V. V. Dubatolov (*), O. E Kosterin (**)

In the second half of the summer in 1996 and 1997 large materials of butterflies were collected in the Argun' River basin (the extreme east of Siberia), earlier almost denied to access for entomological studies due to a severe frontier regime. In particular, we thorougly studied scarce woods of the Mongolian oak (Quercus mongolica) in the Budyumkan and Argun' River valleys south of the village Uryupino, which are the extreme western habitats and, at the same time, locus classicus (type locality), of this characteristic Manshurian tree species, probably isolated from its main range. We found 87 species of butterflies 47 of which are Transpalaearctic, 19 are East Palaearctic (Siberian-Far Eastern), 16 are East Asiatic (Palaearchearctic and Transbaikalian-Amurian), 2 are West Palaearctic (European-Siberian), and 3 are Amphipalaearctic. Eight East Asiatic species (Pyrgus (alveus) schansiensis, Pieris (napi) melete, Favonius taxila, F. ;cognatus, Celastrina ladonides, Apaura metis, Neptis thisbe, Araschnia burejana) are firstly reported for Chita Province and Siberia, three of which (F. ;taxila, F. ;cognatus, N. ;thisbe) are monophagous on the Mongolian oak. Besides, Mellicta plotina is firstly reported for the Chita Province. There are a transition zone between Hyponephele lycaon catalampra and H. ;l. ;Pasimelas; these two taxa should be considered at a subspecies rank. A short description of the pupa of Neptis thisbe is given for the first time.

KEY WORDS: Hesperioidea, Papilionoidea, fauna, Transbaikalia, Argun basin, Chita province, South Sibaria.

The fauna of Transbaicalia, especially of its eastern parts, includes a lot of species, the main ranges of which lies in East Asia, in the Palaearchaearctic Subprovince of the Palaearctic. In this respect the Argun' River basin (Russ. "Priargunye"), being the eastern extreme of Transbaikalia, is most reach of such species. There are westernmost localities of the Mongolian oak (Quercus mongolica Fischer ex Ledeb.) in the lower Argun' basin. This is an important characteristic species and ediphicator of Manshurian forest vegetation (Menitsky, 1982). Moreover, this is locus classicus of this tree (Flora Sibiri, 1992). So far information on butterfly fauna of these places was extremely scarce, only few species were reported by V. ;V. ;Chikolovets (1994) for Argunsk. The main territory of the Argun' basin was until recently completely denied for access due to a severe frontier regime in the Soviet times (the Argun' River divides Russia and China).

In 1996, thanks to an active promotion of a V. ;A. ;Brinikh, a Director of the State Nature Reserve "Daurskii" and a finantial support of the the Foundation of Baikal (Chita, T.A. Strizhova, head), a short trip was undertaken to this region on 7-15th August with the following route: Nizhnii Tsasuchei - Priargunsk - Kalga - Nerchinskii Zavod - Argunsk - Nizhnyaya Vereya - Mar'ino - Ust'-Lubiya - Uryupino and back, entomological studies being carried out by V. ;V. ;Dubatolov and V. ;A. ;Brinikh. The materials collected were so interesting that in 1997 a second expedition was held by the State Nature Reserve "Daurskii" with the route Nizhnii Tsasuchei - Aleksandrovskii Zavod - Akatui - Nizhnyaya Shakhtoma - Gazimurskii Zavod - Kurleya - Budyumkan - Uryupino - back to Gazimurskii Zavod - Nerchinskii Zavod - Kalga - Nizhnii Tsasuchei, supported financially by Prof. Tomoo Fujioka (Tokyo, Japan) and T. ;A. ;Strizhova (Foundation of Baikal). In this trip three entomologists took part, V. ;V. ;Dubatolov, O. ;E. ;Kosterin, O. ;G. ;Berezina. Authors are sincerely grateful to the two other collectors and to all the colleagues who participated on these expeditions and helped in their organization. We express gratitude to the officers of the frontier service of the Zabaikalskii Frontier Force, without whose help and good will these expeditions would be impossible. We are also grateful to Director of the Nerchinskii Zavod Forestry, who provided a valuable information on the situation of the oak groves in the Argun' Basin.

