Some rare damselflies and dragonflies (Odonata: Zygoptera and Anisoptera) in Ukraine: new records, notes on distribu- tion, and habitat preferences

New records of 11 rare species of damselflies and dragonflies (Calopteryx virgo, Lestes macrostigma, Nehalennia speciosa, Coenagrion scitulum, Ophiogomphus cecilia, Lindenia tetraphylla, Cordulegaster boltonii, Somatochlora arctica, Leucorrhinia albifrons, Leucorrhinia caudalis, and Selysiothemis nigra) within Ukraine are given. Habitats and distribution of species within the country are briefly discussed. Breeding sites of C. boltonii within Ukraine is found for the first time and confirmed with larval material. Somatochlora arctica is recommended for inclusion in the next edition of the Red Data Book of Ukraine.


INTRODUCTION
Damselflies and dragonflies (Odonata: Zygoptera & Anisoptera) belong to a small order in the fauna of Ukraine; it comprises only 78 species (Gorb et al. 2000;Tytar 2007;Savchuk & Karolinskiy 2013;Bernard & Daraż 2015). Despite the rather scarce fauna, distribution of many species is poorly and unevenly studied. Some regions have a lot of information published on Odonata, while in other regions even the data on species compositions are fragmented. Consequently, the distribution and habitat preferences of rare species within Ukraine are still understudied and cannot be used for analysis of species' vulnerability.
This paper is aimed to publish new records of some rare Odonata in Ukraine; some of these species are included in the third edition of the Red Data Book of Ukraine (2009) or recommended to be included in the next edition of this book by other colleagues or by me.

MATERIAL AND METHODS
Collected material (imagoes, exuviae and larvae) is deposited in author's collection in the National Museum of Natural History of the National Academy of Sciences of Ukraine (further NMNH NASU). The larvae, exuviae, and imagoes are deposited in 85-95 % EtOH and pinned. Photographs of specimens were taken by author using Canon SX30SI (Images 1A, 1B, 6A, 7A, 10H) and Leica Z16 APO equipped with Leica DFC450 Digital Camera (Images 1C-E, 2A-D, 3A-C, 4A-C, 5A-F, 6B, 6C, 7B-F, 8A, 8B, 9A-D, 10A-D, I-K) in the I.I. Schmalhausen Institute of Zoology of the National Academy of Sciences of Ukraine, and subsequently processed with LAS Core 3.8 and Adobe Photoshop™ CS5 software. Photographs of some specimens and/or their distinguishing characters are given to confirm identification.
I registered new populations of the species within the highest part of Donetsk elevated area (Donetsk Ridge) (Image 1A-G) at the upper parts of Bulavina, Ol'hova and Khrustal'na Rivers. The rivers in these sections are covered with forest and represent rhithral or epipotamal zones with current velocity up to 0.7m/s (in some places absent, on rapids -up to 1.5m/s). The detailed description of the investigated section of Bulavina River, change of water temperature during the year and photos of habitats are given in previous articles (Martynov & Godunko 2013;Martynov 2013Martynov , 2014a.
Calopteryx virgo is relatively common only at Bulavina River. Imagoes were mainly recorded on small glades, up to 5-8 specimens at the same time; solitary specimens were regularly observed in shady forests and on water surface; larvae were registered at places with moderate current velocity, mainly near the banks on roots of black alder. Recorded population of C. virgo is the biggest known within southeastern Ukraine. Material from Ol'hova and Khrustal'na Rivers were sampled several times, and only some specimens of the species were registered. Moreover, many similar waterbodies of Donetsk Ridge can be considered as potential habitats for the species; they should be investigated in future.

