Kosterin, O.E. 1999. Dragonflies (Odonata) of the Daurskii State Nature Reserve and its surroundings. - In: Dubatolov V. V. et al., eds. Nasekomye Daurii i sopredel'nykh territorii. Sbornik nauchnykh trudov. Vypusk 2. [Insects of Dauria and Adjacent Territories. Issue 2]. - Novosibirsk - Pp. 5-40 (in Russian).

Original Russian version is HERE

Hyperlinks are added to the photos made while these studies (not published in the paper).

O.E. Kosterin

Institute of Cytology and Genetics of Siberian Division of Russian Academy of Sciences,

Academician Lavrentiev avenue 10, Novosibirsk 630090 RUSSIA.

ABSTRACT. Dragonflies of the Daurskii State Biosphaera Nature Reserve and the surroundings of the village Nizhnii Tsasuchei, where its office is situated, were observed and collected in 1995-1997. An annotated list of species contains a full reference to the specimens collected, notes on biotope preferences and relative abundance of species, for some species systematic notes and data on variation are given. Earlier 17 species were reported for this territory, now their number have risen to 31. Among them the Manshurian species Cercion v-nigrum Needh. and Anisogomphus maackii Selys, thought to range westwards up to Blagoveshchensk only, were found out. Anax parthenope Selys and Pantala flavescens Fabr. proved to be present in Transbaikalia. A Chinese/Mongolian species Ophiogomphus spinicornis Selys is for the first time reliably reported for the Russian territory.

Until recently the dragonfly fauna of SE Transbaikalia was insufficiently known since this territory was not visited by B. F. Belyshev, a foundator of Siberian odonatology who undertook numerous expeditions all over Siberia. In 1996 a special paper by Gorb et al. (1996) was issued, which was devoted to the dragonfly fauna of the Daurskii State Nature Reserve and the surroundings of the village Nizhnii Tsasuchei (where the office of the reserve is situated). There were reported 17 species, including Aeshna serrata Hagen for the first time for Transbaikalia. However, this paper was based on materials collected by non-odonatologists. In 1995-1997 I had a fortunate opportunity to take part in investigations on the entomofauna of this reserve carried out by the Institute of Systematics and Ecology of Animals, the Siberian Division of the Russian Academy of Sciences, in 1995 in cooperation with the Ecological Club of Novosibirsk State University. Together with me my colleagues O.G. Berezina and V.V. Dubatolov took an active part in collecting the materials, some small but interesting collections were kindly provided by I.I. Lyubechanskii, A.V. Korolyuk, and V.A. Brinikh. Besides, some materials were taken into account collected by E. Maksimenko in 1989 and identified by E.I. Malikova, who kindly communicated me their listing. In August 1996 V.V. Dubatolov collected some dragonflies in the southern part of the depression of Torei Lakes on the territory of the Mongol Daguur Nature Reservation, Mongolia.

As a result, 1298 specimens of 31 species of dragonflies and damseflies were collected. Among them two Manshurian species, Cercion v-nigrum and Anisogomphus maackii, were unexpectedly found which were so far known not westerly of Blagoveshchensk (Malikova, 1995, 1997à). Besides, the presence in Transbaikalia was proved of two southern species, Anax parthenope and Pantala flavescens, while a Chinese-Mongolian species Ophiogomphus spinicornis was for the first time reliably reported for the territory of Russia.

The region studied

The name Dauria or Dahuria is usually applied to all the steppen regions of Transbaikalia and adjacent regions of North China and East Mongolia. The Daurskii Biosphaera State Nature Reserve is situated in the southern Chita Province, on the territory of the Ononskii and Borzinskii Districts, and is a reserve of a cluster type uniting a number of protected territories of different status (Fig.1). It was founded in 1987 mostly for protection of avifauna of the Torei Lakes, first of all - of several species of cranes, and of persisted areas of virgin steppe. The reserve comprises a Russian part of the Dauria International Nature Reserve, together with the Mongol Daguur Reserve (Mongolia) and the Dalainor Reserve (China). Within the Daurskii Reserve a regime of strict protection (category I in IUCN [International Union for Conservation of Nature and Natural Resources] nomenclature) is given to the aquatory of Lake Barun-Torei (except for its small parts at the village Kulusutai, the Khotogor Bay, and the SE corner), patches of reed thickets at the Uldza River delta and steppes along the Russian/Mongolian border at the southern banks of this lake (where the breeding places of many bird species and the zeren or Mongolian gazelle (Procapra gutturosa Pallas) are protected), three small areas on the elevation at the northern bank of Lake Zun-Torei, and a small fragment of a pine forest between the Torei Lakes and the Onon River (in total about 44 752 hectares). The buffer zone regime (totally 112 thousand hectares) is given to the lands around the Torei Lakes and the coastal part of the aquatory of Lake Zun-Torei. The aquatory of the Torei Lakes and adjacent lands, including the Reserve territory, has a buffer zone regime as being the Torei Lakes wetland of international importance (within Ramsar convention), with a regime of a buffer zone (but less strict). 57.9 thousand hectares south of the Onon River are occupied by the zakaznik (i.e. a protected area of category III-IV of IUCN nomenclature) of a federal importance Tsasucheiskii Bor. Besides, a regime of a Nature monument is applied to the rocky ridges of the Adon-Chelon elevation at the mountain Tsagan-Obo, its transition to a strictly protected cluster is under consideration. The office of the reserve is in the village Nizhnii Tsasuchei on the Onon River, a center of the Ononskii District.

Such a complicated structure of the Daurskii Reserve makes it not reasonable to study the fauna of the strictly protected territories as such. It is more convenient to consider the fauna of contiguous and homogenous natural areas containing the protected territories. They are the Torei Lakes depression, the Tsasucheiskii pine forest, the Onon River valley and the Adon-Chelon elevation. These areas differ much for their natural conditions. On each of them the dragonflies were collected in a number of sites shown on Fig. 1.

The region studied is in general situated between 49⁰40' and 50⁰30' n. lat. and 115⁰ and 116⁰. e. lon. on the Uldza-Torei Plain, which is a northern projection of the raised plains of Central Asia justing out into the mountain belt of South Siberia. It has a so-called Gobi-type relief characterized by an intricate alternation of hills and small ridges and intermontane depressions of various sizes and shape. Most part of this region has no outflow, numerous salt and brackish lakes being scattered over. Besides, it is crossed by a major river Onon (the Pacific basin). The climate is of an arid continental type (with the annual precipitation about 200 mm), with a weak influence of the Pacific monsoon (Suslov, 1954). The winter is practically snowless, the majority of precipitation (up to 70%) falling in the summer, partly due to the monsoon. In a geobotanical respect the territory (except for the Adon-Chelon massif) belongs to the Central Asian (Daur-Mongolian) Subregion of the Steppen Region of Eurasia, mostly to the Mongolian Steppen Province, East-Mongolian Subprovince (Lavrenko et al., 1991).

At present the two Torei Lakes, Barun-Torei and Zun-Torei (their altitude being 597 m above sea level), connected with the straight Utycha, are large water bodies with a non-transparent milky-white coloured slightly mineralized water of a soda type (calcium and magnium carbonates at concentration about 1 g/l at present), practically lacking macrophytes. These lakes have not so regular a cyclicity with a period of about 30 years, on each cycle they disappear turning into salines. Now the lakes enjoy nearly a maximum filling and minimum mineralization. The lakes are fed by the waters of the Uldza or Uldz-Gol River flowing from the south. It is this river from which recolonization with aquatic invertebrates and fish (Carassius auratus gibelio (Bloch), Phoxinus, Misgurnus anguillicaudatus (Cantor)) most probably takes place when the lakes reappear. The SW bank of Lake Barun-Torei at the cordon Bulum-Khuduk is boggy and is covered with wide reed thickets, other banks of the Torei Lakes are mostly hard and clear, locally rimmed with narrow thickets of the sedge and (a local remarkable!) Iris lactea Pallas. (The plant species nomenclature follows (Flora Central'noi Sibiri, 1979) and (Flora Sibiri, 1987-1998)). The lowest lands at the banks are covered with a slightly salinated phytocenoses with large tussocks of the grass Achnatherum splendens (Trin.) Nevski (=Lasiagrostis splendens (Trin.) Kunth.), mostly the surroundings of the lakes are occupied with zonal communities of true steppes and dry steppes (with Stipa krylovii Roshev., Cleistogenes squarrosa (Trin.) Keng, Koeleria cristata (L.) Pers., Festuca dahurica (St.-Yves) Krecz. et Bobrov, Leymus chinensis (Trin.) Tzvelev, Carex pediformis C.A. Meyer, Carex duriuscula C.A. Meyer, in different combinations, among the dominants). Up to middle or late June the steppe is practically lifeless, with the summer rains it becomes green and covered with numerous flowers. The blossom of the steppe, with changing aspects, continues to late August.

There is a hilly ridge along the northern bank of Lake Zun-Torei, with a gentle northern slopes and rather steep southern ones. Major hills of this ridge are called, from west to east, Chikhalan, Gydyrgun (746 m above sea level), Kuku-Khadan (745 m), Khodonyata (Erel'dzhin) covered with a dry steppe, with bush (Spiraea pubescens Turcz., Ulmus macrocarpa Hance, Ribes diacanthum Pallas.) and even tree (groups of Ulmus pumila L.) vegetation on rocks and in ravines of the southern slope.

10 km west of the SW corner of Lake Barun-Torei there are two small lakes, Nizhnii Mukei (on the Russian territory) and Ded Mukei Nur (on the Mongolian territory). Their water is strongly mineralized (chlorides and sulfates at concentrations about 17 g/l), although some freshwater sources leak into the lake at the bottom (V. Obyazov, personal communication). Such a high mineralization, however, is accompanied with a great abundance of invertebrates (Copepoda, Corixidae, larvae of Dytiscidae and Enallagma cyathigerum Charp.).

The so-called Tsasucheiskii Bor is an unique forest extending for 40 km longitudinally and 50 latitudinally southwards of the Onon River. It is formed by a peculiar form of the pine tree, Pinus sylvestris krylovii (Serg. et Kondr.) Busik (= Pinus krylovii Serg. et Kondr.), adapted for an extreme arid environment. It has a short and stout trunk, dense and wide crown with living branches along the entire trunk from its very base, long needles. Its stands are rather sparse so that there is almost intact steppen vegetation in the ground layer. This pine is offensive on the steppe, the forest age being no more than 150 years. It is thought that this pine subspecies had arisen not earlier than 250 years ago on the other side of the Onon River, in the stow Tsarik-Narasun or near, then it spread southwards in accordance with predominating winds. Unfortunately, in the central part of Tsasucheiskii Bor a lot of the common pine-trees were planted by man. Due to self-sowing without thinning out, they formed very dense stands without ground layer. The common pine now is intensively intragressing with the Krylov's pine so contaminating its unique gene fund highly valuable for forestation of arid lands. It is such a dense part of the forest, formed mostly by both Krylov's pine and the common pine, 18 km SW of the village Nizhnii Tsasuchei, where a small mesotrophic Lake Betevken is situated. It is surrounded by a large meadow steppe opening, on the same opening there is another smaller and very shallow lake Malyi Betevken. In Tsasucheiskii Bor dragonflies were collected on these lakes and in an open part of the forest along the right board of the Onon River valley.

The Onon River flows from the Kentei Mts., on its banks Genghiz-Khan was born. The Onon valley was studied within a section from 15 km upstream to 2 km downstream of the village Nizhnii Tsasuchei. The Onon left bank belongs to Aginskii Buryat National District. The valley is mostly very wide (up to 7 km), its left board has rocky cliffs, the right one is also clear cut but has scarce rock outcrops. There are hills Bol'shoi Batur and Malyi Batur (758 and 727 m, respectively) on the left bank and Kuruntei on the right bank. These hills, as well as the entire left board of the valley, are covered with the Daurian meadow steppes with the dominance of Filifolium sibiricum (L.) Kitam, Festuca dahurica, Leymus chinensis, Carex pediformis. They are rich in plant species, especially herbs. The petrophyte variants of steppen communities are also well expressed on the hills. The rocky cliffs of the valley left board are covered with bush thickets of Ulmus macrocarpa, Ulmus pumila, Armeniaca sibirica (L.) Lam. An open pure stand of Pinus sylvestris krylovii, being the northern edge of Tsasucheiskii Bor, covers the right board of the Onon valley.