Unfortunately, both trips were in late summer and hence did not allow to reveal the fauna fully.

All the materials collected in 1996 and most of those collected in 1997 are preserved in the Siberian Zoological Museum (further - SZMN) at the Institute of Systematics and Ecology of Animas of Siberian Division of Russian Academy of Sciences, Novosibirsk, a part of collections of 1997 was transferred to Prof. T. ;Fujioka.

The region considered (Fig. 1) consists of the Argun' River basin north of 50° N to the Gazimur River lower reaches. Its southern part has a steppen vegetation, which is partly replaced with agricultural or long fallow lands in plains, while rather low mountains are covered with a luxuriantly flowering meadow steppe of a Dahurian type, with Filifolium sibiricum (L.) Kitam. among the dominants. As we proceed northwards, the meadow steppe retains on southern slopes, occupying gradually reducing area, while northern slopes are progressively occupied with birch and, more northerly, larch forests, so that the land acquires features of a typical taiga landscape. A larch taiga predominates in northern parts of the region, meadow steppen patches being scattered only on rather steep southern slopes at low altitudes. The dominant tree species, the Dahurian larch (Larix gmelinii (Rupr.) Rupr.), is everywhere mixed with the silver birch (Betula pendula Roth., =Betula verrucsa Ehrh., =Betula platyphylla Sukaczev) in different proportion, the latter sometimes even excluds the larch. The pine tree (Pinus sylvestris L.) is common everywhere, preferring hill crests and forest edges neighbouring with open places, where forms open stands. River banks are grown up with different willows (Salix), and, besides, the bircd cherry (Padus avium Miller) and alder (Alnus hirsuta (Spach) Turcz. ex Rupr.), which at higher altitudes is replaced with its derivative (Alnus x sibirica (Spach) Turcz. ex Kom.), resulting from intergradation of A. ;hirsuta and (Alnus (Dushekia) fruticosa Rupr.). The latter is numerous high in the mountains and even forms a pure elfin woods on major summits exceeding 1000 m above sea level. The trees mentioned make the landscape to have a typical Siberian appearance. However, East Transbaikalia is known as the transition zone between Siberian and Manchurian vegetation. At a first glance on the dot maps of plant species distribution in Flora of Central Siberia (1979) one is impressed with numerous Manchurian species which are found in Transbaikalia only in the Argun' River valley and its close vicinity. Visiting this places justifies the anticipations, abundance of Manshurian species arrests attention. Physiognomically the main change concerns appearance of the Dahurian birch (Betula davurica Pallas). Its branchy and spreading crawn resembles that of many broad-leaved tree species and differs strikingly from the majority of Siberian trees having a clearly expressed monopodial growth type. In the northern areas of the region the Dahurian birch grows by small groves on ledges and small gullies on open southern slopes and is admixed to the silver birch and larch on gentle places. In the vicinity of the settlement Nerchinskii Zavod it forms pure forests. In the upper herb layer attention is attracted first of all by large and numerous clumps of Dictamnus dasycarpus Turcz. and (Paeonia lactiflora Pallas). Noteworthy that these plants still absent, say, at the village Kurleya on the Gazimur River, are very abundant in very diverse biotopes at the village Uryupino on the Argun' River, from steppefied slopes to open mixed forests. Among less robust herbs there appear or become abundant many Eastern species, including such well-noticeable as Convallaria keiskei Moq., Smilacina dahurica Turcz. ex Ledeb., Cimicifuga dahurica (Turcz. ex Fischer et Meyer) Maxim., Cimicifuga simplex Wormsk., Lychnis fulgens Fischer, Viola variegata Fischer ex Link., Campanula punctata Lam., Platycodon grandiflorus (Jacq.) A. ;DC., Senecio flammeus Turcz. ex DC. Lastly, on mountain slopes on the Argun' valley left boars, between its left tributaries the Budyumkan and Uryumkan Rivers (and also on the left board of the Budyumkan River valley 5-7 km upstream of its mouth), the Mongolian oak (Quercus mongolica Fischer ex Ledeb.) appears. Its stands, pure or with participation of larch and silver and Dahurian birches and pines, are confined to southern slopes above 500 m above sea level. The oak is obviously depressed here, the trees are low, rarely exceeding 10 m (in mixed stands the oak is always in the second layer), all more or less old trees have a rotten pith, trees with acorns are extremely rare. Nevertheless, the oak actively occupies new area, as its young growth is constantly present in mixed birch/larch or pine/parch forests and on meadowy openings, including those situated many kilometres apart of the main oak massifs. Besides of the oak, in the low (up to 7 km of the mouth) Budyumkan River valley we found two small grows of another eastern broad-leaved tree speceis, Ulmus japonica (Rehder) Sarg.

