Nineteen females of Cordulegaster boltonii algirica were measured and documented in the field across seven localities in the Rif Mountains and Tazzeka Mountains in northern Morocco in June 2008, June 2015, and June 2024. Their morphological characteristics are described. The variability of body colour pattern is restricted to minor colour details.
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.
A review based on material available at Naturalis Biodiversity Center (RMNH) and images available on iNaturalist and Observation.org shows that Trithemis adelpha, often regarded a synonym of T. aurora, is a valid species and can be identified with relative ease. Trithemis adelpha has a more slender abdomen but is morphologically largely similar to T. aurora. It however differs in the general colouration of the body (red instead of purple) and the extent of black pattern on the thorax and abdomen. Based on the new records it is shown that this Philippines endemic is widespread occurring on all major islands with the exception of Palawan and Negros. Field observations indicate that this species has, compared to T. aurora, a preference for larger waterbodies, and is often found at slow flowing sections of larger streams.
Amazoneura submontana sp. n. (holotype male: Peru, San Martin Regi & oacute;n) is described and illustrated. Males of A. submontana can be distinguished from the other three known members of the genus by the shape of the cerci and absence of a dark ventral cross band behind the metacoxa in mature specimens. With the description of this fourth species of Amazoneura it became clear that some characters attributed to the genus previously are species-specific, so the generic characterization is updated. Furthermore, the species status of A. westfalli is confirmed based on genetic information and a key to males of all species is provided.
The Andaman and Nicobar Islands represent a unique biogeographic region characterized by high biodiversity and endemism, yet molecular studies on insect taxa, particularly Odonata remain limited. This study investigates the phylogenetic relationships and species boundaries among odonate taxa from the islands using mitochondrial 16S rRNA gene sequences. A total of 43 specimens representing 10 morphospecies were analyzed using Maximum Likelihood (ML) and Bayesian Inference (BI) methods. Phylogenetic analyses recovered three well-supported clades corresponding to the families Libellulidae, Coenagrionidae, and Platycnemididae. Genetic distance (K2P) analyses revealed clear interspecific divergence ranging from 4.1-22.6%, with the highest divergence between Ischnura senegalensis and Diplacodes trivialis. Species delimitation analyses using the distance-based methods ABGD and ASAP identified 10 molecular operational taxonomic units (MOTUs), fully congruent with morphological identifications and genetic distance patterns. These results demonstrate the effectiveness of DNA barcoding for resolving taxonomic boundaries and emphasize the importance of integrative molecular approaches for biodiversity assessment and conservation in island ecosystems.
The maintenance of colour polymorphisms in natural populations is often explained by contrasting selective forces acting on the life cycle stage that shows the polymorphism. Nevertheless, in animals with complex life cycles, selection during the larval stage, which usually is the longest development phase and might accumulate 99% of overall mortality, could be a determinant force if the genes that affect adult colour have pleiotropic effects on larval phenotype. Among odonates, female colour polymorphism is under selection during the adult stage, but very little is known about its effect during larval development. In this paper, we studied the coenagrionid damselfly Ischnura graellsii which shows three genetically determined female morphs. We explored the effects of the colour polymorphism and sex by undertaking a selection black-box experiment in microcosms, repeated over two years, to evaluate whether different densities and food stress may lead to variation in emerging adult morph frequencies and sex-ratios. We found that female morph frequency did not significantly differ between density treatments or years, and detected a significant effect of treatment on sex-ratio and body size, but not on developmental time. Furthermore, we found significant between-year variation in body size and developmental time. We conclude that the effect of colour phenotype on larval competitiveness seems limited and discuss the importance of experiment replication to increase confidence in the generality of results.
A new species of dragonfly, Lyriothemis keralensis sp. n. is described from the coastal plains adjoining the Western Ghats of Kerala, southern India, based on a male holotype (IBC-CD161) and a female paratype (IBC-CD310) (type specimens are deposited in the Biodiversity Lab Research Collections, currently held at the National Centre for Biological Sciences, Bengaluru). This taxon was hitherto misidentified as L. acigastra (Selys, 1878) from which it differs in having leaner abdomen, and differently shaped secondary genitalia and caudal appendages. Information on its biology and ecology are provided.