The Onon is a large and fast river with a clear water and a pebble bed. Its level is very unstable, a powerful flood occurs in middle summer, but its dates are greatly varying yearly. The Onon bed at the village Nizhnii Tsasuchei is at the altitude of 643 m above sea level. The Onon forms many arms, some of which dry up or are fed with cold ground water when the river level is low. At the village Nizhnii Tsasuchei the Onon has two stable arms, Staryi Onon, the left, and Novyi Onon, the right, with the Kharganai island between them. The floodlands are covered with meadow vegetation or tussock bogs, in the middle summer mostly inundated, and willow thickets. On the meadow areas the bushes of Rosa davurica Pall., Spiraea salicifolia L. and small trees Malus baccata (L.) Borkh. are common. On the right bank 3 km upstream of Nizhnii Tsasuchei there is a grove of Ulmus pumila trees. On the left bank there are open riparian woods of Populus suaveolens Fischer. On a widened section of the right bank floodland above the embankment of the bridge on the highway Aginskoe - Nizhnii Tsasuchei (7 km upstream of the latter) there are several chains of shallow eutrophic mortlakes with a rich water vegetation and invertebrate fauna. Among them a small lake Kudon is remarkable, situated 12 km W of Nizhnii Tsasuchei, near the right board of the valley. These mortlakes seem to have most diverse odonatofauna among all the water bodies studied in this region.

The elevation of Adon-Chelon is a part of the mountain massif of Sherlovaya Gora, it is situated 65 km east of Nizhnii Tsasuchei. Its main summit is the mountain Tsagan-Obo (985 m above sea level, 10 km E of the village Adon-Chelon). This elevation is composed of a number of gentle ridges crowned with impressive granite rocks (zeugens). The elevation is covered with luxuriant meadow steppes of a Daurian type, with participation of numerous herb species and domination of Filifolium sibiricum, Festuca dahurica, Leymus chinensis, Carex pediformis. (These meadow steppes are considered to be to some extent analogous to North American prairies). There are thickets of Spiraea aquilegifolia Pall., Sorbaria sorbifolia (L.) A. Br., Ulmus macrocarpa bushes and sparse trees of Ulmus pumila at the rocks. Small but very dense groves of the asp and/or birch are situated at northern sides of the largest zeugens. In a geobotanical respect this massif lies within the Khangai-Daurian Mountain Forest-Steppe Province, Nerchinsk-Ononian (Daurian sensu stricto) Subprovince (Lavrenko et al., 1991)

Between the Adon-Chelon massif and the village Nizhnii Tsasuchei a small winding rivulet Borzya flows in a wide boggy valley.

Materials collecting

For the sake of convenience of referring the materials collected the main collection sites (see Fig. 1) are designated conventionally with one or two words explained below:

1. Tsasuchei: the Novyi Onon arm right bank within 2 km downstream of Nizhnii Tsasuchei.

2. Bor: open stand of pine trees of Tsasucheiskii Bor within few km south and west of Nizhnii Tsasuchei, not on the Onon bank, mostly along the highway.

3. Right Bank: the right bank floodland and terrace (the latter is covered with open pine forest) of the Novyi Onon arm between the village Verkhnii Tsasuchei (adjacent to Nizhnii Tsasuchei from the west) and the bridge.

4. Bridge: stagnant mortlakes of the Onon right bank floodland just upstream of the embankment of the highway Aginskoe-Nizhnii Tsasuchei, 7 km W of the latter. During the flood of the Onon River in early June 1995 all these water bodies became arms of the Onon.

5. Upper Floodland: water bodies of the same type between the bridge and the hill Kuruntei (15 km W of Nizhnii Tsasuchei). Most part of the collections were made on a small Lake Kudon 12 km W of Nizhnii Tsasuchei.

6. Left Bank: the Onon River left bank 5-10 km upstream of Nizhnii Tsasuchei, including the hill Malyi Batur environs. (This is the territory of Aginskii Buryat Autonomous District.)

7. Betevken: Lake Betevken in the Tsasucheiskii Bor pine forest 18 km SW of Nizhnii Tsasuchei.

8. Malyi Betevken: a small very shallow lake about 1 km of Lake Betevken.

9. Borzya: the Borzya Rivulet valley 16 km upstream of its mouth.

10. Adon-Chelon: an elevation, with the mountain Tsagan-Obo, 10-15 km NNW of the village Tasyrkhoi, west of the settlement Sherlovaya Gora.

11. Mukei: Lake Nizhnii Mukei on the Russian/Mongolian border 10 km W of the SW corner of Lake Barun-Torei.

12. Uglovoe: a small lake SE of the SE corner of Lake Barun-Torei.

13. Bulum: the SW bank of Lake Barun-Torei, at the cordon Bulum-Khuduk.

14. Nipsei: the surroundings of the border service light house Nipsei south of the cordon Bulum-Khuduk at the SW corner of Lake Barun-Torei

15. Borokholoi: the Borokholoi Rivulet falling into the Torei Lakes at the straight Utycha.

16. Utycha: the straight Utycha between the Torei Lakes.

17. Teli: the banks of the isthmus between the Torei Lakes at the hill Teli and a small bay Khotogor.

18. Chikhalan: the NW bank of Lake Zun-Torei at the foot of the hill Chikhalan.

19. Kuku-Khadan: the southern slope of the hill Kuku-Khadan and the adjacent NE bank of Lake Zun-Torei.

20. Khodonyata: surroundings of the Khodonyata (Erel'dzhin) hill at the BE bank of Lake Zun-Torei

21. Solovyovsk: the surroundings of the settlement and railway station Solovyovsk.

The following collecting sites are situated at the Torei Lakes on the territory of the Eastern Aimak of Mongolian People's Republic:

22. Erentsav: a steppe 2 km S of the railway station Erentsav.

23. Chulun-Khorot: 4 km of the village Chulun-Khorot, SW of Lake Barun-Torei.

24. Duro-Nur: Lake Duro-Nur on the Uldz-Gol River.

25. Shudu-Gol: the loop of the Shudu-Gol River 25-28 km S of the station Erentsav.

26. Khukh-Nur: the western bank of Lake Khukh-Nur, south of its bay.

27. Eltrud: the mountain Eltrud 10 km ESE of the Duchiyn Gol River mouth.

28. Avdar-Tolgoi: the mountain Avdar-Tolgoi, at the Duchiyn Gol River mouth.

Fig. 1. A map of the region studied. Locations are numberred as follows:1, Tsasuchei; 2, Bor; 3, Right Bank; 4, Bridge; 5, Upper Floodland; 6, Left Bank; 7, Betevken; 8, Malyi Betevken; 9, Borzya; 10, Adon-Chelon; 11, Mukei; 12, Nipsei; 13, Bulum; 14, Uglovoe; 15, Borokholoi; 16, Utycha; 17, Teli; 18, Chikhalan; 19, Kuku-Khadan; 20, Khodonyata; 21, Solovyovsk; 22, Erentsav; 23, Chulun-Khorot; 24, Duro-Nur; 25, Shudu-Gol; 26, Khukh Nur; 27, Eltrud; 28, Avdar-Tolgoi. For explanations see the text.

Below enumerated are the dates of collecting and collectors, the number of specimens collected are given in brackets.

1995: June 14 - Kuku-Khadan (10); June 15 - Mukei (9), Nipsei (1) (V. Dubatolov, I. Lyubechanskii); June 18 - Tsasuchei (6), Bridge (41) (O. Kosterin, O. Berezina, I. Lyubechanskii); June 19-21 - Adon-Chelon (28); June 21 - Borzya (78) (O. Kosterin, O. Berezina, I. Lyubechanskii, V. Smirnova); June 23 - Bulum (70); June 24 - Mukei (3), Kuku-Khadan (23); June 25 - Teli (19) (O. Kosterin, O. Berezina); June 25 - Utycha (3) (I. Lyubechanskii); June 25 - Betevken (43); June 26 - Malyi Betevken (61) (O. Kosterin, O. Berezina, I. Lyubechanskii); June 28 - Tsasuchei (9); June 29 - Bor (1), Right Bank (2); June 30 - Bor (1), Bridge (46); July 1 - Right Bank (1), Left Bank (1); July 2 - Mukei (29); July 3 - Bulum (15); July 5 - Right Bank (14), Bridge (2), Left Bank (2) (O. Kosterin, O. Berezina); July 21 and 24 - Kuku-Khadan (11); July 27 - Teli (2); August 7 and 9 - the southern bank of Lake Zun-Torei; August 11 - Adon-Chelon (9) (A. Korolyuk); August 16 - Tsasuchei (14); August 17 - Right Bank (14) and Left Bank (2); August 17-18 - Solovyovsk (4); August 18-19 - Utycha (1); August 19 - Teli (7); August 22 - Bridge (5), Left Bank (1); August 23 - Bulum (3) August 24 - Uglovoe (7), Mukei (3) (V. Dubatolov).

1996: June 29 - Teli (5); June 30 - Right Bank (5), Bridge (42); July 1 - Bridge (2); July 2 - Right Bank (13), Upper Floodland (25); July 3 - Bridge (2); July 4 - Betevken (5); July 5 - Upper Floodland (41); July 7 - Bulum (1); Mukei (9); July 8 - Borzya (25), Adon-Chelon (3); July 9 - Adon-Chelon (10); July 11 - Left Bank (25); July 12 - Chikhalan (26); July 14 - Bor (17); July 15 - Right Bank (6), Bridge (5), Upper Floodland (41); July 16 - Right Bank (1), Upper Floodland (24) (O. Kosterin); July 18 - Khodonyata (3); July 20 - Tsasuchei (3), Bor (3); July 22 - Erentsav (2), Shudu-Gol (6); July 23 - Eltrud (3), Khukh-Nur (3), Duro-Nur (17); July 24 - Erentsav (4), Avdar-Tolgoi (2); July 25 - Chulun-Khorot (1) (V.V. Dubatolov); July 29 - Bor (2) (V.A. Brinikh); July 31 - Right Bank (5); August 1 - Bor (2); August 2 - Mukei (6); August 3 - Bulum (4), Right Bank (3); August 5 - Bor (4); August 15 - Khodonyata (5); August 16 - Tsasuchei (2); August 18 - Right Bank (10), Left Bank (3); August 21 - Right Bank (2); August 22 - Bor (9); August 23 - Right Bank (3), Upper Floodland (10) (V.V. Dubatolov)

1997: July 16 - Right Bank (8), Bridge (3); July 17 - Right Bank (4), Bridge (7), Upper Floodland (5); July 18 - Right Bank (1), Bridge (1); Upper Floodland (47); July 19 - Right Bank (13), Upper Floodland (1); July 20 - Bor (5); August 9 - Kuku-Khadan (3), Tsasuchei (3), Bor (1); August 10 - Bor (29), Right Bank (4), Upper Floodland (32) (O. Kosterin, O. Berezina).

If there were other collectors they will be specified below especially.

Annotated list of species.

Asterisks (*) stand for the species being reported for Transbaikalia for the first time. Letters m and f designate males and females, respectively. Figures in brackets at the end of the "Materials" paragraph designate the total number of specimens collected. Collections made in 1995 more or less reflect relative abundance of species within suborders; collections of 1996 and 1997 were made selectively. Collections for the second half of July and August in 1995 and 1996 were made by non-odonatologists and not systematically and so do not reflect the dragonfly aspects adequately. In some cases when variation is characterized the number of specimens mentioned is less than their total number since some materials were sent out to other odonatologists before analysis.

Familia LESTIDAE

1. Lestes dryas Kirby, 1890

Materials: Bridge: 5.VII 95 - 1f; Upper Floodland: 19.VII 97 - 1m; Bulum: 3.VII 95 - 1m; "Torei Lakes": 13.VIII 89 - 1m, 1f (E. Maksimenko). (5).

Rather a rare species. Noteworthy, it was not found on Lake Kudon, where only Lestes sponsa occurred, but both species were collected on a dried up mortlake few km of it. In Siberia L. dryas is as a rule found on diverse water bodies, including very small ones, while L. sponsa usually inhabits larger ones but attain a greater abundance (Belyshev, 1973; Kosterin, 1996). However, both species are not numerous in the Onon valley.

2. Lestes sponsa (Hansemann, 1823)

Gorb et al., 1996.