For the sake of convenience the main localities, a list of which is given below, are designated by short words and expressions, as explained below:

Fig. 1. A scheme of the region studied. For explanation of sites see the beginning of the annotated list.

1. Ulan - hills and a pass of the road from Priargunsk to Byrka, 7 km NNW of the village Ulan, or 23 km NW from the settlement Priargunsk; a steppe.

2. Ildikan - the Ildican and Srednyaya Borzya Rivers interfluve 15-18 km ENE of the village Kalga; a steppe and rocky mountain slopes

3. Alekzavod - western environs of the village Aleksandrovskii Zavod; forest-steppe and valley meadows.

4. Akatui - a larch taiga on the mountains being the junction of the Uryumkanskii and Kukul'bei mountain ranges along the road Novyi Akatui - Vershino-Shakhtominskii.

5. Unda - the Unda River upper flow (the Shilka River basin) at the Nizhnyaya Shakhtoma River mouth, at the village Nizhnyaya Shakhtoma, bank meadows and willow and alder thickets.

6. Nerzavod - 5 km S of the village Nerchinskii Zavod, mostly steppefied meadow on the southern slope, also (if specified) edges of the Dahurian birch woods and a damp meadow on a brook valley.

7. Solontsy - a damp meadow at the Urov River headwaters at the village Solontsy, 38-40 km ESE from the village Gazimurskii Zavod.

8. Gazzavod - 12 km SW of the village Gazimurskii Zavod, 2 km SW of the village Dog'e, forb meadows, edges of a silver birch forest and a cutting in it on SE-exposed slope.

9. Argunsk - 3 km downstream of the village Argunsk, 45 km NE from the village Nerchinskii Zavod; steppefied rocky mountain slope and a long fallow land with ruderal vegetation at its foot.

10. Serednyaya - the frontier post Serednyaya, 15 km NNE from the village Argunsk; steppefied meadows.

11. Zapisina - the upper part of the Zapisina Pad' valley, 27-30 km NE from the village Argunsk; a brook valley with arboreal alder stand; a forest road.

12. Vereya - the frontier post Nizhnyaya Vereya, 30-33 km NE from the village Argunsk; long fallow lands.

13. Vereya mts. - a mountain range, several km NE of Nizhnyaya Vereya; larch forest with Vaccinium vitis-idaeus.

14. Kurleya - the Gazimur River right bank at the village Kurleya, 90 km NE from the village Gazimurskii Zavod; damp meadows and willow thickets.

15. The mine - an old mine in the valley a left tributary of the Budyumkan River 30 km upstream the village Budyumkan; mine debrices, rosky slopes, larh taiga.

16. Lubiya - environs (2-3 km S) of the frontier post Ust'-Lubiya, 25 km SE from the village Uryupino; larch taiga on rocky mountain slopes, a forest road.

