Taxonomy of the genus Cordulegaster Leach in Brewster, 1815 in the Eastern part of the Western Palaearctic is poorly resolved. A two-step approach was applied: sequences of mitochondrial and nuclear DNA fragments were used to sort specimens; poorly known or new taxa with their phenotypic variation were described. The existence of two traditional groups (boltonii- and bidentata-group) was confirmed. Cordulegaster coronata Morton, 1916, however, belongs to a different group. Molecular-analysis supported three known and one new species (C. heros Theischinger, 1979, C. picta Selys, 1854, C. vanbrinkae Lohmann, 1993, and C. kalkmani sp. nov.) in the boltonii-group. In the bidentata-group, all specimens from West-Turkey belonged to C. insignis Schneider, 1845, all specimens further east to a complex of four closely related species, which we name charpentieri-complex (C. amasina Morton, 1916, stat. rev., C. mzymtae Bartenev, 1929 C. charpentieri (Kolenati, 1846), stat. rev. and C. cilicia sp. nov.). The following taxa: C. insignis nobilis Morton, 1916, syn. nov., C. nachitschevanica Skvortsov and Snegovaya, 2015, syn. nov. C. plagionyx Skvortsov and Snegovaya, 2015, syn. nov. and the Caucasian subspecies C. insignis lagodechica Bartenev, 1930, syn. nov., were synonymized with C. charpentieri. Finally, we provide a key for all Western Palaearctic Cordulegaster.

Aeshnidae Rambur, 1842 are impressive large insects distributed worldwide. Currently, over 500 species are recognized. Nevertheless, the phylogeny of this family is not completely understood. We applied molecular phylogenetic analysis using two popular phylogenetic markers, the mitochondrial COI gene fragment (barcoding sequence) and the nucleic ITS region, containing the ITS1, 5.8S rRNA, and ITS2 sequences. We used available and credible published sequences and 96 newly sequenced specimens. Our analysis involved all West Palaearctic species, all but one genera of the Holarctic Aeshnidae, and most genera worldwide, and is by far the largest molecular study of this family. The topology of all trees created with different algorithms and genes is in favour of the current taxonomic concept, with some remarkable outcomes. Aeshna Fabricius, 1775, was found to be diverged into several branches, especially with respect to the COI gene. Although it appeared not monophyletic in phylogenetic reconstructions based on the ITS region, the analysis of COI and joint analysis suggest its monophyly in the current taxonomical sense, with one notable exception. Aeshna isoceles (Müller, 1767) has fallen out of Aeshna in all analyses, so a new monophyletic genus, Isoaeschna gen. nov. is introduced for it. The genus Brachytron Evans, 1845 tightly clustered with Aeschnophlebia Selys, 1883, Epiaeschna Hagen in Selys, 1883, and Nasiaeschna Selys in Förster, 1900. Thus, we suggest subsuming these four genera under the priority name Brachytron. Tetracanthagyna Selys, 1883 clusters as expected with Brachytron in the ITS tree, but is an independent ancient clade of its own in all COI trees. The genus Polycanthagyna Fraser, 1933 syn. nov. is synonymised to Indaeschna Fraser, 1926. On the species level, we suggest that the American Aeshna septentrionalis Burmeister, 1839 be treated as a subspecies of A. caerulea (Ström, 1783), Aeshna caerulea septentrionalis. We synonymize Gynacantha hyalina Selys, 1882 with Gynacantha subinterrupta Rambur, 1842. Our analysis provides new insights on the tight relationships of the circumboreal species Aeshna juncea and A. subarctica and the intraspecies phylogeny of Aeshna juncea.

Iran has a complex dragonfly fauna influenced by contacts and overlaps of different geographical zones. Its fauna is dominated by Eurosiberian taxa. However, the SE Province Sistãn-va-Baluchestãn is rich in oriental species, many of which having their western distribution limit in Iran. In NE-Iran, Irano-Turanian elements live and in the S- and SW-Iran African species are found. The Iranian Odonata fauna seems well studied, however, a closer look reveals many uncertainties and confusion, some records coming clearly from misidentification whereas other, which were missing proofs of correct identification remains to be confirmed. Even today, every new collecting trip reveals species new for Iran whereas species new for science are still detected, although rarely. In this checklist we include seven taxa new for Iran: Stylurus ubadschii (although a male of uncertain origin is recorded in Schmidt (1954), Ischnura senegalensis (although two uncertain records were published by Martin (1912) and Schmidt (1954), Coenagrion ponticum, C. lunulatum, C. pulchellum, Lestes macrostigma, and Calopteryx splendens tschaldirica. We critically checked all available data, including all published records. Fourteen taxa have been rejected, or placed in the category for need of confirmation. Till the end of 2017, 100 autochthonous taxa of dragonflies and two migratory species could be confirmed to be or have been present in Iran. We provide distribution maps, created after evaluation of published data and containing our own data from 12 trips to Iran, travelling over 35000 km in the country. Over 200 new localities are integrated. Taxonomic confusion is reduced by rejecting the following taxa for Iran: Calopteryx splendens mingrelica, C. hyalina, Erythromma najas, Aeshna cyanea, Gomphus davidi, and Sympetrum sinaiticum. We regard the taxa Gomphus amseli and G. schneiderii transcaspicus as synonyms of G. schneiderii, and Onychogomphus forcipatus lucidostriatus as a synonym of O. f. albotibialis.