Materials: Right Bank: 19.VII 97 - 1m, 1f; Bridge: 15.VII 96 - 1f; Upper Floodland: 23.VIII 96 - 6m, 2f, 18.VII 97 - 3m, 10.VIII.97 - 5m, 4f; Mukei (a rivulet falling into it): 2.VIII 96 - 1m, 1f; "the southern end of Zun-Torei": 7.VIII 95 - 2m, 3f; "Torei Lakes": 13.VIII 89 - 10m, 1f (E. Maksimenko); Borokholoi: 13.VIII 89 - 3m, 1f (E. Maksimenko); Eltrud: 23.VII 96 - 1m, 1f. (47)

A teneral female collected on August 15 had a distinctly yellow occiput, with a sharp border of a yellow and bronze colours. Such a colouration of the occiput is characteristic for Lestes barbarus (Fabricius, 1798), L. japonicus Selys, 1883, and L. virens (Charpentier, 1825). Among teneral females of L. sponsa one can found individuals with a yellow occiput, which has not been yet acquired a bronze colour, but with a diffuse border. However, all the details of morphology of the female mentioned evidence equivocally for its being L. sponsa, that was corroborated by E.I. Malikova and R. Joedicke (Lindern, Germany). Most probably we faced some anomaly of colouration development after hatching.

The species is not numerous on the territory studied.

3. Sympecma paedisca Brauer, 1882 ssp. braueri Bianchi, 1905.

Gorb et al., 1996: Sympecma annulata Selys.

Materials: Tsasuchei: 18.VI 95 - 6m, 9.VIII 97 - 1m; Bor: 22.VIII 96 - 2m, 3f; Right Bank: 17.VIII 95 - 1m, 1f, 30.VI 96 - 1m, 1f, 18.VIII 96 - 1f, 17.VII 97 - 1m; Bridge: 22.VIII 95 - 2f; Upper Floodland: 16.VII 96 - 1f, 23.VIII 96 - 2f, 10.VIII 97 - 1f; Betevken: 4.VII 96 - 2m; Malyi Betevken: 26.VI 95 - 6m, 3f; Borzya: 21.VI 95 - 7m, 6f; Adon-Chelon: 19.VI 95 - 2f, 21.VI 95 - 1m; Mukei: 24.VI 95 - few specimens visually; Bulum: 23.VI 95 - 2m, 23.VIII 95 - 2m; Teli: 25.VI 95 - 1m, 29.VI 96 - 3m; Kuku-Khadan: 24.VI 95 - 1m, 1f; Nipsei: 15.VI 95 - 1f; Erentsav: 22.VII 96 - 1f. (63)

In a majority of specimens there is only one small gap in the mesepisternal band in the fore part of the pterothorax, in others the band is contiguous. Thus, our damseflies belong to ssp. braueri, while for the adjacent Inner Mongolia "Sympecma paedisca annulata Selys, 1887" was reported (Ma Yao et al., 1991). In the latter subspecies the band should be not only split into fragments, as in the nominotypical one, but practically reduced. Most probably there took place a subspecies misidentification.

An omnipresent damselfly, the least confined to water among all, so it is common as well on various water bodies as far from them. Its apparent abundance together with such a wide dispersion implies it is likely the most abundant damselfly in this region as well as in Siberia in general. Besides, only this species hibernates in the imaginal phase, so that the imagines are observed throughout the warm season.

Familia COENAGRIONIDAE

4. Coenagrion glaciale (Selys, 1872)

Materials: Bridge: 29.VI 95 - 2m, 5.VII 96 - 3m. (5)

The species is characterized by rather an early flight period. Probably it was finished in general before our observations had started that may explain why this species is so seemingly scarce.

5. Coenagrion armatum (Charpentier, 1840)

Gorb et al., 1996

Materials: pools on a pasture at the village Verkhnii Tsasuchei: June 1995 - visually, rather abundant; Upper Floodland: 5.VII 96 - 1m, 1f, 16.VII 96 - 1m, 1f, 18.VII 97 - 1f; Malyi Betevken: 26.VI 95 - 6m, 4f; Borzya: 21.VI 95 - 3m, 8f, 8.VII 96 - 6m, 4f; Adon-Chelon: 19.VI 95 - 1m, 20.VI 95 - 1m; Bulum: 23.VI 95 - 1m, 3f, 3.VII 95 - 1f; Teli: 25.VI 95 - 3m, 6f; Kuku-Khadan: 24.VI 95 - 2m, 2f. (56)

Rather a common damselfly on any water bodies (except for Lake Mukei), is found also far from water.

6. Coenagrion lunulatum (Charpentier, 1840) (= C. vernale (Hagen, 1839))

Gorb et al., 1996

Materials: Bridge: 18.VI 95 - 21m, 9f, 29.VI 95 - 11m, 30.VI 96 - 2m, 3.VII 96 - 1m; Upper Floodland: 2.VII 96 - 2m, 18.VII 97 - 3m, 1f; Betevken: 25.VI 95 - 21m, 6f; Malyi Betevken: 26.VI 95 - 25m, 3f; Borzya: 21.VI 95 - 19m, 7f, 8.VII 96 - 3f; Adon-Chelon: 19.VI 95 - 3m, 2f; Mukei: 15.VI 95 - 2m , 24.VI 95 - 1m, 2.VII 95 - 8m, 4f; Bulum: 23.VI 95 - 2m, 2f, 3.VII 95 - 2m, 2f; Teli: 25.VI 95 - 1m, 3f, 29.VI 96 - 1f; Kuku-Khadan: 24.VI 95 - 3m. (170)

It should be noted that the legends to the figures depicting the female pronotums of C. armatum and C. lunulatum in (Gorb et al., 1996) are confused with each other.

The most abundant damselfly species on the majority of water bodies, except for the Torei Lakes where it is inferior to C. ecornutum in abundance, and Lake Mukei where few specimens were met with, probably migrated from Lake Barun-Torei.

7. Coenagrion lanceolatum (Selys, 1872)

Materials: Bridge: 18.VI 95 - 5m, 4f (all teneral); 29.VI 95 - 12m, 8f, 30.VI 96 - 20m, 1f, 16.VII 97 - 3m, 17.VII 97 - 4m, 3f; Upper Floodland: 2.VII 96 - 7m, 4f, 5.VII 96 - 1m, 3f, 16.VII 96 - 1f, 18.VII 97 - 7m, 7f; 10.VIII 97 - 3m; Malyi Betevken: 26.VI 95 - 4m; Borzya: 8.VII 96 - 1m, 2f; Adon-Chelon: 19.VI 95 - 1m, 2f, 20.VI 95 - 1m; 21.VI 95 - 1m; Kuku-Khadan: 24.VI 95 - 2f. (107)

Males sometimes are found with lateral black strokes on the tergite II, as in a close species Coenagrion hastulatum (Charpentier, 1825), their belonging to C. lanceolatum being, however, clear from the anal appendage structure.

The species is common on many water bodies (not found on Lake Mukei), seems to be most abundant in the Onon floodland. The imagines emerge in middle/late June.

8. Coenagrion ecornutum (Selys, 1872)

Gorb et al., 1996

Materials: Bridge: 29.VI 95 - 1f, 30.VI 96 - 3m, 2f, 3.VII 96 - 1f; Upper Floodland: 2.VII 96 - 5m, 1f, 5.VII 96 - 2f, 16.VII 96 - 4m, 2f, 18.VII 97 - 8m, 5f; Borzya, 21.VI 95 - 2m, 10f (all teneral), 8.VII 96 - 5m, 3f; Adon-Chelon: 19.VI 95 - 1f, 20.VI 95 - 1f; Betevken: 25.VI 95 - 1f; Malyi Betevken: 26.VI 95 - 2m, 2f; Mukei: 24.VI 95 - 1m, 1f; Bulum (in reed thickets): 23.VI 95 - 23m, 36f (mostly teneral), 3.VII 95 - 5m; Teli: 25.VI 95 - 2m, 3f; Utycha: 25.VI 95 - 1m, 2f; Chikhalan, 12.VII 96 - 1f; Kuku-Khadan: 24.VI 95 - 3m, 1f; Khukh-Nur: 23.VII 96 - 4m, 1f. (145)

B.F. Belyshev (Áåëûøåâ, 1973) considered this species to be rare east of the upper Ob' River basin, however, E. I. Malikova (1995) noted its abundance in Transbaikalia and the Far East.

This is the most abundant damselfly of the Torei Lakes (and, most probably, of the Borzya Rivulet valley). On June 23 1995 in the reed thickets at the cordon Bulum-Khuduk a mass emergency of this species was observed, however, on the next visit to the lake on July 3 their abundance was quite moderate. Probably the damseflies had partly migrated out of the lake. Their ability of such migrations seems to be supported by a high concentration of these damseflies on the southern slope of the hill Kuku-Khadan facing Lake Zun-Torei.

9. *Cercion v-nigrum (Needham, 1930)

Materials: Bridge: 29.VI 95 - 1m, 1f; Upper Floodland: 2.VII 96 - 2m, 5.VII 96 - 4m, 2f, 15.VII 96 - 13m, 16.VII 96 - 2m, 1f, 10.VIII 97 - 1f. (27)

This species ranges in China, was known from the southern Primorye (Áåëûøåâ, 1973) and found recently in the Amur valley in the surroundings of Blagoveshchensk (Malikova, 1993, 1997) but was not so far reported for Transbaikalia. This record shifts the border of the known range of the species much to the west. Most probably, it coincides with the Amur (Heilongjiang) River basin.

Ma Yao et al., (1991) for the adjacent regions of Inner Mongolia reported Cercion sexlineatum (Selys, 1883) (now having received a priority name Cercion melanotum (Selys, 1876) (May, 1997)) but not C. v-nigrum. The latter species was described by a single male by J. Needham (1930) in his monograph "A Manual of Dragonflies of China" where a key is given including both species. Unfortunately, they are differentiated there by the humeral black stripe of the pterothorax, contiguous versus split lengthwise by a light streak. The type specimen had a contiguous stripe, however, later it was found out that this character is very variable in C. v-nigrum. Figures in B.F. Belyshev (1973) well show this variation ranging from the absence of a dividing light streak to a complete separation of the two elements of the stripe by such a streak. S. Asahina (1961, 1989) reported on specimens in which the stripe is divided in the rear part, as in C. melanotum. It is not excluded that Ma Yao et al. (1991) had in hands specimens of C. v-nigrum but, identifying them by Needham's key, came to C. sexlineatum (i.e. melanotum). Our specimens fit perfectly to C. v-nigrum by all the characters.

Our specimens show the following variation of division of the humeral stripe: in 4 males and 4 females the stripe is divided throughout its entire length, the two elements contacting each other by a tiny anastomosis only at the hind end of the stripe; in 6 males the stripe is as well divided but there are another anastomosis at its fore end so that the light streak is isolated from the ground colour of the pterothorax; in 10 males and 1 female the stripe is divided with an isolated light streak only in its hind part.

The species is rather common on stagnant eutrophic mortlakes of the Onon River right floodlands above the bridge, especially on Lake Kudon. The males tend to sit on the leaves of water plants floating on the surface. They share this feature of behaviour with Erythromma najas, that is not surprising as some researchers synonymize the genera Cercion and Erythromma.

10. Erythromma najas (Hansemann, 1832) ssp. humerale (Selys, 1887)

Materials: Bridge: 18.VI 95 - 1f (teneral), 29.VI 95 - 6m, 1f, 30.VI 96 - 6m; Upper Floodland: 2.VII 96 - 3m, 5.VII 96 - 6m, 1f, 15.VII 96 - 9m, 3f, 16.VII 96 - 1m, 17.VII 97 - 3m, 2f; 18.VII 97 - 1m; 10.VIII 97 - 1f; Bulum, 3.VIII 96 - 2m (one teneral); Chikhalan - 12.VII 96 - 1m. (47)

The taxon humerale, ranging east of Pribaikalye [i.e. Lake Baikal area] was usually considered as a subspecies of E. najas, but recently it has again acquire a species rank thanks to E.I. Malikova (1995 and personal communication), for a smaller size of the eastern taxon and differences, of a quantitative nature, in the larval morphology. On the contrary, she considered the presence and expression of the dark-yellow stripes on the fore side of the pterothorax in males as individually variable and, hence, of no taxonomical value, while these stripes were specified by B.F. Belyshev (1973) as diagnostic features of ssp. baicalensis Belyshev from East Siberia (now is synonymized to humerale) and "humeralis" (considered by him as ranging in the Far East). I think that the reasons proposed are insufficient for separation of najas and humerale at the level of species and refer rather to subspecies. R. Seidenbusch (personal communication) also found no differences of a species rank between European najas and Japanese humerale. As to the mentioned stripes, among our 36 males examined in 8 they are present and go throughout the length of the fore side of the pterothorax (in one male they are very broad), in 26 they are expressed only in the fore half of the pterothorax fore side, as it should be in humerale according to the original description, in 1 they are vexillary, in 1 they are absent, as in the typical najas.

