ABSTRACT Body size is an important component of burying beetle (genus Nicrophorus) life history, affecting competitive interactions and resource use. Currently, there is no comprehensive analysis of what drives these differences in size and how body size is distributed within the genus and across its geographic range. We used a large dataset of body size measurements and geographical data to evaluate the relative importance of phylogeny, biogeography, and ecology in explaining body size variation in burying beetles. Mean body size distribution among species is broad (4.15–10.97 mm pronotal width) and skewed, with more small and medium‐bodied species than large species. We found evidence of phylogenetic signal in the evolution of body size across the genus, although only one instance of sister species both being giants and no instances of sister species being both small. However, the phylogenetic analysis does not explain the evolution of extremes in Nicrophorus body size. Areas with higher species richness have a greater spread between the largest and smallest species, and body size is divergent between most sister species and more strongly so between sympatric sister species, even after correcting for phylogeny. We found evidence of rapid initial divergence in body size following speciation, which increased over time in sympatric species, but stabilized in non‐sympatric species. Smallest body sizes and highest species richness are concentrated in northern hemisphere temperate latitudes. Taken together, these results suggest character displacement by body size may be a significant factor allowing coexistence of burying beetle species; however, other mechanisms of niche partitioning are likely important contributors to coexistence. High species richness in temperate, mesic areas of the northern hemisphere may be driven by habitat and climatic suitability. We encourage further experimentation to test our proposed mechanisms of body size divergence and geographic distribution in Nicrophorus.

Abstract With 67 species, Orthetrum Newman is the most speciose genus within the family Libellulidae Leach (Odonata: Anisoptera), distributed across the Afrotropical, Palearctic, Indo‐Malayan, Malagasy, Oceania, Wallacea and Australasian regions. Despite its wide distribution, serving as a top predator in freshwater ecosystems, the evolutionary history of Orthetrum has remained unresolved, with prior studies limited to morphology and sparse genetic sampling (<33% of species). We present here the most comprehensive phylogenetic study of Orthetrum to date, sampling 50 of 67 species (~75%) using Anchored Hybrid Enrichment (AHE). Our analyses, integrating concatenated maximum likelihood and coalescent‐based approaches, provide a robust, strongly supported phylogeny that confirms the monophyly of Orthetrum and reveals four distinct clades. Two clades comprise mostly Afrotropical species, whereas the remaining clades are from the Palearctic, Indo‐Malayan, Oceania, Wallacea and Australasian regions. Divergence time estimates indicate that Orthetrum originated ~32 million years ago, with major diversification occurring from ~28 Ma onward, well after major continental fragmentation events. Ancestral range reconstruction under the best supported Dispersal–Extinction–Cladogenesis (DEC) framework does not support a single‐region origin; instead, early lineages are inferred to have occupied a broadly connected Afro–Eurasian system. Subsequent diversification is characterized by stepwise dispersal across adjacent regions, including repeated expansions into the Indo‐Malayan and Palearctic regions, followed by colonization of Australasia, Wallacea and Oceania. The Afrotropical region emerges as a major centre of lineage persistence and diversification, with subsequent range expansion in some lineages during the early Miocene (~23 Ma), whereas Madagascar reflects at least five independent colonization events from Africa resulting in endemic species.

An expedition in 2024 to 'Eau Island in the Kingdom of Tonga led to the collection of several female Teinobasis fatakula Marinov & Donnelly, 2013. Teinobasis fatakula is endemic to 'Eua and can only be found inhabiting a single river in the 'Eua National Park. Here we describe the female of this unique damselfly and expand its range.

A new species of Pseudagrion red-group, Pseudagrion yalomi sp. n., is described from northeastern New Britain, Papua New Guinea. Characters of the male holotype (Papua New Guinea, Bismarck Archipelago, northeastern New Britain Island, Yalom 1000 m, 9.v.1962, Noona Dan Exp. 61-62) are described, and affinities of the new species are discussed. Variations in paratypes and comparisons to other species within the Eastern red-group are specified. The distribution of all 15 members of the Pseudagrion red-group occurring east of Lydekker's line is shown on a map.