Taxonomy of the genus Cordulegaster Leach in Brewster, 1815 in Greece is not completely understood. The taxonomic status of the subspecies C. helladica buchholzi (Lohmann, 1993), C. helladica kastalia (Lohmann, 1993), and C. heros pelionensis Theischinger, 1979 was still unclear. We applied a molecular genetic approach using sequences of mitochondrial and nuclear DNA fragments—cytochrome c oxidase I (COI) and Internal Transcribed Spacer 1 (ITS1). This approach revealed that specimens presently assigned to C. heros pelionensis should be considered as conspecific to the nominate subspecific taxon making C. heros a monotypic species. Two major monophyletic lines were found within the Greek representatives of the species grouped around C. bidentata Selys, 1843: the clade of the European endemic C. bidentata and the clade composed of three species: C. helladica (Lohmann, 1993), C. buchholzi (stat. nov., raised to species level), and C. insignis Schneider, 1845. Cordulegaster helladica is restricted to the Peloponnese. Cordulegaster buchholzi is not restricted to the Cyclades as previously thought, but widespread from the Cyclades over the island Euboea to south-east mainland Greece reaching in the west near Mount Parnassos, where it hybridize with C. bidentata. Hybridization between C. bidentata and C. buchholzi was detected at the Castalian Spring, where in ancient times the Oracle of Delphi was located, and some kilometres east of the Castalian Spring. These hybrids had been formerly named C. helladica kastalia. In the case of C. insignis montandoni St. Quentin, 1971 we have investigated specimens some kilometres away from the type locality in Romania, which all revealed hybrids between C. bidentata and C. insignis. However, we do not know if specimens phenotypically looking like C. insignis from further west in the SE Balkans represent isolated population of C. insignis within the range of C. bidentata or belong to a broader hybrid zone between C. bidentata and C. insignis.

In this study, we present the first attempt at a molecular phylogenetic analysis of the entire family of Cordulegastridae involving 60% of its known species. Our analysis is in favor of reclassification of the members of the family into four genera: (i) the monophyletic genus Anotogaster Selys, 1854, with the number of known species reduced by three synonymizations; (ii) the genus Cordulegaster Leach in Brewster, 1815 including all members of the boltonii group and, as a preliminary solution, the American species C. virginiae Novelo-Gutiérrez, 2018 and, very tentatively, C. diadema Selys, 1868. The bidentata group forms a genus of its own, for which we restored the name Thecagaster Selys 1854, stat. rev. Cordulegaster pekinensis McLachlan in Selys, 1886, currently considered as Neallogaster pekinensis, was placed by us in Thecagaster as well. The genus Neallogaster Cowley, 1934 needs further investigation involving all remaining species listed in it. The genus Zoraena Kirby, 1890, stat. rev., was recovered to accommodate the remaining American species of Cordulegaster. We synonymized three species of Anotogaster: Anotogaster gregoryi Fraser, 1923 = Anotogaster xanthoptera Lohmann, 1993, syn. nov.; Anotogasterkuchenbeiseri (Förster, 1899) = Anotogaster antehumeralis Lohmann, 1993, syn. nov.; Anotogaster kuchenbeiseri (Förster, 1899) = Anotogaster cornutifrons Lohmann, 1993, syn. nov., based on examination of the existing type specimens. The type of specimens of A. klossi Fraser, 1919 = A. flaveola Lohmann 1993 syn. confirm., were also examined, and their synonymy was confirmed. The isolated populations of A. sieboldii (Selys, 1854) from the archipelagos of Okinawa and Amami Oshima in Japan, respectively, should be regarded as separate species, which will be described elsewhere. Furthermore, we suggest the synonymization of Cordulegaster parvistigma Selys 1873 syn. nov. with Thecagaster brevistigma (Selys 1854) comb. restaur.

Coenagrion persicum was described by Heinrich Lohmann in 1993 on the basis of a single male and two larvae captured in 1937 by E.W. Kaiser in Lorestãn Province (W-Iran). In June 2015 two of the authors (TS and DI) rediscovered individual-rich populations of this species in two Iranian provinces (Lorestãn and Esfahãn). We could confirm the structural differences of the male appendages between C. persicum and C. pulchellum based on a larger number of specimens than in the original description. The structural differences from C. pulchellum in females and their phenotypic variation pattern is described. Coenagrion persicum and C. pulchellum are also genetically distinct regarding two nDNA gene fragments: arginine methyltransferase (PRMT) and phosphoglucose isomerase (PGI). In contrast with C. pulchellum, C. persicum prefers small springs and running waters with rich herbal vegetation. Our faunistic data indicate that the species is present in the mountains between 1800 m and 2300 m a.s.l.. The species seems to be restricted to W-Iran, where it co-occurs with other rheophilic species.