17. Uryumkan - a bridge over the Uryumkan River, several km up from its mouth.

18. Argun' bend - a pass of the taiga mountains on the left board of the Argun' valley in front of its right bend at the joint of Ust'-Lubiya and Uryupino frontier sections, between the Uryumkan and Budyumkan river valleys; larch taiga with participation of Daurian birch, a wide stony road.

19. Polovinnaya - the Polovinnaya Pad' valley (if specified) and its left board (by default), at the travers of 161-163th km alignment of the Argun' River, 10 km S of the village Uryupino; a damp valley and its steppefied left board, partly covered with a mixed larch/birch/pine forest with participation of Mongolian oak.

20. Argun' valley - gentle easterns slope of the mountains at the Argun' River left bank south the Budyumkan River, 5-7 km S of Uryupino, open birch/larch/pine forests with participation of Mongolian oak.

21. Argun' bank - the Argun' River left bank at 160-161 km alignment, about 10 km S of the village Uryupino.

22. Budyumkan - the Budyumkan River valley left board 5-7 km upstream of its mouth, open meadow steppen slopes and open pine / Dahurian birch / larch / Mongolian oak stands, if specified - a damp floodland meadow.

23. Budyumkan mouth - the Budyumkan River valley, 0-5 km upstream of its mouth.

24. Village Budyumkan - the village Budyumkan environs, at the road to Kaktolga; floodland with meadows and willow thickets, sometimes with mixed larch/birch/pine forests.

25. The brook - a brook in a larch taiga between the villages Budyumkan and Uryupino, 7 km NE of the former.

26. 2^nd valley - a frontier service road crossing the 2^nd woody brook valley descending from the mountains at the Argun' River left bank downstream of the village Uryupino, 15 km NE of it; mixed larch/birch forest.

27. 3^rd valley - a frontier service road crossing the 3^rd woody brook valley descending from the mountains at the Argun' River left bank downstream of the village Uryupino, 19 km NE of it.

28. Gazimur - the Gazimur River right bank at its winding in the low flow about 10 km above the mouth, at a bridge; mixed larch/birch/pine forests and an open rocky mountain slope.

Sites of occasional collections are written fully in the materials.

Abbreviations in the materials lists: $ - male(s), # - female(s), spm - specimen(s), vo - visual observations. The species for the first time reported for Transbaikalia are preceded with asterisks (*).

Pyrgus (alveus) speyeri (Staudinger, 1887). An East-Palaearctic species common throughout Eastern Transbaikalia from steppes to taiga, sometimes being confused with a close species P. alveus Hbn., s. ;str. (Plyushch, 1992; Kostyuk et al., 1994), penetrates as north as Megino-Aldan in Eastern Yakutia (Megino-Aldan, materials of SZMN and Yakutsk Institute of Biology of Yakutsk Branch of Siberian Division of Russian Academy of Sciences). By genitalia structure our specimens are similar to those from Primorye (Fig. 2, 3). The males of this species differ from P. alveus Hb. by the apical processus of the harpe being much longer, from the following species - by this processus being smoothly curved in its basal half.

Inhabits meadows and openings in taiga.

Materials. Unda, 23.VII.97 - 1 $; Nerzavod, 6.VIII.97 - vo; Solontsy, 5.VIII.97 - 1 $ 1 #; Gazzavod, 24.VII.97 - 1 $; Zapisina, 13.VIII.96 - 1 $; the mine, 4.VIII.97 - 1 $; Lubiya, 11.VIII.96 - 1 $; Argun' bend, 11.VIII.96 - 3 $; Polovinnaya, 29.VII.97 - 1 $; the brook, 25.VII.97 - 2 $.