These damseflies were common on mortlakes of the Onon right bank floodland upstream of the bridge embankment. In good weather the males almost exclusively keep to an open water surface where they rest on emerging vegetation or floating leaves and sticks. In early July 1995 all these pools were inundated by the Onon and become its fast current arms. Some damseflies were scarcely observed in the grass of non-inundated plots but no Erythromma najas were seen among them. In 1996 no changes of the Odonata community were noticed on these water bodies, left stagnant throughout the season. In 1996 E. najas was found, although rare, also on the Torei Lakes, which seem not to be too suitable for this species preferring abundant floating vegetation.

11. Enallagma cyathigerum Charpentier, 1840 ssp. risi Schmidt, 1961

Gorb et al., 1996

Materials: Tsasuchei: 28.VI 95 - 2m, 3f; Bor: 20.VII 97 - 1m; Bridge: 29.VI 95 - 2f (teneral), 30.VI 96 - 2m (teneral); Upper Floodland: 2.VII 96 - 1m, 5.VII 96 - 1f, 15.VII 96 - 1m, 18.VII 97 - 2m, 2f, 10.VIII 97 - 3m; Betevken and Malyi Betevken: 25.VI 95 - 10m, 5f, 26.VI 95 - 1f, 4.VII 96 - 3m; Borzya, 21.VI 95 - 8m, 8f; Adon-Chelon: 19.VI 95 - 1m, 2f, 20.VI 95 - 3f, 9.VII 96 - 1m; Mukei: 15.VI 95 - 2m, 5f (teneral), 2.VII 95 - 12m, 5f, 24.VIII 95 - 1m, 7.VII 96 - 4m, 5f; Mukei (a rivulet falling into it): 2.VIII 96 - 2m, 2f; Bulum: 7.VII 96 - 1f; Teli: 25.VI 95 - 6m, 3f, 29.VI 96 - 1f; Kuku-Khadan: 24.VI 95 - 4m, 2f, 24.VII 95 - 3m3f, 9.VIII 97 - 1m; Chikhalan - 12.VII 96 - 9m, 11f; Khodonyata: 15.VIII 96 - 1m, 1f; "Torei Lakes": 13.VIII 89 - 11m (E. Maksimenko); Borokholoi: 13.VIII.89 - 1m (E. Maksimenko); Duro-Nur, 23.VII 96 - 6m, 6f; Khukh-Nur: 23.VII 96 - 3m; Eltrud: 23.VII 96 - 1m; Avdar-Tolgoi: 24.VII 96 - 1f; 18 km WSW of the Erentsav railway station, a bank meadow of Lake Barun-Torei, 24.VII 96 - 1m. (174)

All the male specimens have the upper anal appendages corresponding to the taxon Enallagma risi Schmidt, 1961, described from Afghanistan and repeatedly reported for Mongolia and even South Siberia (Belyshev, 1973). The characteristic feature of the upper appendage is a small yellow lip to be situated proximally and ventrally of a robust dark terminal tooth and is directed inwards and down (Fig. 2, 4). Although there is a certain small variation in the shape of the appendages, the mentioned features are stable with no exception. This was proved by Richard Seidenbusch (Sulzbach-Rosenberg, Germany) who also stated that all the females have a more erected mesostigmal plate, that is also the peculiar feature of E. risi. Since the taxonomic situation is not yet so clear, as it is seen from the below comments, further in the text the damseflies with such characters will be called "risi-type". R. Seidenbusch (1997 and personal communication) also communicated that all specimens from Central Asia belong to the same type.

All Enallagma specimens from Europe and Asia Minor (Seidenbusch, 1997), and also from North America (A.Y. Haritonov and E.I. Malikova, personal communications), have the yellow lip to be situated distally of the terminal tooth, which is not so robust, its hind margin being directed behind. Europe and Asia Minor are inhabited with the nominotypical Enallagma cyathigerum cyathigerum, so this type of appendages will further be called "cyathigerum-type". The same structure is exhibited by specimens from the Lena River and Kamchatka, often melanistic, considered by B.F. Belyshev (1956) as Enallagma circulatum continentale Belyshev, 1956, then Enallagma cyathigerum ab. desertiformis Belyshev, 1972, and then as Enallagma cyathigerum ab. nigrolineata Belyshev, 1973 (Belyshev, 1973). Later A.Y. Haritonov and B.F. Belyshev regarded them as bona species Enallagma nigrolineata Belyshev et Haritonov, 1975 (Haritonov, 1975), although the name continentale seems to have a priority. The same appendage structure is found in the damseflies from Amurland, Primorye (Malikova, 1995) and Korea (Asahina, 1989)

I had an opportunity to look through the rich materials on Enallagma from the collection of Siberian Zoological Museum at the Institute of Systematics and Ecology of Animals, Novosibirsk. It turned out that all specimens from the northern Caspian region, Chelyabinsk Province, the southern part of the West-Siberian Lowland (surroundings of Omsk, Novosibirsk, Tomsk, Biisk) invariably belong to the risi-type. It is this type of anal appendages which is illustrated in the monograph by B.F. Belyshev (1973) for "Enallagma cyathigerum". Among specimens from the Sverdlovsk Province, the Altai Mts., Irkutsk Province and Buryatia the structure of the upper appendages varies between the two types in such an extent that in a single point the specimens of the cyathigerum-type, risi-type, and intermediates can be found together. In the northern West Siberia, NE Asia and Kamchatka all damseflies belong to the cyathigerum-type, among which melanistic individuals with black stripes on the sides of the abdomen can be met with. (It was such specimens, to my mind lacking any taxonomic value, which acquire so many names after Belyshev, namely, continentale, desertiformes, nigrolineata. It was these dragonflies which were also described by A.N. Bartenef as Agrion antiquum Bartenef, 1956 (Malikova, 1995).)

This picture make me sure that the cyathigerum- and risi-type are structural forms within the species Enallagma cyathigerum and that Enallagma risi can not be considered as bona species that was adopted in the literature sources summarizing the Siberian dragonfly fauna (Belyshev, 1973; Spuris, 1988). These types have clear-cut ranges. The cyathigerum-type inhabits Europe, Asia Minor, northern Asia, Pacific regions south to Korea, and North America. The risi-type occupies the arid (desert, steppen and forest-steppen) zones of Asia from the Caspian Sea to Transbaikalia and Manshuria. In the zones of their contacts, which are so far recognized in such more or less humid mountain regions as the Ural, Altai, and the mountains of Baikal region, which protrude into the forest-steppen and steppen zones, i.e. into the latitudes of a zonal range of the risi-type, an intensive intragression of these forms is observed. The cyathigerum-type may be considered either as a subspecies or as a group of related subspecies, since it embraces a number of taxa described, including E. c. annexum Hagen, 1861 from North America and continentale Belyshev, 1956 from NE Asia (if the latter really deserves separation). There are also a number of taxa described within the risi-type, such as Enallagma cyathigerum var. rotundatum Bartenef, 1929 (West Caucasus), Enallagma strouhali Quentin, 1962 (Harbin, China), Enallagma cyathigerum mongolicum Benedek, 1968 (Mongolia). The two latter has been reliably synonymized to risi (May, 1997). From Bartenef's figures (Bartenef, 1929) it looks possible that the taxon rotundatum is also consubspecific to risi, then the taxon would receive the priority name Enallagma cyathigerum rotundatum Bartenef, 1929. However, for a decision an detailed study of the type and other Caucasian specimens is necessary. So the risi-type so far embraces either two subspecies, rotundatum and risi, or a single subspecies rotundatum. Following R. Seidenbusch (1997), I preliminarily keep to the first version and apply the trinomen Enallagma cyathigerum risi for Daurian specimens.

In the region studied these dragonflies inhabit all the stagnant water bodies. This species predominate on Lakes Betevken and Malyi Betevken and is the only one developing in mass quantities in Lake Nizhnii Mukei. On Lake Zun-Torei these damseflies were observed on July 12-13 1996 still hatching on the leaves of Iris lactea, narrow thickets of which rimming the lake bank 1-2 m from the water.

Fig. 2. Details of morphology of Ophiogomphus spinicornis Selys, 1878, the Onon River (1-3) and Enallagma cyathigerum risi Schmidt 1961, Lake Zun-Torei (4). 1, female valvular vulvae; 2, female horns; 3, 4, male anal appendages

12. Ishnura elegans (Van der Linden, 1820)

Materials: Upper Floodland (Lake Kudon): 15.VII 96 - 1m; Bulum (in reed thickets): 23.VI 95 - 1f. (2).

This species is abundant in the western part of its range but is local and rare in East Siberia and the Far East (Malikova, 1995).

Familia AESHNIDAE

13. Aeshna mixta Latreille, 1805 (= Ae. coluberculus (Harris, 1782))

Gorb et al., 1996.

Materials: Bor: 10.VIII 97 - 3m, 1f; Right Bank: 18.VIII 96 - 1m; 3.VIII 96 - 1m; Adon-Chelon: 11.VIII 95 - 2m, 2f; Bulum: 3.VIII 96 - 1m; Kuku-Khadan: 9.VIII 97 - 1f; Utycha: 18-19.VIII 95 - 1m; Borokholoi: 13.VIII 89 - 2m, 5f (E. Maksimenko); Solovyovsk: August 1989 - 2m, 1f (E. Maksimenko). (23).

One of the most late flying dragonfly which appear in August. Rather abundant imagines were observed flying among forest edges and in open tree stands in Tsasucheiskii Bor, as well as above the upper part of the southern slope of the hill Kuku-Khadan facing Lake Zun-Torei. They don't show a noticeable trend to keep to water bodies. As different from Aeshna crenata, which usually patrol a certain individual areas with rather an even and straight flight along a more or less stable route, or Aeshna juncea, which fly in abundance without conflicts between individuals but with as well even and straight flight, this species has an uneven and twisting flight, the dragonflies as if examining tree branches, grass plots or rocks.

14. Aeshna crenata Hagen, 1856

Materials: Tsasuchei: 20.VII 96 - 2m, 1f; Right Bank: 31.VII 96 - 1m, 1f (with dark wings), 18.VIII 96 - 1m, 21.VIII 96 - 1m, 16.VII 97 - 1m, 2f; Upper Floodland and Bridge: 5.VII 96 - 1f (teneral), 15.VII 96 - 9m, 1f, 16.VII 96 - 5m, 1f, 18.VII 97 - 1m, 10.VIII 97 - 1f; Left Bank: 11.VII 96 - 5m. (34).

Two females collected on July 31 1996, had strong darkenings on the wings, that usually is a common feature of this species.

A predominating Aeshna species in the Onon floodland. Its mass emerging starts in middle July on the stagnant eutrophic Onon mortlakes, so that numerous exuvia appear on the bank sedge and snags. The males are patrolling individual areas above the water or near, very numerous on stagnant mortlakes and few on slow-current temporary arms of the Onon. The females are observed at the water as well as, most frequently, flying among sparse tree stands of riparian poplars or pines.

15. Aeshna serrata Hagen, 1856

Gorb et al., 1996.

Materials: Left Bank: 11.VII 96 - 1f; Bulum: 3.VII 95 - 1f; Teli: 27.VII 95 - 1m, 1f. (4).

These sites seem to bear the easternmost (and rather not abundant) populations of this species in Russia (B.F. Belyshev (1973) thought this species to penetrate eastwards to the Lake Baikal longitude only), that is in a good accordance with the existence here of the most eastern steppes, with which this species is undoubtedly connected.

16. Aeshna juncea (Linnaeus, 1758)

Gorb et al., 1996.

Materials: Bor: 14.VII 96 - 2m, 2f, 5.VIII 96 - 1m, 10.VIII 97 - 2m; Right Bank: 15.VII 96 - 1m (in a pine forest, V. Dubatolov), 19.VII 97 - 1f. (9).

The species is very abundant in Tsasucheiskii Bor where flies in plenties on glades and in pine tree open stands since middle July. The dragonflies exhibit a swarming flight behaviour, i.e. aggregated in certain places without fights between individuals. At the daylight they flew several metres above the ground, gradually descending to the very ground in twilight. This species was never observed at the water where only Ae. crenata, patrolling males and ovipositing females, were seen. B.F. Belyshev (1973) thought Ae. crenata is able of ejecting Ae. juncea from water bodies. The question is open if Ae. juncea in the region studied develops mostly on some other water bodies or appears at the water later in the season.

17.*Anax parthenope Selys, 1839 ssp. julius Brauer, 1866.

Materials: Mukei: 2.VII 95 - a fore and back wings of a female.