Disjunct distributions have long fascinated biologists, particularly those found in the Southern Hemisphere. Gondwanan vicariance has been invoked to explain these patterns, with relatively limited studies having phylogenetically tested this hypothesis. Another intriguing pattern of disjunction involving South America is the American amphitropical distribution, where Western Hemisphere taxa have close relatives either north or south of the tropics. While better known in plants, this pattern is rarely proposed for animals and only phylogenetically tested in a handful of studies on hymenopteran insects. The Manticorini is a tribe of large-bodied, flightless tiger beetles whose members possess a complex distribution pattern attributable to both Gondwanan vicariance and American amphitropical disjunction. Using genomic-scale data we perform phylogenetic analyses to produce a time-calibrated evolutionary history of the Manticorini. With the resultant time tree we perform ancestral range reconstruction in order to recover the historical biogeography of this group. Our results show deep divergence between most manticorine genera, contrasted with young crown ages indicative of recent diversification. Our analyses support Gondwanan vicariance and amphitropical disjunction resulting from recent dispersal as part of the historical biogeography of the tribe. These findings highlight the role of both vicariance and dispersal in shaping diversification and complex modern distributions.

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.

The dragonfly genus Erythemis Hagen, 1861, in the hyper-diverse family Libellulidae Leach, 1815, contains ten species that are found across the Americas. Species relationships have never been resolved for this group, and doing so will provide a framework to understand the considerable interspecific variation present in traits, including genital morphology, abdomen shape, and flight activity. Here, we present the most comprehensively sampled phylogenetic reconstruction for Erythemis based on anchored hybrid enrichment (AHE) data. Using an Erythemis fossil as calibration, we estimated the divergence time of the genus to be about 25 million years ago, around the transition between the Oligocene and Miocene. A reconstruction of the ancestral range of the genus revealed a likely origin in central and South America, with subsequent dispersal into the Caribbean. We also performed a likelihood-based ancestral character state reconstruction to test morphological synapomorphies for the group. Interspecific variation in male genitalia morphology stood out, with different penis characters evolving separately. We also found notable variation in abdomen shape and size among species. Our phylogeny provides a basis for understanding evolutionary relationships of all ten Erythemis species, as well as the origins and timing of character innovations, set in their biogeographical context and with respect to the divergence time of the group.

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.

Fireflies are well-documented in many regions of the USA. However, the presence of flashing fireflies in much of the western United States remains largely unknown. Leveraging citizen science, this study aimed to locate populations of bioluminescent fireflies across Utah. Through a multifaceted public outreach campaign and an interactive website for data collection, citizen scientists were invited to report firefly sightings. Over nearly a decade, the project successfully amassed reports from diverse locations, significantly expanding the known distribution of bioluminescent fireflies in Utah and beyond. Validation of reports was conducted through on-site observations and specimen collection. Despite challenges in data reports (e.g., reports from outside desired area) and public interest management (e.g., protecting private property sites), the project achieved remarkable success, with over 135 unique localities documented. Media coverage, social media engagement, and educational outreach further amplified the impact of the project. Limitations in data quality and public engagement were addressed through iterative improvements in reporting protocols and outreach strategies. Future directions include expanding the project to encompass the western United States and exploring innovative communication strategies. By partnering with organizations in neighboring states, the project aims to create a robust dataset and foster public awareness of these charismatic invertebrates. This study highlights the effectiveness of community-engaged approaches in biodiversity research and underscores the importance of public involvement in scientific endeavors.

A list of checkered beetles (Coleoptera: Cleridae) collected at Finca Las Piedras (Madre Dios, Peru) is presented. Eight new country records for Peru, field observations and taxonomic notes are presented, and distributions are updated for all species herein. The species Phyllobaenus cylindricollis (Gorham, 1886), formerly not known from South America, is supplemented with data from additional geographic regions. Taxonomic problems involving Phyllobaenus cylindricollis (Gorham, 1886), the genus Plocamocera, Enoclerus bipartitus (Schenkling, 1915), E. flavibasis Chapin, 1927 (status restored) and E. dichrous Chapin, 1927 are reviewed and include the assessment of type specimens.