*Pyrgus (alveus) schansiensis Reverdin, 1915. A Manshurian species for the first time found in Siberia. It is described from Central China, later found by M. ;G. ;Sergeev in Primorye and by A. Streltsov (1995) in the Amur Province. Inhabits meadows, our specimens were found on the floodland ones. In this species the upper processus of the harpe is bent only at the base and further is more or less straight and situated at a noticeable angle to the cucculus upper margin (Fig. 4, 5). The male genitalia in our specimens proved to be identical with the drawing at the original description (Reverdin, 1915).

Materials. Nerzavod 6.VIII.97 - 1 $; Budyumkan mouth, 26.VII, 1.VIII.97 - 2 $, 1 #.

Heteropterus morpheus (Pallas, 1771). A Transpalaearctic species common in South-Eastern Transbaikalia. Nevertheless we found only one specimen, most probably due to rather late period of work. Inhabits meadows, mostly valley and floodland ones.

Materials. Kurleya, 5.VIII.97 - 1 #.

Thymelicus lineola (Ochsenheimer, 1808). A Transpalaearctic species common everywhere on valley meadows.

Materials. Ildikan, 9.VIII.96 - 1 #; Alekzavod, 22.VII.97 - 1 $; Unda, 23.VII.97 - 1 $; Nerzavod, 6.VIII.97 - 1 #, vo; Solontsy, 5.VIII.97 - 1 #; Gazzavod, 24.VII.97 - 2 #; Budyumkan, 26.VII.97 - 1 #.

Hesperia (comma L.) florinda rozhkovi (Kurentzov, 1970). A species ranging from Transbaikalia through Amurland to Japan, inhabits meadows, mostly steppefied.

Materials. Ildikan, 9.VIII.96 - 2 #; Unda, 23.VII.97 - 4 $, 4 #; Polovinnaya, 28.VII.97 - 1 #; Budyumkan, 11.VIII.96 - 1 #; 26-27.VII.97 - 2 $, 1 #; Gazimur, 31.VII.97 - 1 #.

Ochlodes (venatus (Bremer et Grey, 1852)) sylvanus (Esper, 1779) ssp. A Transpalaearctic species inhabiting meadows and forest openings. Due to a late time of work it was met with very rarely. For notes on the name used see page 143 of this edition: ("As recent studied showed, an Amurian/Manshurian species Ochlodes venatus [Bremer et Grey, 1852) well differs from a widely distributed Palaearctic species called by different authors either O. hyrcana Christoph, 1893 (Tuzov, 1993) or O. ;faunus (Turati, 1906) (Korshunov & Gorbunov, 1995; Devyatkin, 1997) or even as two species, O. hyrcanus and O. similis (Fujioka et al., 1997). The formerr, as it was convincingly shown by H. ;Hauser (1982), is an good species ranging locally at the southern coast of the Caspian Sea along the northern slope of the Elburs Mts. from Talysh to SW Kopet-Dagh. To our mind, two other names refer to the same species enjoing a contiguous transpalaearctic range. Its oldest name, Papilio sylvanus Esper, 1779, is a homonym. However, A. D. Devyatkin (1997) has submitted a proposal to the International Comission for the Zoologocal Nomenclature to preserve the name Ochlodes sylvanus (Esper, 1779)"].

Materials. Gazzavod, 24.VII.97 - 1 $; Polovinnaya, 28.VII.97 - 1 #.

Parnassius nomion (Fischer de Waldheim, 1823). An East-Palaearctic species. Reported by V. V. Chikolovets (1994) for the village Shara (Nerchinskii mt. range). We met it in many places but by few specimens on steppefied meadows and meadow steppes, mostly on southern slopes.

Materials. Ulan, 8.VIII.96 - 1 #; Alekzavod, 22.VII.97 - 2 $; Unda, 23.VII.97 - 1 $; Nerzavod, 6.VIII.97- 1 #; a meadow at the road between the villages Nizhnyaya Shakhtoma and Gazimurskii Zavod, 23.VII.97 - 1 $; Gazzavod, 24.VII.97 - vo; Budyumkan, 26.VII.97 - 1 #, 4.VIII.97 - v; the brook, 25.VII.97 - 1 #.