This species was known from Russian Transbaikalia only by a visual observation by B.F. Belyshev (1973) at Lake Gusinoe, Republic Buryatia. According to venation, the wings collected belong undoubtedly to the genus Anax. It is A. parthenope which is known from the adjacent regions of Mongolian People's Republic (Bbelyshev, Doshidorzhi, 1981) and Inner Mongolia (Ma Yao et. al., 1991). There is no doubt we also deal with this very species. The pterostigm length is 5.5 mm in the fore wing and 6 mm in the hind wing, i.e. not less than 5 mm that, according to (Belyshev, 1973), corresponds to the subspecies A. p. julius Brauer inhabiting the eastern range of the species.

When visiting Lake Nizhnii Mukei on July 2 1995 we also observed dragonflies of the Aeshnidae family visually. We frightened several very teneral individuals resting about 10 m of the water. Besides, few dragonflies permanently flew above the slope of a hill facing the southern bank of the lake, keeping to more or less expressed individual areas. These dragonflies correspond to A. parthenope in their size, a green coloration of the thorax sides and a blue colours on the thorax dorsal side at the wing bases were seen. Unfortunately, we failed to catch any specimen.

On July 20 1996 a just hatched male specimen of this species was collected by V.A. Brinikh in the Alkhanai National Park on lakes near Eber-Alkhanai (150 km NW of Lake Nizhnii Mukei). This is a first full specimen collected from Transbaikalia, which evidence for this species not only flies but as well develops on this territory.

Familia GOMPHIDAE

18.*Ophiogomphus spinicornis Selys, 1878

Materials: Tsasuchei: 28.VI 95 - 1m1f, 16.VIII 96 - 1f; Bor: 14.VII 96 - 6m, 4f, 5.VIII 96 - 1m, 2f, 10.VIII 97 - 1f; Right Bank: 30.VI 95 - 1f, 5.VII 95 - 5m, 4f, 17.VIII 95 - 2m, 2.VII 96 - 3m, 5f, 15.VII 96 - 3m, 31.VII 96 - 2f, 18.VIII 96 - 1m, 23.VIII 96 - 1m, 16.VII 97 - 2m; Upper Floodland: 18.VII 97 - 1m; Left Bank (a floodland): 1.VII 95 - 1m, 18.VIII 96 - 1m, 1f; Left Bank: 11.VII 96 - 5m, 7f (Kosterin, Dubatolov). (62)

The species was known from China (from Hopei in the south to Inner Mongolia in the north) and Mongolia (Asahina, 1979). For Russia it was mentioned only in a collective monograph by B.F. Belyshev et al. (1989), where is found in Table 1 as presenting in the East Asiatic (Amurian) Zoogeographic Subregion (including the Upper Amurland and Primorye), without any textual references. Later it was not mentioned in a special assessment of the fauna of thus region (Malikova, 1995). Noteworthy, it was reported for an adjacent territory of Inner Mongolia only for the basin of the Noini (Nunjian) River, a tributary of the Sungari River, i.e. at the eastern foot of the Great Hingan Mts. [Da Hinggan Ling], for the sites Yalaid Qi and Horquin Youyi Zhongqi, i.e. about 700 km SE of our territory (Ma Yao et al., 1991).

The species differs well from a similarly ornamented Ophiogomphus serpentinus (Charpentier, 1825) first of all with the male anal appendages (the upper ones being robust, curved inwards, 2/3 longer than the lower ones, see Fig 2, 3), by a more widely incised valvular vulvae of females (Fig. 2, 1), and by a somewhat larger size (Asahina, 1979). By these characters it approaches to some extent to the Central Asian/Indian Ophiogomphus reductus Calvert, 1898). I have found out that the dragonflies "combining characters of Ophiogomphus serpentinus and O. reductus", abundantly inhabiting the Tes-Khem River in South Tuva, which were mentioned in (Zaika, Kosterin, 1992), belong in fact to this very species. B.F. Belyshev (1973) considered the taxa O. cecilia (Fourcroy, 1785) (now the name serpentinus is accepted for it), obscurus Bartenef, 1930, reductus, and, presumably, spinicornis as subspecies of the same species O. cecilia while other authors show convincingly that they are true species (Belyshev, 1930; Asahina, 1979; Haritonov, Borisov, 1990). B.F. Belyshev (1973) noted that at Lake Gusinoe (not far from Lake Baikal) he met with "cecilia, obscurus, and individuals transitory between them". I failed to found these materials in the collection of Siberian Zoological Museum at the Institute of Systematics and Ecology of Animals, Novosibirsk. But I have found there three doubtless specimens of O. spinicornis from the southern coast of Baikal: a male and female with the label "[The Selenga River delta, Murdino]", 1.VII 85 and 11.VII 1985, respectively (B.P. Zakharov leg.), and a male from the village Tankhoi, 28.VII-3.VIII 1980 (A.V. Barkalov leg.). Thus, this Mongolian-Chinese species enters the territory of Russia in Tuva, Buryat Republic at Baikal, and Transbaikalia following the steppen landscapes of Mongolian type (although the southern coast of Lake Baikal is covered with taiga). Noteworthy, when we visited the lowest Argun' River valley at the village Uryupino (the Easternmost Chita Province) in July/August 1997, which has quite woody landscapes, we found there only O. obscurus.

Besides, I was an opportunity to examine two more specimens from the Siberian territory east of Baikal, from the Baikal'sko-Stanovoe Upland: there is a female from the Verkhnyaya Angara River (the precise location, date and collector unknown) and a very similar female from the same region, collected by R. Dudko on August 4, 1995 in an alpine belt (!), on the altitude of 1600-1770 m, of the western part of the Verkhneangarskii mountain range, 30 km NW of the village Kumora. These two females can be reliably identified as O. serpentinus, however, in this zone O. obscurus would rather be expected. They has a light spot on the vertex, the face and thorax colouration and a relative distance between the horns identical to serpentinus (Belyshev, 1930; Haritonov, Borisov, 1990), the only deviation towards obscurus is a somewhat more developed black colouration on the abdomen (it is such specimens which could mislead B.F. Belyshev). These females differ from spinicornis by a smaller size, less widely incised valvular vulvae, slightly more developed black colouration on the abdomen and face. Special investigation of Ophiogomphus in North Transbaikalia, as well all over the intricate zones of presumed contacts of the four Palaearctic taxa are necessary to reveal their true ranges and to prove eventually their species separation, which seems now doubtless.

These dragonflies are quite numerous along the Onon River and penetrate rather far into open parts of Tsasucheiskii Bor, where they usually rest on sunny pine branches 1,5-2 m high, less frequently on the ground.

In 1995 teneral individuals appeared in late June. Numerous exuvia of this species were collected on July 16 1997 near the water on a shingle left bank of the Onon River under the hill Malyi Batur, where the river has a very fast flow and undermines a rocky cliff, several exuvia were found also on the right bank 12 km upstream of Nizhnii Tsasuchei, under a sandy-loam bluff. In both places the river has a united powerful flow.

19.*Anisogomphus maackii (Selys, 1872) (= Gomphus m-flavum (Selys, 1872)).

Materials: Tsasuchei, 14.VII 96 - 1 specimen (visually and photographed); Right Bank: 5.VII 95 - 1f (O. Berezina), 30.VI 96 - 1f, 16.VII 96 - 1f; The Onon River right bank 1 km upstream of the bridge: 18.VII 97 - 1f, 18-19.VII 97 - several males visually; Left Bank - 11.VII 96 - 1f. (5).

In a specimen collected in 1995 the postclypeus has no yellow spots on its sides so being entirely black. Other specimens fully fit the description by J. Needham (Needham, 1930) (given as Anisogomphus m-flavum) and pictures by S. Asahina (1979). It worth mentioning that it was only smaller yellow spots on the sides of postclypeus and widened black stripes on the frons which made A. N. Bartenev to describe a species Temnogomphus amurensis (Bartenef, 1930) from the Blagoveshchensk District as separate from "T. m-flavum" (Belyshev, 1930), which was later synonimized to A. maacki (Asahina, 1979).

The species was known from North and Central China, Korea, Japan, the southern Amur Province (Amurland) (Asahina, 1979; Malikova, 1993; 1995; 1997a). This finding extends the known range of the species westwards. The closest known locality is 700 km south-east, Yalaid Qi, the Noini (Nunjian) River basin, the eastern foot of the Great Hingan Mts. [Da Hinggan Ling], Inner Mongolia, reported together with O. spinicornis (Ma Yao et al., 1991). It should be noted that the type specimen of the species was labeled "Irkutsk" but all odonatologists thought that this label indicated at only an administrative centre of a vast territory while the real locality should have been much easterly.

Besides, on July 30 1997 a female of this species was caught by V.V. Dubatolov in the extreme east of the Chita Province, in an open birch-larch forest with participation of the Mongolian oak on a slope of left coastal mountains in the Argun' River valley 11 km S of the village Uryupino.

The absence of males in our collection is intriguing. Most probably this is conditioned by a peculiar behaviour of the species which we could observe on the Onon River about 12 km upstream of Nizhnii Tsasuchei. In the evening of July 18 and about 11-12 hr on July 19 we observed several males (up to 4 seen simultaneously) flying low above swiftly current waters of Onon, they try to chase each other upon approaching. One of them several time sat to rest on a light-coloured rug put just near the water, it was very cautious. On sunrise of June 18 we saw a female which flew just above the water, collected something from the surface and then sat on a bush on the bank. Thus, males of this species seem to spend most active time above the water resting just near it. Females spend more time above the ground but are also seen above the water. Maybe these dragonflies feed by insects floating on the surface and their so long, robust and spiny hind femora are specialized for collecting the prey from the water. However, on July 16 1996 in a riparian part of Tsasucheiskii Bor I observed a female captured a butterfly Coenonympha amaryllis (Stoll, 1782).

On July 16 1997 two exuvia of this species were collected on a shingle left bank of the Onon under the hill Malyi Batur among numerous exuvia of O. spinicornis.

20.Stylurus flavipes (Charpentier, 1825)

Gorb et al., 1996: Gomphus flavipes sibirica Bartenef

Materials: Tsasuchei: 28.VI 95 - 2m; Bor: 14.VII 96 - 1m, 1f; Right Bank: 5.VII 95 - 2m, 1f, 30.VI 96 - 2m, 2.VII 96 - 1f, 15.VII 96 - 1f, 19.VII 97 - 1m, 1f; Left Bank: 5.VII 95 - 1m; 17.VIII 95 - 1m, 1f; 22.VIII 95 - 1f; 11.VII 96 - 1m. (18).

The abdomen length is 34-35 mm in males, 36 mm in females. There seem to be no reason do isolate ssp. sibirica Bartenef, 1909, differing, according to B.F. Belyshev (1973) only by the abdomen being less than 36 mm. In the original description the black pattern of the pterothorax was also mentioned as a diagnostic feature. However, this pattern is variable and B.F. Belyshev (1973) quite reasonably rejected its relevance. Among our material the humeral and antehumeral black stripes are fused each other both at the fore and hind end in 10 specimens, only at the fore end in 12 specimens, not fused in 2 specimens. I think the subspecies sibirica should be synunymized to the nominotypical one.

The species is common along the Onon River but is much less numerous than O. spinicornis.

Imagines appear, as in O. spinicornis, in late June. On July 16 1997 an exuvium of S. flavipes was collected near the water on the shingle left bank of the Onon together with those of the above two species.

Familia CORDULIIDAE

21.Epitheca bimaculata (Charpentier, 1825)

Materials: Bor: 14.VII 96 - 1f; Right Bank: 5.VII 95 - 1m, 2.VII 96 - 1m1f, 3.VII 96 - 1m, 1f, 19.VII 97 - 1f; Bridge: 18.VI 95 - 1f, 29.VI 95 - 1m, 1f, 30.VI 95 - 2m, 1.VII 96 -1m; Upper Floodland: 5.VII 96 -3m, 2f; Left Bank (Malyi Batur): 5.VII 95 - 1m; Adon-Chelon: 20.VI 95 - 1f, 21.VI 95 - 1f. (21).