Coenagrion scitulum (Rambur, 1842)
This is a rare species in Ukraine; known from a few sites within Crimea, Odesa, Mykolaiv, Kherson, Chernihiv and Donetsk Regions (Polischuk 1964(Polischuk , 1974Sheshurak & Padalko 1996;Dyatlova 2006;Khrokalo & Prokopov 2009;Martynov & Martynov 2009;Stepoviy 2018). According to Pavlyuk (1973), the record of C. scitulum larvae from Kherson Region is doubtful; record of the species from Chernihiv Region should also be considered as doubtful. Here, I present a new record of the species within Donetsk Region; one imago was recorded on the bank of small lentic seasonal waterbody at Belosarayskaya spit (Image 3A-D). This record without information on concrete locality coordinates and data of collecting was mentioned in Martynov (2010b).

Nehalennia speciosa (Charpentier, 1840)
This species is the smallest odonate among European taxa. Nehalennia speciosa is locally distributed within all Europe and locally extirpated in many locations previously recorded as habitats (Bernard & Wildermuth 2005;Dijkstra 2006). Known few habitats of the species in Ukraine are situated within northern, western and eastern regions mainly; in most southern locations of the country (Crimea, Odesa, and Kherson Regions) the species is considered as locally extirpated (Polischuk 1974, Gorb et al. 2000Khrokalo & Nazarov 2008;Khrokalo & Prokopov 2009;Tytar 2009Tytar , 2019Dyatlova & Kalkman 2008;Karolinskiy 2013;etc.). Nehalennia speciosa was recommended for being included to the Red Data Book of Ukraine by Khrokalo (2005).
New breeding sites of N. speciosa were found in Rivne Region within Rivnenskyi Nature Reserve (Image 4A-E). The species inhabits waterbodies on sphagnum bogs (marshes) in all locations, except for two places where species inhabits deep lakes (Bile Lake and Black Lake) with banks overgrown with wide dense cushions of floating sphagnum. Depth of the lakes near the floating banks is about 2-3 m. Also, species was registered at small, relatively shallow natural waterbodies (area up to 20m 2 ; depth -about 0.5m) on sphagnum bog and at old artificial waterbodies (area -up to 150m 2 ; depthup to 1.2m) on the same kind of bog. Moreover, the biggest number of specimens was recorded at the old J TT artificial waterbodies (up to 25-30 specimens at 10 m of a bank length); in all other points the number of specimens was much lower. It should be noted, that that due to significant age these artificial waterbodies didn't differ from the natural waterbodies in water parameters, vegetation, and appearance. Diapason of some parameters of waterbodies in collecting places was water hardness 9-16 ppm, pH 5.
I recorded the species in Horyn', Stvyga, Styr, and Sluch Rivers within Rivne Region, in the basin of Prypiat River (Image 5A-H). Larvae of the species were collected from bottom at microhabitats with sand in the rivers, sometimes with small stones or/and pieces of bog iron ore (in some cases bottom was just slightly silted), current velocity was about 0.2-0.3 m/s. These localities seem to be the most typical habitat for the species (Dijkstra 2006). The diapason of some parameters of waterbodies at collection sites were water hardness 43-210 ppm, pH 6.5-8.9. In my opinion, within Donetsk Region (Martynov 2014b). I registered imagoes of the species in a few places within southern Zaporizhzhia. Imagoes were recorded on steppe areas near Malyi Utluk River and Molochnyi Estuary, where they hunted for different insects (Image 6A-E). Lindenia tetraphylla was abundant in the region, up to seven specimens were registered on some areas. Larvae of the species are associated with lakes and slow-flowing rivers, therefore, the development of L. tetraphylla in regional waterbodies (e.g., Malyi Utluk River, Tashchenak