Papilio machaon Linnaeus, 1758. A common Transpalaearctic species without noticeable biotope preference. Reported by V. V. Chikolovets (1994) for the village Shara.

Materials. Ulan, 8.VIII.96 - 2 $; Ildikan, 9.VIII.96 - vo; Nerzavod, a brook valley, 9.VIII.96 - 1 # + vo, 14.VIII.96 - 1 #; Serednyaya, 10.VIII.96 - vo; Budyumkan, 26.VII.97 - 2 $; the brook, 1-2.VIII.97 - 1 #.

Sinoprinceps xuthus (Linnaeus, 1767). An East-Asiatic species, proposed for protection in Chita Province. All the old records from Transbaikalia concerned capture or observation of single specimens (in Kyra, Gulzhenga by SZMN collection, in Argunsk (Chikolovets, 1994)). In more steppen parts of the region considered these buttreflies were extremely rare, they keeped to most prominent heights serving as sites of sex neetings, but only males were collected. The maximum abundance of this species was observed by us in the forest-steppen environs of Nerchinskii Zavod on 9th August, 1996, where for an hour more than 20 specimens could be met with! When we revisited this site on 14th August its abundance had fallen considerably (few specimens for an hour), that might be explained by their moving anywhere. In the forest areas of the 1996 route the species was observed to be much less abundant (about 1 specimen per 10 km observed from the car), the butterflies keeping to open habitats. In 1997 this butterfly appeared to be rare at Nerchinskii Zavod, for 6th August we met with only about 5 specimens, that was about the same density as in the woody Argun' valley on August 26-311997.

It should be noted that the main foodplant of this species in Primorye, Phellodendron amurense Rupr., is completely absent from Transbaikalia, but a supplementary foodplant, Dictamnus dasycarpus and some Apiaceae (the senior author observed oviposition of S. ;xuthus on Apiaceae plants at Ryazanovka in Southern Primorye) are present in abundance. D. ;dasycarpus is extremely abundant in Argunian Dahuria and is reported also for the Onon valley (Flora of Central Siberia, 1979). On 31st July 1997 we observed oviposition of a female S. xuthus on D. ;dasycarpus in an open larch/birch forest with a participation of Mongolian oak southwards of the Budyumkan River lowest reaches.

Materials. Ulan, 8.VIII.96 - 1 #, 2 spm (vo); Nerzavod, 9.VIII.96 - 10 spm, several dozens specimens visually; 14.VIII.96 - 5 spm; 6.VIII.97 - 1 $ 1 #; Argunsk, 10.VIII.96 - 3 spm (vo); Serednyaya, 10.VIII.96 - 1 $; Zapisina, 10.VIII.96 - 1 $ + 3 spm (vo); Vereya, 10.VIII.96 - 1 $; Lubiya, 11.VIII.96 - 1 $; between the frontier posts Ust'-Lubiya and Uryupino, 11.VIII.96 - 4 spm (vo); Polovinnaya, 28.VII.97 - 1 #; 29.VII.97 - 1 $; Budyumkan, 26.VII.97 - 1 $, 1 #; 2^nd valley, 31.VII.97 - 1 $.

-Achillides maackii (Menetries, 1859). An East-Asiatic species reported by visual observations only for Eastern Chita Province (Amazar, Nizhnii Tsasuchei) (Chikolovets, 1994). Search for this species in the Argun' valley was one of the aims of our expeditions, however, we failed to find it. Majority of our local informers (persons with a long experience of local nature: forest officers, hunters, soldiers, etc.) said that they definitely used to observe butterflies corresponding to our description, but extremely rarely - no more than once a yearIt should be noted that in Primorye the larvae of this species feed on Phellodendron and extremely rarely develop on a relative plant genus Dictamnus (Kurentzov, 1970). . Most probably this buttefly do occur in Eastern Transbaikalia but only as long migrating specimens and not develops there.

