The genus Coenagrion Kirby, 1890 (Odonata: Coenagrionidae) in the Russian part of the Caucasus Author Kosterin, Oleg E. 0000-0001-5955-4057 Institute of Cytology & Genetics SB RAS, Acad. Lavrentyev ave. 10, Novosibirsk, 630090, Russia. kosterin@bionet.nsc.ru Author Onishko, Vladimir V. 0000-0002-6469-6778 Moscow Zoo, Department of Herpetology, Bolshaya Gruzinskaya Str. 1, Moscow 123242 Russia. wervolf999@yandex.ru Author Ilyina, Elena V. 0000-0002-5426-4015 Precaspian Institute of Biological Resources of the Daghestan Federal Research Centre of the Russian Academy of Sciences, Dagestanskiy State Nature Reserve, Gagarina Street 120, Makhachkala, Republic of Dagestan, Russia. carabus@list.ru Author Chepurnov, Grigory Yu. 0009-0000-8268-0289 Institute of Cytology & Genetics SB RAS, Acad. Lavrentyev ave. 10, Novosibirsk, 630090, Russia. & Institute of Molecular and Cellular Biology SB RAS, Acad. Lavrentyev ave. 8 / 2, Novosibirsk, 630090, Russia. grigory.tchepurnov@yandex.ru Author Blinov, Alexander G. 0000-0002-4971-6312 Institute of Cytology & Genetics SB RAS, Acad. Lavrentyev ave. 10, Novosibirsk, 630090, Russia. & Institute of Molecular and Cellular Biology SB RAS, Acad. Lavrentyev ave. 8 / 2, Novosibirsk, 630090, Russia. blinov@bionet.nsc.ru text Zootaxa 2024 2024-06-18 5471 2 151 190 http://dx.doi.org/10.11646/zootaxa.5471.2.1 journal article 298715 10.11646/zootaxa.5471.2.1 3a469638-dc21-45a3-80f6-cb307fbf5941 1175-5326 12189904 BAA047F4-2D65-4E52-8798-D426E3B26DA1 Coenagrion ornatum Skvortsov (2010) and Skvortsov & Snegovaya (2015) raised concern about reality of the species Coenagrion vanbrinkae Lohmann, 1993 (originally proposed in an incorrect grammatical gender, as C. vanbrinki , see van Tol (1994)) and its presence in the Caucasus and Transcaucasia. This species was described from Iran and the eastern Turkey as differing from C. ornatum with just one seemingly distinct character: the male cerci diverged in the dorsal view rather than almost contacting with their tips, other characters mentioned in the original description ( Lohmann 1993 ) being negligible. Kosterin & Ahmadi (2018) analysed this character from the regions of Central Iran close to the type locality (Dorud) and found both versions of the cerci position in subequal frequencies. They concluded that this is a matter of position of a movable appendages rather than their structure and so, following Boudot & Kulijer (2015) , considered C. vanbrinkae as a pure junior synonym of C. ornatum . This treatment is adopted in the World Odonata List ( Paulson et al. 2024 ) . Skvortsov & Snegovaya (2015: 36) claimed that “a more detailed comparison” of the Azerbaijanian specimens under scanning electron microscope “shows that all the specimens are intermediate” between ornatum and vanbrinkae . This agrees with a continuously variable degree of the cerci divergence in our specimens from Dagestan ( Fig. 10 ), that is in favour of synonymy of C. ornatum and C. vanbrinkae . Curiously and in contrast to the above, our specimens from Central Iran could be classified to two distinct classes of broadly divergent versus almost not diverged cerci ( Kosterin & Ahmadi 2018 ). There are some unpublished data hinting that specimen series of C. ornatum from the same region collected by different persons may strongly differ in the proportion of males with diverged vs non-diverged cerci, which may be interpreted so that the position of male cerci may depend on the method of killing of voucher specimens.