Male dragonflies engage in aggressive aerial contests to establish breeding territories. Using field stereographic recordings of Trithemis aurora, we examined dragonfly behavioural objectives during these encounters. Unlike predatory pursuits, in which intercept trajectories minimize time-to-contact, male T. aurora steer to keep their opponent in a slightly elevated position within their frontal visual field, modulating speed to avoid direct collision. These contests feature frequent role reversals, with evenly matched rivals alternating between chaser and evader. The manoeuvres observed during these exchanges, including looping and spiralling flight, emerge from the underlying pursuit objectives. During territorial conflicts, males exhibit exceptional agility with centripetal accelerations up to 6g. Despite this high performance, individuals spent approximately one-third of flight time gliding in short bursts, even during close combat. These findings show that complex aerial contests can arise from simple control objectives constrained by sensorimotor limits.
Species traits are an important facet of biodiversity and are useful for testing many ecological and evolutionary hypotheses. Many initiatives to centralize species traits have emerged in recent years, but there are still large gaps in species traits' knowledge in the literature. Odonata (dragonflies and damselflies) are present in most freshwater and surrounding ecosystems and are important indicators of freshwater health and conditions across the land-water interface. They are also important predators and prey both as larvae and adults and are vital to land-water energy transfers and community functioning. Here we present OdonTraits Europe, a database aggregating traits of all 143 European resident Odonata species. Our database compiles 43 traits representing adult and larvae morphology, life history, behaviour, phenology, and other ecological attributes, along with species legal, endemism, and conservation status, with a taxonomic coverage of >95% for all traits. Accessible and robust coverage of Odonata species traits will help to advance knowledge and applications involving this sentinel of the freshwater realm.
Mercury (Hg), and specifically methylmercury (MeHg), is a contaminant of global concern to humans and wildlife, but there is still limited understanding of its effects on many taxa. Amphibians are closely associated with water, where Hg is converted to MeHg, and high concentrations of MeHg can reduce survival of amphibians in the wild. However, limited non-lethal proxies exist for estimating MeHg bioaccumulation in amphibian larvae, which could be used to reduce destructive sampling and allow sampling of imperiled species. We evaluated whether tail clips were indicative of whole-body MeHg concentrations of larval amphibians, whether dragonflies were an effective bioindicator of Hg concentrations of larval amphibians, and compared MeHg bioaccumulation in predatory caudate (salamanders, newts) and non-predatory anuran (frogs, toads) larvae. Tail-clip and whole-body MeHg concentrations were strongly correlated, especially for caudates. There was high variability among sites and species, but caudates had higher MeHg than anurans, and MeHg concentrations of caudates and anurans were strongly correlated. Dragonflies were a weak indicator of MeHg for anurans but strong indicators for larval caudates, likely because caudates and dragonflies are carnivorous and occupy similar trophic positions. Our study revealed that sampling tails can be an effective non-destructive index of whole-body MeHg for larval amphibians and demonstrates differences in MeHg bioaccumulation related to trophic position in larval amphibians and dragonflies. All post-embryo life stages for a broad suite of amphibian species can now be sampled non-lethally for MeHg, allowing for a broader examination of population-level effects and focus on imperiled species that cannot be sampled destructively.
A new subspecies Thecagaster charpentieri iranica ssp. nov. is described. It is a large and impressive cordulegastrid restricted to Southeast Iran. This region represents the southeastern limit of the genus Thecagaster Selys, 1854 and of the family Cordulegastridae in the West Palaearctic. Beside its size, as one of the largest dragonflies in the region, it also exhibits morphological differences in both exuviae and imagines when compared with Thecagaster c. charpentieri (Kolenati, 1846). The adults from Fãrs and Kermãn Provinces in Iran and the exuviae of this subspecies are described in detail. The process of emergence is documented. A phylogenetic comparison of the specimens of the new subspecies with the nominotypical taxon and other closely related species of the genus based on the analysis of COI and ND4 genes of mtDNA is shown, and the history of Morton's "race nobilis" is discussed.
Phyllogomphoides biguttatussp. nov., from western Ecuador, is described based on reared adults of both sexes and larvae collected in slow parts of small forest streams in hilly landscapes. This species belongs to the semicircularis-group of species and is closely related to P. semicircularis (Selys Longchamps) and P. insignatus Donnelly. Phyllogomphoides insignatus probably represents the adelphotaxon of the new species. A differential diagnosis is given to distinguish these closely related species. The new species can be separated from all known Phyllogomphoides Belle by its unique thoracic color pattern with pleural and tergal parts of pterothorax entirely brown to dark brown except for a pair of large yellow drop-shaped antehumeral markings.