Cordulegaster boltonii (Donovan, 1807)
The species is very rare in Ukraine and is included in  Kyselyuk et al. (2018) is considered doubtful because of the similarity of two species mentioned above and available data on distribution of species within Ukraine. Unfortunately, the specimen mentioned in the article is absent in the collection of the authors (Slobodyan O.M., pers. comm. 2020). According to Gorb (1991), only known records of C. boltonii larvae from the territory of Ukraine (Tal' River, Kyiv Region) (Trylis 1988) are unreliable because the material was lost. The investigations carried out at Tal' River in the vicinity of Rudnya-Shpylivs'ka village in January 2020 did not reveal any larvae of Cordulegaster; further investigations of the river will be continued. I recorded larvae of C. boltonii in Mohylivka River within Zhytomyr Region (Image 7A-G). This is the first confirmed record of the species' larvae within country. Investigated section of the river had riparian vegetation, and was shallow (depth up to 0.5m, but mainly about 0.2m), with numerous small bays; with current velocity up to 0.2-0.3 m/s, but mainly with standing water; sandy bottom was covered with detritus, leaf litter and branches; the bottom was presented with only sand in some sections of the main stream. Larvae were collected in bays, from a thick layer of detritus. The additional parameters of waterbodies in collecting places measured during the sampling were-water temperature 16°C, water hardness 47ppm, pH 8.5.

Somatochlora arctica (Zetterstedt, 1840)
This species is very rare within Ukraine. For a long time, it was known only by almost 100-year old records from Zhytomyr Region (Gorb et al. 2000). Only in 2006 and 2007 this species was recorded within Poliskyi and Rivnenskyi Nature Reserves (Zhytomyr and Rivne Regions) (Khrokalo & Nazarov 2008;Martynov & Martynov 2009). Somatochlora arctica was known by a few imagoes only from both reserves, but the development of the species at the swamps of the protected areas is doubtless. Previously, the species was recorded from two sites within Rivnenskyi Nature Reserve in Bil's'k forestry in 2006 (Martynov & Martynov 2009) Martynov A.V., 26.v.2017. One imago, Ukraine, Rivne Region, vicinity of Rudka village, black-eared swamp, tributary of Berezyna River, 51. 486267N & 25.709517E, Martynov A.V., 02.viii.2017.
For now, Rivnenskyi Nature Reserve is the territory with the highest number of records of S. arctica within Ukraine. The main reason of species' rarity and local distribution within Ukraine is the disappearance of waterbodies suitable for species' development, namely sphagnum and sphagnum-sedge bogs. The disappearance of these bogs is caused by-(i) ameliorative measures; (ii) decrease in the annual rainfall in Polissia, which leads to the drying up of bogs; and (iii) large volumes of illegal amber production in the region, which leads to the complete destruction of the necessary microhabitats and/or waterbodies suitable for the development of S. arctica. Therefore, I think that this species should be considered for inclusion in the next edition of the Red Data Book of Ukraine.
I had found imagoes (one of the records is a copulated pair) of the species at Bile Lake on sphagnum bog in vicinity of Rivnenskyi Nature Reserve (Image 9A-D). Most likely, the larvae of L. albifrons had been developing here. The detailed description of the lake is given above. The species was not registered at any other neighboring waterbody.
Thus, a lot of rare and/or red-listed in Ukraine Odonata species are registered at Bile Lake and neighboring Black Lake (e.g. N. speciosa, A. imperator, S. arctica and L. albifrons), therefore, these lakes are recommended to be included to the territory of Bil's'ke forestry of Rivnenskyi Nature Reserve.
I had recorded imagoes of S. nigra at few steppe areas near Malyi Utluk River and Molochnyi Estuary (Zaporizhzhia Region) (Image 10G-K). In some places I recorded up to eight specimens on 300m of a route. As in case of L. tetraphylla, larvae of S. nigra are perspective to be found in Malyi Utluk River, Tashchenak River, and Utlyukskyi Estuary. Also one male imago was registered at steppe area near Syvash Lake in Kherson Region.
In my opinion, the distribution of species in Ukraine is now wider and the places of development are denser than was previously known; distribution of S. nigra in Ukraine probably covers all coastal areas of Black and Azov Seas in Odesa, Mykolaiv, Kherson, Zaporizhzhia and Donetsk Regions, and Crimea.