The Atlantic Forest, one of the world's most threatened biodiversity hotspots, is home to a rich diversity of Odonata, a group with great potential for further research in this phytophysiognomy. Considering this, the aim of this study was to update the data on Odonata species found in four conservation units of the Atlantic Forest biome in the states of S & atilde;o Paulo, Minas Gerais and Espirito Santo, highlighting their diversity and distribution. Biological material was collected through active sampling carried out in four conservation units of the Atlantic Forest biome: Carlos Botelho State Park, Serra do Mar State Park-N & uacute;cleo Santa Virginia, Serra do Papagaio and Capara & oacute; National Park. A total of 447 individuals were sampled, distributed in 21 species, 12 genera and six families. The known distribution of Heteragrion brianmayi, Heteragrion freddiemercuryi and Heteragrion gorbi with these species now recorded in the state of Minas Gerais. In addition, the presence of Rhion aeschna punctata, a species endemic to Brazil, was recorded, as well as a high number of species from the genus Heteragrion, such as Heteragrion freddiemercuryi and Heteragrion ovatum, which had not been documented since 1973. This new information helps fill gaps in our understanding of Odonata diversity and provides a foundation for future ecological and evolutionary studies, in addition to contributing important information for the conservation of the group.
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.
Hetaerina giselae sp. n. is described and illustrated based on specimens collected at Pico do Itamb & eacute; State Park, Minas Gerais, Brazil. Integration of morphological and molecular data (COI) supports the recognition of the new species. The new species can be separated from its morphologically closest congeners, such as Hetaerina longipes Hagen in Selys, 1853, and Hetaerina westfalli R & aacute;cenis, 1968, by a combination of characters of the male anal appendages, female intersternite, and general anatomical features. In addition, we present the description of the larva, highlighting the main morphological differences that distinguish it from adults and other known larvae of the genus.
Female-limited colour polymorphism is widespread in Odonata, particularly in the Coenagrionidae, where it is determined by simple Mendelian inheritance. In contrast, female-limited colour polymorphism in Calopterygidae is restricted to some populations of the Palaearctic Calopteryx splendens complex, whose males have blue-spotted wings and females occur either as gynochromes with transparent wings or as androchromes with dark brown-spotted wings. A behavioural study in two river basins in southern Italy suggested that reduced harassment by males of the syntopic Calopteryx haemorrhoidalis might favour androchrome females, which could otherwise suffer increased predation due to their less cryptic coloration. However, the role of interspecific harassment in maintaining this polymorphism has not been further tested. Here, the results of three field surveys conducted in southern Italy in 2011, 2020, and 2021 are reported, expanding the known range of polymorphic C. splendens populations to 22 sites across seven river basins. Two distinct androchrome morphotypes were identified, differing in the extent of wing pigmentation: one widespread in the Basilicata and Campania regions and another restricted to the Crati river basin in the Calabria region. The proportion of androchrome females was associated with the river basin and the density and proportion of conspecific males, not with the density or proportion of C. haemorrhoidalis males. Contrary to earlier behavioural evidence, these results suggest that female-limited polymorphism is not maintained by interspecific harassment but by intraspecific mechanisms such as male mimicry or frequency-dependent selection.
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 endemic Hawaiian damselflies of the genus Megalagrion have a complex taxonomic history. Classification within Megalagrion has predominantly focused on morphology and geography, followed by more recent and extensive molecular work. This combined effort has increased our understanding of the group, provided insight into existing taxonomic questions, and raised new questions. Here we outline the historical classification and nomenclature leading up to the present understanding of Megalagrion. Additionally, we discuss taxonomic issues that remain and make recommendations for future work.
Dragonflies (Insecta: Odonata) are sensitive to anthropogenic disturbances that affect water quality, siltation, and riparian canopy cover; but these characteristics also vary with waterway size. We used the visual scan method to sample adult odonates in a 100 x 10 m plot at 20 sites (sampled six times each) on 12 waterways of different size (1-50 m wide) in forested habitats in northwestern South Carolina, USA. We used AICc to compare 'best-subset' linear models evaluating the effects of waterway width and nine other habitat characteristics, considered independently and as a combined Habitat Integrity Index (HII), on odonate communities. Mean adult abundance (log(10) transformed) and species richness (improved Chao estimated) were only predicted in linear models by waterway width, and were significantly greater in large waterways (> 10 m) than small (< 10 m; t-tests). Simpson's diversity (Chao estimated) was only predicted by the HII and was only positively correlated with the index when waterway width was included. The species composition of odonate communities inhabiting large waterways was also significantly different than in small waterways (NMDS and PERMANOVA analyses). Communities on small waterways were significantly nested subsets of species in communities on larger waterways, whether waterways were ordered by waterway width or grouped in 'large' and 'small' categories (NODF nestedness analyses). Forest specialists needing shady habitats used all waterways, but large waterways also supported habitat generalists preferring sunny areas and river specialists. Because large waterways already have open canopies, differences in waterway width may complicate the effects of anthropogenic disturbance.