Paragomphus Cowley, 1934 is a large palaeotropical dragonfly genus with four species previously described from Madagascar. The species identity of three of them requires confirmation, and only Paragomphusfritillarius (Selys, 1892) did not raise any taxonomical doubts. In this paper, a new species, Paragomphus sofiaesp. nov. from the Sofia River basin in lowlands of northern Madagascar, is described and compared to superficially very similar P. fritillarius. Identification of both species was possible only by comparing their hamules with the type specimens of P. fritillarius in the Selys' collection, because the literature contained neither illustrations nor detailed descriptions of its secondary genitalia. Regardless of the great similarity in the colour pattern, these species have turned out to be well-defined and differ by their notably distinct hamules and caudal appendages. They also seem to be spatially and ecologically separated: although both inhabit clearwater and sandy watercourses, P. sofiae has been recorded in open large, braided rivers so far and P. fritillarius in smaller rivers and streams. Considering the new knowledge of confusing interspecies similarity and species-specific hamules and cerci, all previous records of P. fritillarius require confirmation; the discovery of further species from the fritillarius-group is potentially possible.
Rhyothemis variegata (Linnaeus, 1763) and R. phyllis (Sulzer, 1776) are conspicuous, widespread and well-known species described in 18th century, the former by Linnaeus himself. They are considered broadly co-occurring in south-east Asia, with the former extending to the Indian subcontinent and the latter to Sundaland and Oceania. They are assumed to strongly differ in wing coloration, however this concerns females only, while the differences in males were characterised by Ris (1913) and Fraser (1936) as subtle. This circumstance is scarcely known to people interested in dragonflies, so that many of them got an impression that in the regions where both species co-occur, R. variegata is represented by females only. No structural difference between these two species has ever been reported. Fifteen years ago the first author supposed that the dragonflies associated with these two species names in fact represent the same biological species. Here, this statement is proved by sequencing two molecular markers, the mitochondrial COI gene fragment and the nuclear histone H3-H4 region, from eight females collected in the same swarm in Cambodia and classified to four distinct phenotypes, of which one formally corresponds to R. phyllis and three to R. variegata. The sequences were nearly identical: only three positions in COI and four (one with a two nucleotide indel) in the histone H3-H4 region (ca 0.5% of positions in both cases) were variable, without correspondence to phenotypes. Two specimens of R. variegata from Western Ghats of India shared the same haplotypes. Analysis of the COI sequences from GenBank proved the same near identity and the lack of correspondence to identifications as R. phyllis or R. variegata. Based on this, R. phyllis is claimed to be a junior subjective synonym of R. variegata. The nominotypical subspecies of the former is re-attributed to the latter, as Rhyothemis variegata phyllis comb. nov., while validity of other subspecies earlier proposed under R. phyllis is left for further studies.
Paragomphus matroka sp. nov. (holotype ♂: Madagascar, Taolagnaro District, Iaboakoho, Réserve de Ressources Naturelles de la Forêt Naturelle de Tsitongambarika, Ampasy; Lat. -24.57840°, Lon. 47.14493°; 4.xii.2024; to be deposited in RMNH, Leiden), is described as new to science. The new endemic species is known only from the holotype, the paratype deposited in the MNHN, Paris, and an additional specimen deposited in NHRS, Stockholm. It has been recorded from three localities in the eastern part of the island, scattered over a distance of 1,033 km, within the Madagascar Humid Forests ecoregion. Despite the pronounced variation in the colour pattern, the three known specimens are interpreted as conspecific based on concordant diagnostic morphological characters, particularly the nearly identical structure of the secondary genitalia and cerci. The new species is related to P. fritillarius (Selys, 1892) and P. sofiae Bernard & Daraż, 2026. From these two more brightly coloured, spotted Hooktail species, P. matrokasp. nov. differs in its considerably darker colouration, a reduced pattern of smaller light markings on the synthorax, and clearly different secondary genitalia. The discovery of a new species underlines the need for additional intensive odonatological studies in Madagascar. Improving knowledge of species distributions, taxonomy, phenology and ecological requirements is crucial, especially in the context of threat assessments and conservation of endemic odonate fauna.