In all our specimens the length of the hind wing is within 37-39 mm, that of the abdomen (without the anal appendages) within 34-39 mm. For both parameters the value of 40 mm was considered by B.F. Belyshev (Belyshev, 1973) for subspecies identification: in the nominotypical one their values are not less, in two Siberian ones less than 40 mm. In E. b. altaica Belyshev, 1951 the basal spots on the hind wings should reach the triangle or even occupy it, in an East-Siberian E. b. sibirica Selys, 1887 they do not reach the triangles. Belyshev believed that the latter ranges east of Baikal but not north of its latitude, where the typical subspecies is distributed. Among our specimens in 1 male and 1 female the spots occupy the entire triangle, in 1 female the spot reaches the middle of the triangle, in 1 male and 1 female the spot reaches the triangle and rests against its base; in 2 males and 1 female the basal spots just touch the triangle, in 5 males and 2 females the spot somewhat does not reach the triangle. This variation in the development of basal spots and of the length of the hind wing and abdomen, so closely reaching the "critical value", evidence for the reasons for subspecies isolation within this species to be rather weak, so I suggest to synonymize all the three subspecies.

In the studied region this is a quite numerous species (as different, for instance, from West Siberia), which is common also far from the water, in open stands of Tsasucheiskii Bor and on the massif Adon-Chelon, where these dragonflies kept to edges of dense birch and asp groves, up to several individuals being seen simultaneously. The species was not met with at all in the depression of the Torei Lakes.

22. Somatochlora graeseri Selys, 1887

Materials: Tsasuchei: July 1996 - 1m (L. Klochikhina); Bor: 29.VI 95 - 1f; Right Bank: 1.VII 95 - 1m, 2.VII 96 - 1f; Bridge: 5.VII 95 - 1m. (5).

Although only five specimens were collected, in early July 1995 this species was common, together with the previous one, but less frequently, on vast glades and open tree stand in a pine forest. The dragonflies were on a trophical flight, often very high. Besides, the males were quite common on mortlakes of the Onon right floodland, they flew low on the water along the banks patrolling large individual areas. In 1996 the species was much less frequent.

23. Somatochlora metallica (Van Der Linden, 1825) ssp. exuberata Bartenef, 1911

Materials: Bor: 22.VIII 96 - 1f; Left Bank: 11.VII 96 - 1f. (2).

The taxon exuberata had been described as a species but for a long time was considered as a subspecies of S. metallica (Belyshev, 1973; Spuris, 1988). E.I. Malikova (Malikova, 1995) again ascribe it a species status, with the following features differentiating it from S. metallica (personal communication): there is two isolated yellow spots on the forehead except for a transversal yellow stripe (the main character), a dull bronze-green colouration instead of bright blue-green, less size. However, the species rank of these differences needs in corroboration, preferably by the study of the zone of contact of the taxa presumed to be in Central Siberia.

Familia LIBELLULIDAE

24. Pantala flavescens (Fabricius, 1798)

Materials: Bor: 15.VII 96 - 1m (visually), 10.VIII 97- 1f; Upper Floodland (a dried up mortlake at the Onon River): 16.VII 97 - 2m, 1f (visually); Left Bank: 11.VII 96 - 3m; Chikhalan: 12.VII 96 - 1f. (5).

All the specimens collected have a well developed tiny dark spot at the apex of the hind wing.

A circumtropical species reaching the latitude of the former Central Asian Republics of the USSR but in East Asia recorded north to South Kamchatka (Áåëûøåâ, 1973). In Transbaikalia it was reported from the village Pokrovka at the junction of the Shilka and Argun' Rivers (Selys Longchamps, 1887). Belyshev considered this report as erroneous thinking that this species can not penetrate so northerly at this longitude. On July 11, 1996 I observed and captured three males of this species 10 km west of Nizhnii Tsasuchei, slow and low flying above temporary pools formed on the left bank of the Onon River as a result of its high flood; on July 15 a male was observed above a pool at the highway 5 km west of Nizhnii Tsasuchei; on July 12 a female was caught above a low hill at the foot of the hill Chikhalan on the Lake Zun-Torei northern bank. On July 19, 1997 a male and an ovipositing pair were observed above a dried up, to a wet ground, temporary arm of the Onon right bank 13 km W of Nizhnii Tsasuchei. On August, 11 1997 a female was caught on a wide clearing along the highway in Tsasucheiskii Bor. Besides, on July 24, 1997 an individual was observed above the Gazimur River upstream of the settlement Gazimurskii Zavod, i.e in a very different eastern woody part of the Chita Province. Thus, this species is indeed present in the Province.

In most cases these dragonflies were found above temporary pools in which larval development seems to be impossible. It is noteworthy that B.F. Belyshev (1973) also wrote that "the species was observed by us repeatedly in the Monkhukhai River valley in the southern part of Primorye but always far from water bodies where it could breed". Since these dragonfly are famous for their powerful flight, it is possible we faced migrants from more southern regions. However, Dumont and Heidari (1996) noted: "... a temporary rainpool, a type of biotope often favoured by this species for oviposition and (rapid) larval development". It should be noted that in our region temporary pools are characterized by an exceptional abundance of ephemeric crustaceans: Notostraca, Anostraca, and Conchostraca, that is they have a substantial forage reserve for predators. So, the question of possibility of development of these dragonflies in the southern Transbaikalia, at least in summer, is left open.

25. Leucorrhinia (rubicunda (Linnaeus, 1758)) intermedia Bartenef, 1910

Gorb et al., 1996.

Materials: Bridge: 30.VI 95 - 2m, 1f, 30.VI 96 - 1f, 1.VII 96 - 1m; Upper Floodland: 5.VII 96 -3m, 4f, 15.VII 96 - 2m, 18.VII 97 - 1f; Malyi Betevken: 26.VI 95 - 1m, 2f; Adon-Chelon: 19.VI 95 - 1f, 21.VI 95 - 1m; Kuku-Khadan: 14.VI 95 - 3m, 4f, 24.VI 95 - 1m. (28).

The differences by which B.F. Belyshev in his key (Áåëûøåâ, 1973) suggested to distinguish close vicariant species L. rubicunda (the western one going east to the Altai Mts.) and L. intermedia (the eastern, going west to the Yenisei River basin and, again, Altai), seem to be vague: the presence of lateral ribs on the IV-VIII abdominal segments in the former and on the (V) - VI -VII - (VIII) segments in the latter. Indeed, in our specimens these ribs are either not present or hardly noticeable on the VI-VII segments. Besides, the cited author wrote "anyway, it doesn't matter at all... either they are well differentiated subspecies or weakly formed close species with prevailing of only quantitative differences in their peculiarities". However, below he mentioned some qualitative morphological differences which, as it follows from the below text, most probably concern the genitalia. E.I. Malikova (personal communication) confirmed that the ribs are an unreliable characters while the differences in the male secondary genitalia are stable and reliable. Most probably, solution of the problem of independence of intermedia and rubicunda needs in special serial studied in the zone of their contact, as in other similar cases. As note being an expert in the problem, I attribute the specimens collected to the taxon intermedia solely on the base of their provenance and provisorily retain the species rank for the taxon, expressing the mentioned doubts by putting an intercalate name of the species group.

A numerous spring species flying, however, up to middle July (in 1996 this species had already disappeared to this time, as different from L. quadrimaculata).

26. Libellula quadrimaculata Linnaeus, 1758 ssp. orientalis Belyshev, 1956.

Gorb et al., 1996.

Materials: Bor: 30.VI 95 - 1f ; Right Bank: 30.VI 95 - 1m, 16.VII 97 - 1m; Upper Floodland: 15.VII 96 - 1m, 18.VII 97 - 1m; Malyi Betevken: 26.VI 95 - 2m; Adon-Chelon: 19.VI 95 -1f, 21.VI 95 - 1f; Kuku-Khadan: 14.VI 95 - 1m, 2f, 24.VI 95 - 1m; Teli: 25.VI 95 - 1f (aberrant, the nodal spots being much enlarged reaching the vein M and extending for 5 mm along the wings). (14).

By the characters enumerated by B.F. Belyshev (1973) we attribute our specimens to the eastern subspecies L. q. orientalis Belyshev, 1956: a yellow colour prevailing substantially in the colouration of both labrum and the lobes of the labium; the costal and subcostal veins are as a rule light coloured. Only in 3 our males and 3 females the costal vein becomes dark after the node. However, such a characteristic of the subspecies as the presence of additional small yellow spots, beside two large ones, on the rear side of the head is seen only in two males of 14 specimens: they have one tiny additional spot. B.F. Belyshev (1973) reported the eastern subspecies only for Primorye and wrote that in specimens from Khabarovsk "all the characters of the subspecies are already very retired". But E.I. Malikova (1995) reported it also for Amurland.

All our specimens lack basal spots on the fore wings. In five specimens collected first in 1995, that is on June 14 on Kuku-Khadan (1 male and 2 females) and on June 19 and 21 on Adon-Chelon (2 females), and also in a aberrant female from Tsasucheiskii Bor collected on June 15, the yellow colouration expands from the wing base along the costal margin of wings up to their apices, in other specimens it is present only at wing bases not trespassing the triangles.

This species, numerous up to middle July, prefers small water bodies and can be found on very small ones, say, those on a pasture at the village Verkhnii Tsasuchei. On the mortlakes at the bridge they usually occupied branches of dead riparian willow bushes, on Lake Malyi Betevken they keep to a reed thicket, on Lake Zun-Torei to bush thickets at the foots of the coastal hills, on the Adon-Chelon massif (where they were quite abundant) to edges of aspen and birch groves at rocks, occupying dry branches.

27. Sympetrum danae (Sulzer, 1776) (= S. scoticum Donovan, 1811)

Gorb et al., 1996: Sympetrum danae matrix Bartenef, 1915.

Materials: Bor: 22.VIII 96 - 1m, 10.VIII 97 - 2m, 1f; Right Bank: 17.VIII 95 - 1m, 18.VIII 96 - 1m, 4f; Bridge: 15.VII 96 - 1f; Upper Floodland: 16.VII 96 - 1f, 10.VIII 97 - 4f; Bulum: 23.VIII 95 - 1f; Teli: 19.VIII 95 - 1f; Uglovoe: 24.VIII 95 - 2m, 2f; Mukei: 24.VIII 95 - 1f; Khodonyata: 18.VII 96 - 1f, 15.VIII 96 - 1f; Solovyovsk: 18.VIII 95 - 2m; 18 km WSW of the station Erentsav, a bank meadow of Lake Barun-Torei, 24.VII 96 - 1m, 1f; Shudu-Gol: 22.VII 96 - 1m, 1f. (31).

Three our females have a certain smoky darkening at the node and pterostigm which, according to B.F. Belyshev (1973; Belyshev, Doshidorzhi, 1958), characterize specimens from Mongolia and adjacent regions. This author ascribe such dragonflies, first described as an aberration, a status of subspecies S. scoticum matrix Bartenef, 1915. 11 other our females have no darkenings. So, either our region lies in a transition zone between subspecies or the subspecies matrix was isolated basing on the unreliable character expressed not in the majority of specimens, that could not be reasonable. Most probably, the darkenings are environmental modification and result from larval development at rather high temperatures.

The species appears in middle June and is frequent, especially on vast temporarily inundated sedge tussock areas of the floodland where it develops.

28. Sympetrum depressiusculum Selys, 1841.

Gorb et al., 1996.

Materials: Bor: 9.VIII 97 - 1m; Kuku-Khadan: 9.VIII 97 - visually. (1).

Our specimen has yellow patches on the fore femora (as different from S. frequens sensu Belyshev (1973) which has the legs entirely black).

The species was reported by (Gorb et al., 1996] for the Borokholoi Rivulet, we collected one specimen in Tsasucheiskii Bor, besides, one specimen was observed on a rocky southern slope of the hill Kuku-Khadan. Most probably this is a rare species with a late flight period. It is common in the eastern part of Mongolia (Belyshev, Haritonov, 1981; there mentioned as Sympetrum frequens Selys, 1833).

29. Sympetrum flaveolum (Linnaeus, 1758)

Gorb et al., 1996.

Materials: Bor: 10.VIII 97 - 1m, 4f; Right Bank: 17.VIII 95 - 1m, 19.VII 97 - 5m, 2f; Upper Floodland: 15.VII 96 - 2m, 4f, 16.VII 96 -1m, 1f, 18.VII 97 - 1m, 1f; 10.VIII 97 - 6m, 1f; Adon-Chelon: 8.VII 96 - 2m, 1f, 9.VII 96 - 5m, 4f; Bulum: 3.VII 95 - 3f; Uglovoe: 24.VIII 95 - 1m; Khodonyata: 18.VII 96 - 2f; "Torei Lakes": 13.VIII 89 - 1m, 1f (E. Maksimenko); Shudu-Gol: 22.VII 96 - 1f. (51).