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.
An inventory of Nigeria's Odonata and their distribution in each of the country's ecological zones are presented for the first time. Records is based on occurrence information from databases, verified literature, and observations from the field between 2020 to 2025. Databases included Odonata Database of Africa with records as far back as 1905 and iNaturalist from September 2012 to April 2025. Red List Categories were assigned to all species following the IUCN global Red List assessments but with modification for some species, thereby creating a proposed national Red List. With a total of 4630 records, the number of Odonata species known and confirmed to occur in Nigeria is 249. Some Odonata species previously known to occur at some particular localities were no longer found there indicating a change in diversity from 1905. A list of odonate species which are found near the Nigerian borders in neighbouring countries but have not been confirmed in Nigeria are given. Comments are also made on Odonata species unlikely to occur in Nigeria but reported in literature.
The larva of Anisopleura yunnanensis Zhu & Zhou, 1999 was identified by DNA barcode matching with the adult, and the morphology of the final instar larva is described and illustrated in color. Differences among known larvae of this genus is discussed, and a comparative table is provided.
The genus Crocothemis Brauer, 1868 (Odonata: Libellulidae) has two species distributed in the Indian region: Crocothemis erythraea (Brulle, 1832) and C. servilia (Drury, 1773). Crocothemis servilia is a common species in the lowlands of southern India, whereas C. erythraea appears to be a rare species restricted to the higher elevations of the southern Western Ghats. The differentiation of these closely similar species is somewhat problematic in the field, with some authors stating that only C. servilia is present in southern India. We provide taxonomic characteristics that are useful for diagnosing these altitudinally separated species based on their male genitalia. Molecular analysis based on the mitochondrial COI gene recovered high-elevation samples from the Western Ghats within the C. erythraea clade. Furthermore, samples from the lower elevations of the Himalayas and Western Ghats were retrieved within the C. servilia clade, confirming the presence of both species in the Western Ghats. Phylogenetic analysis of C. erythraea populations from the Western Ghats and Himalayas revealed high genetic similarity, with 99.5% identity in COI and similar to 98.95% identity in ITS2 sequences. This confirms that the taxon represented in the montane regions of the Western Ghats is C. erythraea, whereas the lowland taxon is C. servilia. Important morphological features for comparison of mature insects, field behavior, and the updated distribution of the two species in India are also discussed. The isolation of C. erythraea in the subtropical and temperate montane forests of the Southern Western Ghats, despite its phylogenetic similarity to Himalayan populations, suggests that a relict distribution was likely shaped during the Pleistocene glaciations.
A new genus and species of Coenagrionidae (Zygoptera: Odonata) is described from a remote and protected area in the Brazilian Amazon. The new taxon, Kuiagrion hamadae gen. n. et sp. n., displays a unique combination of morphological features, including a caudally projected pronotum in both sexes, fused ventrobasal and dorsal branches of the cerci, a genital ligula with distinctive lateral lobes, and reduced paraprocts. Diagnostic features, illustrations of both sexes, and molecular data based on COI sequences are provided. Phylogenetic analyses using Maximum Likelihood and Bayesian Inference place this new taxon within the core Coenagrionidae, although its morphological traits suggest affinities with the 'ridged frons' clade. This incongruence between molecular and morphological data raises new questions regarding character interpretation and phylogenetic signal within the family. This discovery highlights the importance of systematic surveys in understudied Amazonian ecosystems. Moreover, it underscores the relevance of longterm research and monitoring programs, such as ICMBio's Monitora Aqu & aacute;tico, in advancing biodiversity knowledge and reducing existing knowledge gaps.