Pancreatic ductal adenocarcinoma (PDAC) is characterized by an immunosuppressive tumor microenvironment (TME) in which cancer-associated fibroblasts (CAFs) play pivotal roles in shaping therapeutic responses. Among these, MHC-II-expressing antigen-presenting CAFs (apCAFs) modulate CD4 T-cell activity, yet their contribution to the antitumor immune response remains unclear. Using tumor clones of the KPC murine PDAC model differing in sensitivity to immune checkpoint blockade (ICB), we show that immunosensitive (sKPC) tumors exhibit greater apCAF infiltration than resistant (rKPC) tumors. Reducing apCAF numbers in sKPC tumors impaired responsiveness to ICB, highlighting apCAFs' role in mediating effective antitumor immunity. Ex vivo assays revealed that apCAFs from both models activate CD4 T cells and induce regulatory T-cell (Treg) differentiation. However, single-cell transcriptomics revealed that rKPC apCAFs promote Tregs with heightened immunosuppressive signatures, driven by distinct chemokine signaling. We identified elevated CCL22 expression and signaling in rKPC-derived apCAFs as a contributor to enhanced Treg-mediated suppression. Functional blockade of CCL22 reduced TGF-β secretion by rKPC apCAF-induced Tregs, supporting a mechanistic role for this pathway in fostering an immunosuppressive TME. These findings position apCAFs as regulators of CD4 T-cell antitumor immunity in PDAC and suggest that modulating apCAF-T-cell interactions could offer strategies to enhance immunotherapy efficacy.
A description of the adult and last instar larva of Nannophya pygmaea Rambur, 1842 is presented, based on reared material from Vietnam and additional specimens obtained from Peninsular Malaysia and Singapore. Adult morphology of both sexes is documented to ensure accurate species confirmation and to demonstrate consistency with previously established diagnostic characters. Updated distributional data for Nannophya Rambur, 1842 in Asia are synthesized from verified field records, curated online biodiversity repositories (GBIF and iNaturalist), and published literature. Diagnostic comparisons of N. pygmaea with N. koreana Bae, 2020 as well as with other members of Brachydiplacine are provided. The taxonomic status and distribution of N. pygmaea are discussed. The essential baseline data for future systematic, biogeographic, and conservation studies are provided.
The present paper reports Macromia sombui Vick, 1988 for the first time from India, almost 36 years after its first description from Royal Chitwan National Park of Nepal in 1988. Macromia calliope flavocolorata Fraser, 1922 and Macromia cingulata Rambur, 1842 are reported here for the first time from the northeast India based on specimens collected from the fringe area of Raimona National Park, Kachugaon Division, Bodoland Territorial Council (BTC), Assam, India. In addition, this paper incorporates Macromia cupricincta Fraser, 1924 into the Odonata list of Assam.
The Drug Rediscovery Protocol by K. Verkerk, et al., operationalized nationwide biomarker-guided, off-label precision oncology. Yet outcomes (15.7% response rate) mirror a decade of studies, indicating a single biomarker-drug strategy ceiling. Advancing efficacy will require customized, individualized combinations, consistent with the hallmarks of cancer complexity and the I-PREDICT (Investigation of profile-related evidence determining individualized cancer therapy) style clinical studies framework, which shows that outcomes scale with greater biomarker matching.
Early phase clinical trials (EPCT) are essential for evaluating new cancer treatments. However, disparities in patient enrollment persist, especially affecting older adults, minority groups, and individuals of lower socioeconomic status. In Spain, despite its leading role in European clinical research, systematic analysis of inequalities in EPCT participation remains underexplored. This narrative review identifies and discusses key barriers affecting patient access to EPCTs in Spain, including strict eligibility criteria, socioeconomic and geographic barriers, differences in hospital resources, and biases among clinicians when selecting patients. Recommendations provided include revising eligibility criteria, improving training for healthcare professionals, enhancing referral networks, providing targeted education for patients, and addressing socioeconomic and geographic constraints. Addressing these barriers is essential to ensure equitable EPCT participation in Spain and to improve overall cancer outcomes.
Here, we describe, illustrate, and diagnose the F-0 exuvia of Peristicta janiceae Pessacq & Costa, 2007, collected in the state of Minas Gerais between May and November 2024. The larva can be separated from other congeners by a combination of morphological characters, including mandibles and premental setation.
