden increase around 19 MA, and simulation modelling supports extinction playing a significant role. Extant Megalagrion diversity is largely explained by ecological diversification into at least five clades with distinct breeding habitats that likely evolved on Northwestern Hawaiian Islands that are now-sunken seamounts. Speciation continued as descendants dispersed to current Hawaiian Islands as islands emerged. Species breeding in seeps further diversified within the island of Kaua'i. Our results highlight including geologic changes over time in evolutionary studies and increase understanding of diversification patterns, biogeography and adaptive radiation on islands.

Neurocordulia, commonly called shadowdragons, are crepuscular dragonflies, flying mainly at dusk. The genus comprises seven species, which occur across the eastern part of Canada and the United States. Here, we used targeted enrichment probes to sequence ~1000 loci for all specimens of each species, allowing for the first phylogenetic assessment of the genus. Additionally, we collected individuals of N. yamaskanensis from a population in Ontario, Canada, and used whole genome resequencing to estimate population structure. Beyond broadly reconstructing the phylogeny of Neurocordulia, we provided a comprehensive bibliography review of past research on the genus, a key to the species, and distribution models for each species.

BackgroundHuman alteration of natural environments and habitats is a major driver of species decline. However, a handful of species thrive in human altered environments. The biology, distribution, population structure, and molecular adaptations enabling certain species to thrive in human-altered habitats are not well understood. Here, we evaluate the population and functional genomics, ecological niche and distributions, and geometric morphometrics of the blue dasher (Pachydiplax longipennis), one of the most ubiquitously observed insects in human altered habitats.ResultsUsing resequencing data we identify a number of genes involved with the success of the blue dasher in human altered habitats, including loci contributing to immune function and response to oxidative stress. Some genes related to these functions are found in regions of strong population structure, while others are not, potentially indicating both regional and widespread adaptations to urban environments within this species. Using one of the most robust locality datasets for any species to date, we also generate habitat suitability predictions which show that P. longipennis has spread with urbanization, suggesting humans have created suitable habitat for this species. These results complement morphological and genomic data showing P. longipennis (particularly East of the Rocky Mountains) has the capacity to rapidly disperse to newly suitable habitats.ConclusionsWe confirm that P. longipennis is well equipped to deal with the stress of urban habitats, by observing large swaths of suitable habitat of P. longipennis throughout its range, both within and outside of major cities and towns, and identifying conserved and population specific molecular mechanisms related to urban stress. Furthermore, we observe minor variability in suitable habitat of P. longipennis throughout the years; we do not note any substantial loss or gain in habitat, suggesting its resiliency to fluctuations in temperature and precipitation throughout the United States. Given the shared barriers to colonizing an urban habitat, we expect that many of the molecular adaptations to urban environments we have identified in P. longipennis could be found in other animals that are broadly tied to urban habitats.

Insects are declining in abundance and species richness, globally. This has broad implications for the ecology of our planet, many of which we are only beginning to understand. Comprehensive, large-scale efforts are urgently needed to quantify and mitigate insect biodiversity loss. Because there is broad interest in this topic from a range of scientists, policymakers, and the general public, we posit that such endeavors will be most effective with precise and standardized terms. The Entomological Society of America is the world's largest association of professional entomologists and is ideally positioned to lead the way on this front. We provide here a glossary of definitions for biodiversity loss terminology. This can be used to enhance and clarify communication among entomologists and others with an interest in addressing the multiple overlapping research, policy, and outreach challenges surrounding this urgent issue.

Biodiversity monitoring is crucial for detecting species declines and informing conservation efforts; however, traditional field-based surveys are constrained by time, resources, and geographic scale. Ecological Niche Modeling (ENM) provides an alternative using large citizen-science datasets but requires validation against empirical data. Here, we compare field-collected and ENM-derived estimates of species richness for dragonfly (Odonata: Anisoptera) species across southeastern Australia, assessing concordance and strength of each approach. We conducted field surveys at 42 localities across New South Wales and Victoria, collecting 476 individuals representing six families, 18 genera, and 33 species. Using occurrence records from GBIF, we generated a stacked richness map, derived from individual species ENMs. While modeled richness predominantly overestimated richness at field sites, we observed two instances of oversampling in field data, where richness exceeded model predictions. Field-based richness exhibited no significant relationships with elevation, latitude, or longitude, most likely due to limited sampling effort and spatial coverage. In contrast, ENM-based richness declined significantly with elevation and increased with latitude and longitude. However, rank-based correlations found significant associations between field-based and ENM-based richness estimations, suggesting broadscale patterns can still be estimated from field data. Our data highlights the complementary value of field surveys and ENM, in which broadscale richness gradients can be identified, while also capturing local-scale variation and validation of predictions.

The striped emeralds (Somatochlora Selys) are a Holarctic group of medium-sized metallic green dragonflies that mainly inhabit bogs and seepages, alpine streams, lakes, channels and lowland brooks. With 42 species they are the most diverse genus within Corduliidae (Odonata: Anisoptera). Systematic, taxonomic and biogeographic resolution within Somatochlora remains unclear, with numerous hypotheses of relatedness based on wing veins, male claspers (epiproct and paraprocts) and nymphs. Furthermore, Somatochlora borisi was recently described as a new genus (Corduliochlora) based on 17 morphological characters, but its position with respect to Somatochlora is unclear. We present a phylogenetic reconstruction of Somatochlora using Anchored Hybrid Enrichment (AHE) sequences of 40/42 Somatochlora species (including Corduliochlora borisi). Our data recover the monophyly of Somatochlora, with C. borisi recovered as sister to the remaining Somatochlora. We also recover three highly supported clades and one of mixed support; this lack of resolution is most likely due to incomplete lineage sorting, third-codon position saturation based on iterative analyses run on variations of our dataset and hybridization. Furthermore, we constructed a dataset for all species based on 20 morphological characters from the literature which were used to evaluate phylogenetic groups recovered with molecular data; the data support the validity of Corduliochlora as a genus distinct from Somatochlora. Finally, divergence time estimation and biogeographic analysis indicate Somatochlora originated in the Western North Hemisphere during the Miocene, with three dispersal events to the Eastern North Hemisphere (11, 7 and 5 Ma, respectively) across the Beringian Land Bridge.