The Vitiaz Arc provides a compelling opportunity to examine biogeographical patterns in the South Pacific. Previously, however, many groups lacked the appropriate taxon sampling to examine this system fully. Fieldwork aimed at improving our understanding of Vanuatu insect diversity and evolution resulted in the collection of two specimens of Melanesobasis bicellulare Donelly, 1984, a species previously known from a single specimen collected 40 years ago. Using a combination of morphological and molecular methods, we are able to associate the female, update distributional data, and record intraspecific variation, including the number of post-discoidal cells. We also use this genus, Melanesobasis Donnelly, 1984, found across Fiji and Vanuatu, to explore biogeographical patterns across the Vitiaz Arc. Our results provide additional evidence of the importance of the Vitiaz Arc in South Pacific damselfly biogeography and show a pattern of vicariance between the two island archipelagos.

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.

High throughput sequencing is an effective method for associating sexually dimorphic species. Increasing the available taxonomic understanding of females is important for biodiversity and conservation efforts. Here, we confirm the association of females caught in copulation with Calicnemia haksik Wilson and Reels, 2003 males in Vietnam using high throughput sequencing (92 loci) and provide the description of the female.

Polarization is a property of light that describes the oscillation of the electric field vector. Polarized light can be detected by many invertebrate animals, and this visual channel is widely used in nature. Insects rely on light polarization for various purposes, such as water detection, improving contrast, breaking camouflage, navigation, and signaling during mating. Dragonflies and damselflies (Odonata) are highly visual insects with polarization sensitivity for water detection and likely also navigation. Thus, odonates can serve as ideal models for investigating the ecology and evolution of polarized light perception. We provide an overview of the current state of knowledge concerning polarized light sensitivity in these insects. Specifically, we review recent findings related to the ecological, morphological, and physiological causes that enable these insects to perceive polarized light and discuss the optical properties responsible for the reflection of polarized light by their bodies and wings. Finally, we identify gaps in the current research and suggest future directions that can help to further advance our knowledge of polarization sensitivity in odonates.

Erotylidae, or pleasing fungus beetles, are a morphologically diverse lineage of Coleoptera notable for the variety of colors and patterns present on their dorsal surface. This study begins the characterization of this diversity and discusses patterns around coloration within Erotylinae. Using spectrophotometer data, we investigated the frequency of certain color motifs across erotyline tribes and discuss geographic patterns in these color motifs. The most frequently observed colors within Erotylinae are brown/black with orange/red maculations in the case of bicolored taxa. In terms of type of maculations, stripes were the most common pattern observed. When summarizing the diversity across major geographic areas, the Neotropical and Indomalay regions displayed the most color variation, followed by the Australasian region.

Insects use their antennae to collect environmental information. While the structural diversity of insect antennae is immediately obvious, the diversity of the minute antennal sensilla that interact with the environmental stimuli and translate them into sensory input, is largely unknown for many insect groups. This includes the beetle family Lampyridae, which includes nocturnal species that use bioluminescent signals during mate search, and diurnal species that rely exclusively on pheromones to identify and locate a potential mate. Relative to their bodysize, diurnal species tend to have larger antennae, and diurnal males have larger antennae than their females. It is generally assumed that antennal size reflects sensilla numbers, but this remains to be tested. We used Scanning Electron Microscopy to document the sensilla diversity of both males and females of three diurnal and four nocturnal firefly species, as well as total sensilla numbers, densities and their distribution along the antenna. We identified 14 sensilla morphotypes across the seven species, including 12 morphotypes that are new for Lampyridae. Based on their putative function we sorted all sensilla into two categories, mechanoreceptors and chemoreceptors. Mechanosensilla (3 morphotypes) were the most abundant and conserved sensilla across firefly species, and the distribution of chemosensilla (9 morphotypes) was unexpectedly variable across species. We hypothesized that the differences in mating signals between diurnal and nocturnal fireflies would be reflected in their chemosensilla counts or densities. As predicted, diurnal and nocturnal fireflies did not differ in their mechanosensilla counts or densities, nor did males and females. In contrast, firefly males had significantly more chemosensilla (and higher densities) than females and the interaction term (activity by sex) was also significant: diurnal males had significantly more chemosensilla than nocturnal males, highlighting the importance of pheromones for diurnal species. Based on a series of predictions, we also identified a pheromone sensilla candidate for each species that will facilitate functional testing in future studies.