The species is famous for its variation in wing colouration. Among the collected specimens 41 have the colouration of forma typica (the females are of typica heterochrom), in 2 males the basal spots on the hind wings almost reach the nodes (that does not fit to aberrations characterized by B.F. Belyshev (1973)), 2 females are ab. flaveolata Selys (with the yellow colouration extending almost halfway between the node and pterostigm), 1 female is ab. hyalinata Rodz. (the yellow spots are absent).

This species, the commonest in Europe and West Siberia, is less numerous in Dauria. In the Onon valley it is most frequent on temporarily inundated sedge tussock floodland and on temporary arms, the biotopes this species prefers for breeding.

30. Sympetrum pedemontanum (Allioni, 1766) ssp. intermedium Belyshev, 1995.

Gorb et al., 1996.

Materials: Tsasuchei: 16.VIII 95 - 2f, 16.VIII 96 - 2f; Right Bank: 17.VIII 95 - 1m, 1f, 31.VII 96 - 1f; 18.VIII 96 - 1f, 21.VIII 96 - 1f; 23.VIII 96 -2f, 16.VII 97 - 1m, 17.VII 97 - 1f, 18.VII 97 - 1f, 10.VIII 97 - 4m; Bridge: 22.VIII 95 - 1f; Left Bank - 18.VIII 96 - 1m; Mukei: 24.VIII 95 - 1f; Uglovoe: 24.VIII 95 - 2m; Kuku-Khadan: 21.VII 95 - 1f, 9.VIII 97 - 1f; Khodonyata: 15.VIII 96 - 1f. (26).

As it was expected from the literature (Belyshev, 1973), our specimens belong to ssp. S. p. intermedium ranging from Altai to Middle Amurland: the wing band is 4-5 mm wide along the costal margin, it starts closer to the pterostigm than to the node and ends at the middle of the pterostigm.

The species is met with by few specimens in Tsasucheiskii Bor, at the Torei Lakes and in the Onon floodland. It was found to be abundant on terraces of the right board of the Onon River valley at temporary arms of the Onon, stagnant and partly dried up almost throughout the year but nevertheless oligotrophic due to infiltration of cold ground water; they become current only during the summer flood. This species prefers such water bodies all over Siberia (Belyshev, 1973).

31. Sympetrum vulgatum (Linnaeus, 1758) imitans Selys, 1886

Gorb et al., 1996.

Materials: "Daurian Reserve": 1989 - 2m, 3f (collector unknown); Tsasuchei: 16.VIII 95 - 1f, 9.VIII 97 - 2f; Bor: 20.VII 96 - 1m, 2f, 29.VII 96 - 1m, 1f (V.A. Brinikh), 1.VIII 96 - 3m, 3f, 22.VIII 96 - 2f, 20.VII 97 - 2m, 2f, 10.VIII 97 - 9m, 4f; Right Bank: 17.VIII 95 - 2m, 4f, 15.VII 96 - 1f, 16.VII 97 - 1m, 17.VII 97 - 2f; Bridge: 22.VIII 95 - 2f; Upper Floodland: 15.VII 96 - 1f, 16.VII 96 - 1f, 10.VIII 97 - 2f; Left Bank: 11.VII 96 - 1f; Adon-Chelon: 11.VIII 95 - 3m, 1f; Bulum - 3.VIII 96 - 1m; Teli: 19.VIII 95 - 3m, 3f; Kuku-Khadan: 21.VII 95 - 1m, 3f; Chikhalan - 12.VII - 1m, 2f; Khodonyata - 15.VIII 96 - 1f; "the southern end of Lake Zun-Torei": 9.VIII 95 - 1m, 4f; Solovyovsk: 17.VIII 95 - 1m, 1f; "The road along the Torei Lakes": 12.VIII 89 - 4m, 4f; "In a truck radiator, from Solovyovsk to Batukha" [i.e. shepherd Batukha's stand at Kuku-Khadan]: 14.VIII 89 - 10m, 11f. Avdar-Tolgoi: 24.VII 96 - 1f; 18 km ESE of the station Erentsav, a bank meadow of Barun-Torei, 24.VII 96 - 1m; Shudu-Gol: 22.VII 96 - 2m, 1f; Chulun-Khorot, 25.VII 96 - 1m. (111).

This taxon ranges in Transbaikalia, the Amur River basin, Primorye, China (Ìàëèêîâà, 1995). Sympetrum imitans, as a species, was described by a single female from Peking and then redescribed by both sexes from the village Pokrovka at the junction of Shilka and Argun' Rivers (Selys Longchamps, 1887). A.N. Bartenef (1915) and later B.F. Belyshev (1973) and Z. Spuris (1988) considered it as a subspecies of S. vulgatum, but E.I. Malikova (1995) re-ascribed it a species rank basing on the absence of dorsal spines in the larvae. She had only few larvae in her hands. However, later it turned out that the number and expression of dorsal spines varies greatly and continually in this taxon, up to disappearance. This was shown in 1997 by R. Seidenbusch (personal communication) who examined a series of exuvia collected by O. Berezina in 1997 on a derelict mine on the Gazimurskii mountain range between the villages Kurleya and Budyumkan, the Gazimurskozavodskoi District, the eastepn Chita Province, and in 1998 by E.I. Malikova (personal communication) on further materials from the Amur Province. Thus, the status of imitans should be reconsidered when the detalied data from the regions of its contact with S. vulgatum vulgatum were available.

In our imagines the diagnostic features of the taxon are very well expressed, which are a large size (the length of the abdomen is 27-30 mm, of the hind wing 31-34 mm) and, in females, a presence of yellow colouration at the base and along the costal margin of the wings, which is poorly expressed only in 6 of 34 studied females.

The most numerous and omnipresent dragonfly in Dauria.

Distribution of dragonflies on the water bodies.

As to distribution of dragonflies over the water bodies in the region studied the following notes can be made. The dragonfly community most rich in species was found on the Onon River valley (29 species) where all the species were present, except for A. parthenope and S. depressiusculum. Note only three Gomphid species are strict rheophils. Among them Ophiogomphus spinicornis scatters rather far from the river to be abundant in the Tsasucheiskii Bor pine forest for 1-2 km from the bank, Stylurus flavipes is seldom seen in the forest, while Anisogomphus maackii doesn't migrate off the river, males flying above the surface or sitting just near the water and only females being found within several hundred metres off the bank. Abundance decreases drastically from the first to the third species, it is not excluded that the more migrating is a species the greater forage reserve enjoy its imagines. A complete absence of representatives of the genus Calopteryx on the Onon River worth mentioning.

Other species are connected with stagnant water bodies of the floodland, first of all of the right bank floodland upstream of the bridge embankment of the highway Nizhnii Tsasuchei - Aginskoe. These are eutrophic shallow and well warmed up mortlakes which can become inundated by current waters of the Onon for a short time upon the highest floods. Most rich in dragonflies is Lake Kudon situated at the valley right board 12 km upstream of Nizhnii Tsasuchei.

Imagines of one of the species, Sympetrum pedemontanum, were found to be abundant at oligotrophic temporary arms of the Onon being stagnant and partly dried up for the most part of the year. Other dragonflies are scarce at such oligotrophic arms.

On the pasture in the Onon floodland at Verkhnii Tsasuchei there are small pools, some of them seem to be constant as there is Ceratophyllum growing in them. There were S. paedisca, C. lunulatum observed on these pools in great amount in June, less numerous were C. armatum, among Anisoptera there are present (and, most probably, breed) L. intermedia, L. quadrimaculata, species of Sympetrum.

The Borzya River was examined only twice but even during this insufficient study rather a substantial diversity of damseflies (6 species) were observed: Sympecm paedisca, Coenagrion armatum, C. lunulatum, C. lanceolatum, C. ecornutum, Enallagma cyathigerum.

The same situation is with Lake Betevken. 8 species were found (Sympecma paedisca, Coenagrion armatum, C. ecornutum, C. lanceolatum, C. lunulatum, Enallagma cyathigerum, Leucorrhinia intermedia, Libellula quadrimaculata), there are no interesting findings but the lack of observations from middle June to August does not allow to judge of the fauna.

The fauna of the Torei Lakes is not so rich, 20 species being revealed so far: Lestes dryas, L. sponsa, Sympecma paedisca, Coenagrion armatum, C. lunulatum, C. lanceolatum, C. ecornutum, Erythromma najas (quite surprising for a mineralized (about 1 g/l) lake), Enallagma cyathigerum, Ishnura elegans, Aeshna serrata, Ae. mixta, Pantala flavescens, Leucorrhinia intermedia, Libellula quadrimaculata, Sympetrum danae, S. vulgatum, S. depressiusculum, S. flaveolum, S. pedemontanum. But it seems even surprisingly diverse if to take into account a certain mineralization of the lakes and their cyclicity to complete disappearing. Most probably, dragonflies survive the minima on the Uldza (Uldz-Gol) River falling into the lakes. Anyway, dragonfly population on these lakes can not be stable.

The presence of Odonata on Lake Nizhnii Mukei is very interesting. It has a salinity of 17 g/l but is fed also by freshwater ground sources (V. Obyazov, personal communication). Five dragonfly species were recorded on this lake: Sympecma paedisca, Coenagrion ecornutum, C. lunulatum, Enallagma cyathigerum, Anax parthenope. Among them E. cyathigerum surely develops on the lake in mass quantities, that is proved by the presence of larvae in the water and teneral specimens on the banks. Three teneral specimens of Aeshnidae (most probably Anax parthenope) frightened by us from the banks hatched certainly on the same day, i.e. on the same lake.

Dragonflies reach the elevation of Adon-Chelon when they spread from distant water bodies, small steppen lakes and the Borzya River. It can be noted they are abundant and rather diverse there (12 species, Sympecm paedisca, Coenagrion armatum, C. lunulatum, C. lanceolatum, C. ecornutum, Enallagma cyathigerum, Aeshna mixta, Epitheca bimaculata, Leucorrhinia intermedia,Libellula quadrimaculata, Sympetrum flaveolum, S. vulgatum, that is more than was found for the same time in the same season on Lakes Betevken and Malyi Betevken), although no very interesting species were found. A somewhat prevailing of females in the materials collected there can be noted, while in collections made at the water males strongly predominate. This is likely due to the fact that females of Odonata in general are less connected with water bodies as feeding during the imaginal phase, often taking place far from the water, is more important to them for egg production while males soon after hatching concentrate at the water to wait for females.

Comparison of the fauna of the Daurian Rezerve and the Onon River valley with those of adjacent territories.

It is interesting to compare the fauna revealed for the Daurian Reserve and the Onon River valley at the village Nizhnii Tsasuchei with the species composition of dragonflies known for the adjacent regions (alhtough much larger ones), that is made in Table 1.

It contains the fauna of "the mountains of Transbaikalia" following I.N. Haritonova (1990), fauna of Mongolia (Belyshev, Doshidorzhi, 1958; Belyshev, 1961; Krylova, 1974; Belyshev, Haritonov, 1981, Peters, 1981, Malikova, 1997b) and the fauna of the lowland territory of Inner Mongolia (a province of China) adjacent to the Russian territory and sharing common nature conditions with the Daurian Reserve (this territory is occupied with a Chinese nature reserve Dalainor), which is bordered in south-east with the Da-Hinggan-Ling Mts. and embraces the basins of Lake Dalainor (Hulunchi) and River Argun' (Hailar) (Ma Yao et al., 1991).

In this table the species Sympetrum (vulgatum) is accepted in a broad sense, i.e. including the taxon imitans, as its western limit crosses the Mongolian territory but is not studied yet. Somatochlora (metallica) is also accepted in a broad sense as including exuberata (occupying all these territories).

In the list of fauna of "the mountains of Transbaikalia" (Haritonova, 1990) I replace Calopteryx virgo (Linnaeus, 1758) with Calopteryx japonica Selys, 1869, as E. I. Malikova (1995) showed convincingly that the taxon japonica (it is this taxon which inhabits Transbaikalia) is not a subspecies of C. virgo but a clear-cut species.