Specimens of the Pseudagrion blue-group allied to P. microcephalum (Rambur, 1842) were studied with special attention to the male caudal appendages and genital ligulae. The males of P. microcephalum are morphologically re-characterised, and the species is considered to have a limited range that includes India, Pakistan, Nepal, Bangladesh, and Sri Lanka. The status of P. siamense Fraser, 1922 is revised and considered a distinct species, with the scientific name removed from synonymity and a neotype designated and described (♂, 7.viii.1972, stream at Ang Kep Nam-Bang Phra environments, South Chon Buri, Thailand, approximately 13.205°N, 100.975°E, G. von Rosen leg., GvRosen no. 1753; deposited at the Zoological State Collection Munich, Germany). Two new species are erected and figured: P. crenatumsp. nov. from Australia (holotype ♂, 2.x.1915, Caboolture, Queensland, Australia, approximately -27.084°N, 152.951°E, R.J. Tillyard leg., no. 14110; deposited at the Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt am Main, Germany); and P. piratasp. nov. from the Philippine Islands (holotype ♂, 17.i.1992, Barili, Montayupan falls, Cebu Island, Philippines, approximately 10.101°N, 123.535°E, Th. Borromeo Jr. leg., ex. Coll. Roland A. Müller, no. 975694; deposited at the Naturalis Biodiversity Centre Leiden, the Netherlands). The range of P. coarctatum Lieftinck, 1932, a species previously known only from a few records at Jayapura and Sentani Lake in northeastern Indonesian West Papua, is extended to Sulawesi, the Moluccas and the Solomon Islands; the male is morphologically re-characterised and illustrated, and the female described. Photographs of the holotypes of P. microcephalum, P. coarctatum and P. starreanum Lieftinck, 1949 are provided. In addition, P. stainbergerorum Marinov, 2012 stat. nov. is proposed, based on distinct morphological differences from P. microcephalum. A key to males of the Pseudagrion blue-group is provided, including illustrations of the male caudal appendages and partly of the genital ligulae for all species treated. Pseudagrion daponshanensis Zhou & Zhou, 2007 is transferred to the genus Coenagrion.
Protosticta hopkinsi sp. nov. is described from the Central Highlands of Vietnam (Holotype ♂: Vietnam, Lam Dong Province, Lac Duong District, Thien Thai waterfall, 12.14472°N, 108.52944°E, alt. 1,559 m a.s.l., 29 April 2025, Zoological Collection of Duy Tan University). The new species can be easily distinguished from all other species in the Protosticta trilobata group by the combination of the yellow stripe on dorsal synthorax of male and female, and the shape of the apical part of the paraprocts.
The final instars of Nehalennia integricollis Calvert and Nehalennia pallidula Calvert are described in detail and illustrated based on specimens from Florida and Texas.Nehalennia integricollis has only 1 prominent seta on each side of the prementum, same as the sympatric N. gracilis Morse and N. irene (Hagen); it differs from both those species by 1) proximal portion of epiproct and paraprocts darker than the distal part vs. not darker, and 2) posterolateral corners of head with 3-6 small spinules with dark bases vs. 10 or more spinules with dark bases or 3-6 spinules with pale bases. Nehalennia pallidula resembles N. minuta (Selys) in possessing 3 or 4 prominent setae on each side of the prementum; it differs in having a slightly larger prementum (length 1.70-2.05 mm vs. 1.60-1.65 mm, width 1.43-1.58 mm vs. 1.35-1.40 mm). Further diagnostic notes to distinguish the nymphs of the five New World species of Nehalennia are provided.
Drepanosticta minhanhianasp. nov. (holotype ♂: 15.26416° N, 121.35115° E; 69 m a.s.l.; deposited at Cavite State University, Philippines) is described from Luzon Island, the Philippines, based on specimens of both sexes. The new species can be distinguished from its congeners by the differential characters of the male prothorax and by the structure of anal appendages. Additional descriptive notes, as well as detailed morphological photographs and illustrations of both the male and female of D. halterata (Brauer, 1868), are also provided.
The genus Allopodagrion Förster, 1910 includes Neotropical damselflies distributed from southeastern Brazil to northern Argentina, with only A. brachyurum De Marmels, 2001 previously known in the larval stage. Here, we describe the larva of A. contortum (Hagen in Selys, 1862) based on specimens collected in Pico do Itambé State Park (Minas Gerais, Brazil). The relationship between the larva and the adult was confirmed through molecular analyses (COX1 gene). The larva of A. contortum, which can be distinguished from A. brachyurum by tubercles of the head, pronotum, and mouthpart morphology.