Leptidea morsei (Fenton, 1881). A Transpalaearctic species; according to our observations it is rare in Transbaikalia, as different from the next one. Inhabits damp and forest meadows.

Materials. Akatui, 23.VIII.97 - 1 #; Nerzavod, 6.VIII.97 - 1 $; the brook, 25.VII.97 - 1 $.

Leptidea amurensis (Menetries, 1859). An East-Palaearctic species abundant everywhere, keeps to open places, mostly dry and steppefied meadows. Reported for the village Shara (Chikolovets, 1994).

Materials. Ulan, 8.VIII.96 - 2$, 2 #; Ildikan, 9.VIII.96 - 1 spm; Unda, 23.VII.97 - 1 $; Nerzavod, a brook valley, 9.VIII.96 - 4 spm; 6.VIII.97 - 3 $, 1 #; Solontsy, 5.VIII.97 - 1 $, 1 #; Argunsk, 13.VIII.96 - 1 #; Zapisina, 13.VIII.96 - 1 #; Kurleya, 5.VIII.97 - 1 $; Lubiya, 11.VIII.96 - vo; Argun' bend, 11.VIII.96 - 1 $; Budyumkan, 11.VIII.96 - vo; 26.VII.97 - 1 $; village Budyumkan, 25.VII.97 - 1 $; the brook, 25.VII.97 - 1 $.

Aporia crataegi (Linnaeus, 1758). A Transpalaearctic species, probably, one of the commonest but met with only once due to an earlier flight period.

Materials. village Budyumkan, 25.VII.97 - 1 $.

Synchloe callidice (Huebner, 1805). A montane steppen Transpalaearctic species. Reported by V. V. Chikolovets (1994) for Argunsk (22^nd July 1993). Not found by us.

Pieris dulcinea Butler, 1822. A Transbaikalian-Amurian species, relatively rare although ranging throughout the Chita Province from the Kodar Mts. in the north to Russian-Mongolian border near the Torei Lakes in the south (SZM materials). As different from Pieris melete,. the two black spots on the fore wing underside are similar in size. The only specimen was found on a meadow at an edge of a Dahurian birch grove on a bank of a swamped brook.

Materials. Nerzavod, a brook valley, 6.VIII.97 - 1 $.

*Pieris ?melete orientis Oberthьr, 1880. A species ranging from Amurland to Japan, for the first time found in Transbaikalia. In this species on the fore wing underside the hind black spot is much larger than the fore one. The only specimen was collected just in the same point as that of the previous species but an year before. Presence of two different species of the P. ;napi (Linnaeus, 1758) and rarity of both are noteworthy.

Materials. Nerzavod, a brook valley, 9.VIII.96 - 1 #.

Colias hyale pallidis Fruhstorfer, 1910. An European-Siberian species common in the steppen and forest-steppen areas of the Argun' basin, probably at the eastern border of its range not trespassing the Great Hingan Mts. The butterflies inhabit meadows and meadow steppes.

Materials. Ulan, 8.VIII.96 - vo; Ildikan, 9.VIII.96 - 1 $; Nerzavod, a brook valley, 9 s, 14.VIII.96 - 3 $, 2 #; 6.VIII.97 - 2 $, 1 #; Argunsk, 13.VIII.96 - vo.

Colias erate f. poliographus Motschulsky, (1861). A Transeuroasian species, in general rare and local in Transbaikalia: two reliable records exist, the Kyra environs (in 1991) and woody left-bank mountains of the Argun' valley (in 1996).

Materials. Zapisina, 13.VIII.96 - vo; Argun' bend, 11.VIII.96 - 1 $.