From the fauna of Mongolia I exclude Enallagma strouhali Quentin, 1962 and Enallagma risi Schmidt (doubtless synonyms, the taxon being considered here as E. cyathigerum risi), Sympetrum frequens Selys, 1883 (the continental specimens belong in fact to S. depressiusculum) and Ae. lucia Needham, 1930 Asahina (1988) believes that the latter is a synonym of Ae. mixta: the species was described by a single specimen with a black face, the main diagnostic feature that might be either an anomaly or result from postmortal changes in the specimen. It is this feature on which a cautious identification of a Mongolian specimen was based (Belyshev, Doshidorzhi, 1958). Moreover, E. I. Malikova examined this specimens and found it is Ae. juncea (personal communication). After 1961 (Belyshev, 1961) Russian sources, including Belyshev's works, did not mentioned for Mongolia such species as Sympetrum meridionale (Selys, 1841), Somatochlora graeseri and Ae. mixta, however, all they were later reported by G. Peters (1985). Included are also Sympecma gobica Forster, 1900 (is present in Table 6 in (Belyshev, Haritonov, 1981) but absent from the text devoted to Mongolia), Calopteryx virgo s.str., discovered recently in the Darkhan Hollow (Malikova, 1997) and two species of Ophiogomphus: O. reductus Calvert, 1898 and O. spinicornis Selys, 1878. The first was mentioned as "Ophiogomphus cecilia reductus" in (Belyshev, Haritonov, 1981) (for some reason it is absent from their list but mentioned in the text), but, as was found out by Krylova (Krylova, 1974), that communication was based on a report by K. Valle for "Khemchik", that is for the recent territory of Tuva Republic within Russia. Most probably it was in fact O. spinicornis. O. spinicornis was reported for Mongolia by Chao Chsy Fu (according to (Asahina, 1979)), but I am not sure it was not Inner Mongolia implied. However, I approve the presence of both species in Mongolia basing on the photographs, kindly provided by R. Seidenbusch, of the specimens collected in Mongolia by Prof. Peters and mentioned in his work (Peters, 1985) as Ophiogomphus serpentinus".The specimens from SW Mongolia (Bulgan, Dzhungarian Gobi) and W Mongolia (Uljastain-Go, Chovd gol tributary) are undoubtedly O. reductus, the females from N Mongolia (Selenga, Ich-nul steppes) is O. spinicornis. Besides, Peters (1985) for the first time reported for Mongolia Calopteryx splendens, Erythromma najas, Coenagrion puella (Linnaeus, 1758), Stylurus flavipes, Aeshna grandis (Linnaeus, 1758), Macromia amphigena Selys, 1871 (as M. sibirica Djakonov, 1926, the symomymy was stated by E. Malikova (1995), Somatochlora metallica, Libellula quadrimaculata and Leucorrhinia orientalis. Leucorrhinia rubicunda (Linnaeus, 1758) is given in the Table with "?" since this report may refer in fact to L. intermedia.

Since the book "The Grassland Insects of Inner Mongolia" [Ma Yao et al. 1991] is published in Chinese and is very little known, I find it worthy to reproduce here in full its records of dragonfly specie findings on the above territory adjacent to the Russian steppen Transbaikalia. Totally 14 species were reported that is evidently a very incomplete list (the full list of species mentioned for the entire Inner Mongolia contains 33 species, of which many are Manshurian elements). Lestes sponsa reported for Xin Barag Youqi, "Sympycna paedisca annulata Selys" (a correct spelling of the genus is Sympecma, most probably the authors had ssp. braueri - see above) - for Xin Barag Zuoqi, Xin Barag Youqi, Ergun Zuoqi, "Agrion virgo" (i. e. Calopteryx virgo, most probably it was C. japonica) - for Xin Barag Zuoqi, Chen Barag Qi, Aciagrion hisope Selys - for Xin Barag Zuoqi, Xin Barag Youqi, Chen Barag Qi, Ergun Zuoqi, "Coenagrion sexlineatum Selys" (now Cercion melanotum) - for Ergun Zuoqi, Enallagma cyathigerum - for Xin Barag Youqi, Ischnura senegalensis (Rambur) - for Xin Barag Zuoqi, Anax parthenope julius Brauer - for Xin Barag Youqi, Orthetrum albystilum - for Xin Barag Youqi, Sympetrum danae - for Chen Barag Qi , "S. frequens" - äëÿ Xin Barag Zuoqi, Xin Barag Youqi, Chen Barag Qi, S. imitans - for Xin Barag Zuoqi, Xin Barag Youqi, S. pedemontanum - for Xin Barag Zuoqi, Chen Barag Qi. In this list one should replace Sympetrum frequens with S. depressiusculum and Calopteryx virgo with Calopteryx japonica (see above). Cercion melanotum is included with "?" - as mentioned above, it is not excluded it was in fact Cercion v-nigrum. Note the absence of representatives pf Gomphidae and Corduliidae.

The four territories considered are very uneven in area, diversity of natural conditions, and degree of being studied. Surely, new pluses will appear in all the four columns with time. Let us suppose which species are expected to be found in the Daurian Reserve and the Onon valley.

The list of dragonflies of "the mountains of Transbaikalia" contains the following species not found by us: Calopteryx virgo (i.e. C. japonica (Ìàëèêîâà, 1995)), C. splendens (Harris, 1782), Nechalenia speciosa (Charpentier, 1840), Coenagrion concinnum (Johansson, 1859) (= C. johanssoni (Wallengren, 1894)), Coenagrion hylas (Trybom, 1889), Aeshna grandis, Ae. coerulea Stroemberg, 1783 (= Ae. squamata (Muller, 1754)), Ae. subarctica Walk., Gomphus epophtalmus Selys, 1872, Nihonogomphus ruptus (Selys, 1758), Ophiogomphus obscurus, Somatochlora alpestris (Selys, 1840), S. arctica (Zetterstedt, 1840), S. metallica (Van der Linden, 1825), S. sahlbergi Trybom, 1889, Cordulia aenea (Linnaeus, 1758), Orthetrum albistylum (Selys, 1842), Leucorrhinia orientalis Selys, L. dubia (Van der Linden, 1825) (if the latter was not in fact L. orietalis). Some of these species (S. alpestris, S. sahlbergi, and, in a less extent, S. arctica) are connected with highlands, they can hardly be found in the Daurian Reserva. O. albystilum is known in Siberia only from hot sources at the eastern bank of Lake Baikal (Belyshev, 1973) and the Chara Hollow (Belyshev et al., 1978), but is reported for a site in Inner Mongolia close to the Russian border (Ma Yao et al., 1991). Thanks to their wide ecological amplitude, such species can be quite expected to find out as Ae. grandis (if it goes eastwards so far), C. aenea and even N. speciosa, although the latter species is local and rare. In intrazonal biotopes of the Onon valley, with tree vegetation developed, or at Lake Betevken in the Tsasucheiskii Bor pine forest one can expect C. concinnum, C. hylas, Ae. subarctica, Ae. coerulea (little probable), C. aenea, L. orientalis. (It should be noted that C. concinnum, C. aenea and L. orientalis were found by us on 17^th June and 6^th July 1995 on a small semicurrent pool with boggy banks in an open larch/birch forest on a gentle pass of a road Darasun - Aginskoe through the Mogoituiskii mountain range, i.e. 100 km NW of Nizhnii Tsasuchei). The following rheophyls could quite inhabit the Onon River C. japonica, C. splendens, G. epophtalmus (a species with a very local distribution and so not very expectable), and N. ruptus (but hardly O. obscurus , which should be replaced with its close relative O. spinicornis). However, no specimen of these specimens was met with for three seasons.

The following species, not found by us, were reported for Mongolia: Sympecma gobica, Lestes macrostigma Eversmann, 1836, Coenagrion hylas, Coenagrion puella, Ishnura pumilio (Charpentier, 1825), Aeschna affinis Van der Linden, 1825, Aeshna grandis, Ophiogomphus reductus, Macromia amphigena, Orthetrum brunneum Fonscolombe, 1837, O. cancellatum (Linnaeus, 1758), Leucorrhinia orientalis, Sympetrum striolatum (Charpentier, 1840), S. tibiale Ris, 1897, S. fonscolombei (Selys, 1840), S. sanguineum (Muller, 1764), Sympetrum meridionale (Selys, 1841). On L. orientalis is said above. L. macrostigma, C. puella, Ae. affinis, Ae. grandis, O. reductus, O. cancellatum, S. fonscolombei, S. tibiale, S. sanguineum most probably inhabit only West Mongolia and so can hardly be found in Dauria. The presence of S. gobica, I. pumilio, M. amphigena and O. brunneum is questionable, since their range is insufficiently studied, while finding of S. striolatum and S. meridionale seems quite possible.

Of species reported for the above mentioned part of Inner Mongolia C. japonica, A. hisope, C. sexlineatum, I. senegalensis, O. albystilum were not found in Dauria. It is hard to judge whether some of them can penetrate into our territory, there is also a certain doubt in correctness of their identification.

It may be concluded from Table 1 that the fauna of the Daurian Reserve and surroundings of the village Nizhnii Tsasuchei resembles that of Mongolia. Among dragonflies found on the Onon River and Torei Lakes there are some species not reported so far for Mongolian People's Republic, namely, Cercion v-nigrum, Coenagrion glaciale, Erythromma najas, Anisogomphus maacki, Epitheca bimaculata, Somatochlora graeseri, Pantala flavescens. However, there is no doubt all these species must penetrate into the north of this country along the Mongolian section of the Onon River. Belyshev and Haritonov (1981) noted the poorness of the odonatofauna of East Mongolia lacking some species of the fauna of Dauria (implied as the steppen Transbaikalia and Amurland), including our Epitheca bimaculata, Somatochlora graeseri, Coenagrion lanceolatum, C. glaciale. Their inference would remain true if not to say not on Mongolia strictly within its state borders but rather include the Onon basin into Dauria and to consider as Mongolian the fauna of outflowless steppen plains of Mongolia (to which the depression of Torei Lakes should also be attributed). Note that some species known from Mongolia only from the Altai Mts. or the region of Lake Hubsugul should also be excluded from "a Mongolian fauna" per se.

It may be noted that the dragonfly aspect in the northern Ubsu-Nur Hollow, situated in South Tuva, i.e. as well at the Mongolian/Russian border but in its western part, physiognomically much resemble that of the Daurian Reserve and its environs (Zaika, Kosterin, 1992), although in the former case there were much less species found. This is due to a shorter time of observations in Tuva and the absence of such a major river as the Onon. Among species collected in South Tuva only Aeshna affinis was not found by us in Dauria (leaving aside the problem of conspecificity of S. vulgatum and S. imitans).

In the work by I. Haritonova (1990) the following species were not reported for the mountais of Transbaikalia: C. v-nigrum, I. elegans, A. mixta, A. serrata, A. parthenope, O. spinicornis, A. maacki, S. flavipes, P. flavescens. To my mind, Transbaikalia can not practically subdivided into the lowland and mountainous parts (in large areas it is just a hilly country), so it would be better to speak about Transbaikalia in general, from which it is now known as many as 49 species.

Conclusion

The dragonfly fauna of the Daurskii State Nature Reserve and its surroundings is rich and interesting. Two Manshurian species, namely, Cercion v-nigrum and Anisogomphus maackii, penetrate here from the East, a steppen species Aeshna serrata from the West, Ophiogomphus spinicornis, Pantala flavescens, Sympetrum depressiusculum from the South. The Onon River valley exhibits the most species richness where water bodies of various types are present while the river valley itself, with its intrazonal biotopes, serves as a channel through which a diverse dragonfly fauna penetrates into the steppen zone from the North-East.

We have made some important faunistic findings: the known ranges of Cercion v-nigrum and Anisogomphus maackii were extended much westerly, Ophiogomphus spinicornis is for the first time reliably recorded from the territory of Russia, the presence in Transbaikalia of Anax parthenope and Pantala flavescens is proved.

Noteworthy we found no representatives of the genera Orthetrum and Calopteryx, although both are present in the fauna of Transbaikalia (Haritonova, 1990), Mongolia (Belyshev, Haritonov, 1981), and Inner Mongolia (Ma Yao et al., 1991). The Onon River was investigated by us rather thoroughly and the presence of some Calopteryx within its section studied is unlikely. Some Orthetrum, as well as some other species, may be still found on some lakes of the Torei depression.

Acknowledgments

I express my deep gratitude to V. A. Brinikh, the director, and all the stuff of the Daurian State Nature Reserve for their hospitality and a great help and a partial financial support of the work. I am grateful to O.G. Berezina who so nicely shared with me a part of the field work. I am much grateful to all other collectors: V.V. Dubatolov, I. I. Lyubechanskii, A. Korolyuk, V. A. Brinikh. I am thankful to R. Seidenbusch, E. I. Malikova, R. Joedicke, Prof. A. Y. Haritonov, Prof. M. G. Sergeev for valuable consultation and help with literature, to V. V. Dubatolov for explanation of toponyms published in Chinese. My especial gratitude is to Prof. Z. Spuris for so valuable critically reading of the manuscript and for offering a possibility to publish this paper in a full length and to R. Seidenbusch for a financial support of this publication.

References