Here, we rectify two earlier errors when we published unavailable taxonomical names in iScience. We did not notice that the journal is not permanently archived by an organization independent of the publisher. Therefore, the proposed names are unavailable in the sense of the Code. One tribe and one species are validly described here. The tribe Tibionemini Motyka, Kusy, Arias, Bybee et Bocak, trib. nov. is placed in Pityobiinae (Coleoptera: Elateridae) and Hiekeolycus winkleri Kazantsev et Yamamoto sp. nov. in Erotinae: Dictyopterini (Coleoptera, Lycidae). Both descriptions and illustrations are republished from the original publication to present all necessary information in this article.

Insect coloration has evolved in response to multiple pressures, and in Odonata (dragonflies and damselflies) a body of work supports a role of wing color in a variety of visual signals and potentially in thermoregulation. Previous efforts have focused primarily on melanistic coloration even though wings are often multicolored, and there has yet to be comprehensive comparative analyses of wing color across broad geographic regions and phylogenetic groups. Percher vs. flier flight-style, a trait with thermoregulatory and signaling consequences, has not yet been studied with regard to color. We used a new color clustering approach to quantify color across a dataset of over 8,000 odonate wing images representing 343 Nearctic species. We then utilized phylogenetically informed Bayesian zero-inflated mixture models to test how color varies with mean ambient temperature, body size, sex and flight-style. We found that wing coloration clustered into two groups across all specimens - light brown-yellow and black-dark brown - with black-dark brown being a much more cohesive grouping. Male perchers have a greater proportion of black-dark brown color on their wings as do species with longer wings. In colder climates, odonates were more likely to have black-dark brown color present, but we found no relationship between the proportion of black and temperature. Light brown-yellow showed similar scaling with wing length, but no relationship with temperature. Our results suggest that black-dark brown coloration may have a limited role in thermoregulation, while light brown-yellow does not have such a role. We also find that the odonate sexes are divergent in wing color in percher species only, suggesting a strong role for color in signaling in more territorial males. Our research contributes to an understanding of complex interactions driving ecological and evolutionary dynamics of color in animals.

Petaluridae (Odonata: Anisoptera) is a relict dragonfly family, having diverged from its sister family in the Jurassic, of eleven species that are notable among odonates (dragonflies and damselflies) for their exclusive use of fen and bog habitats, their burrowing behavior as nymphs, large body size as adults, and extended lifespans. To date, several nodes within this family remain unresolved, limiting the study of the evolution of this peculiar family. Using an anchored hybrid enrichment dataset of over 900 loci we reconstructed the species tree of Petaluridae. To estimate the temporal origin of the genera within this family, we used a set of well-vetted fossils and a relaxed molecular clock model in a divergence time estimation analysis. We estimate that Petaluridae originated in the early Cretaceous and confirm the existence of monophyletic Gondwanan and Laurasian clades within the family. Our relaxed molecular clock analysis estimated that these clades diverged from their MRCA approximately 160 mya. Extant lineages within this family were identified to have persisted from 6 (Uropetala) to 120 million years (Phenes). Our biogeographical analyses focusing on a set of key regions suggest that divergence within Petaluridae is largely correlated with continental drift, the exposure of land bridges, and the development of mountain ranges. Our results support the hypothesis that species within Petaluridae have persisted for tens of millions of years, with little fossil evidence to suggest widespread extinction in the family, despite optimal conditions for the fossilization of nymphs. Petaluridae appear to be a rare example of habitat specialists that have persisted for tens of millions of years.