Colias palaeno orientalis Staudinger, 1892. A Transpalaearctic species, probably quite common in the taiga zone. Interesting is a finding (9th July 1996) of a female of this species in a meadow steppe at the mountain Tsagan-Obo (985 m above sea level, 20 km WSW of the settlement Sherlovaya Gora) on the Adon-Chelon moderate elevation situated within the steppe zone, with only tiny groves of birches or asps in shelters at northern foots of relic granite rocks crowning the crest of the elevation. In the Argun' basin the butterflies were collected in a valley of a small brook on the Gazimurskii Mt. Range covered with birch/larch forests. Reported for Argunsk (22^nd July 1993) (Chikolovets, 1994).

Materials. The brook, 25.VII.97 - 2 $, 3 #.

Colias chrysotheme andre Hemming, 1933 (=sibirica Grum-Grshimailo, 1893). An European-Siberian species characteristic to steppes where is common. Recorded once in a steppen area of the Argun' basin.

Materials. Ulan, 8.VIII.96 - vo.

Colias heos (Herbst, 1792) (=aurora Esper, (1781)). An East-Palaearctic species of meadow steppes. We met it with only twice, probably due to an earlier main flight period. Reported for Shara and Argunsk (Chikolovets, 1994).

Materials. Ulan, 8.VIII.96 -vo; Unda, 23.VII.97 - 1 #; Budyumkan, 26.VII.97 - 1 #.

Neozephyrus japonicus regina (Butler, 1881) (=taxila auct.). A Palaearchaearctic species. The "Green Zephyrus" group, to which this and next species belong, are classical representatives of the Far East (or Palearchaearctic, or Manchurian) fauna. They live high in tree crawns and so are hard to collect. They are characterized by a substantial sexual dimorphism, the wing upperside in males being bright glittering, green or blue, while in females it is brown, sometimes with light spots or glittering brands. They may be regarded as the beautest butterflies of Russia. The only species of this group, N. ;japonicus (Murray, 1875), was so far reported for Transbaicalia by a small series collected in 1929-1930 at Sretensk (materials of Zoological Institute of Russian Academy of Sciences, St.-Petersburg). We discovered two more populations of this species. The first was found in 1996 in the upper part of the Zapisina Pad' valley (the Argun' River basin) where the butterflies were collected in crowns of alder Alnus hirsuta, a foodplant of this species. The second was found in the Unda River upper flow (the Shilka River basin). In spite of thorough search on the alder, which is quite common everywhere in the forest zone of the region along brooks and rivers, no more sites inhabited by this butterflies were found. The species is proposed for protection in the Chita Province.

Materials. Unda, 23.VII.97 - 3 $, 2 #; Zapisina, 10.VIII.96 - 2 $, 2 #.

*Favonius taxila (Bremer, 1861). A Palaearchaearctic species, new for Siberia. As all the species of the genus Favonius Sibatani et Ito, this is monophagous on the oak. Although species of this genus are abundant in Amurland and Primorye, their presence in te Chita Province were doubtful , as no collections existed from the oak localities so far. Populations of Quercus mongolica in the Chita Province are most probably isolated from the main range since this tree has not been reported so far from the north of the Great Hingan Mts. (Tsiang et al., 1957), while upstream the Amur River the oak ranges only up to Albazino, where presents only in a shrub form, whereas a tree form does not occur upstream of the Humaerhe River mouth (Maack, 1859). This probable isolation of the oak in Transbaikalia seems to exist not less than several thousand years, since the climatic optimum of Holocene (a border between Atlantic and Subboreal periods), when it occured throuhout Transbaikalia west to Tunkun hollow (Belova, 1985) and in North-Eastern Mongolia along the Uldz-Gol River (Vipper et al., 1978). Fortunately, thorough examination of oaks south of Uryupino revealed the zephyrs, although not being abundant (several specimens of this and the next species were possible to observe for a day). Probably a shift of the flight period of these species and that of the sexes in both were reasons that on 27-30th July 1997 we have collected only males of this species and only fe males of the next one.

Materials. Polovinnaya, an oak forest, 28.VII.97- 2 $; the southern slope of the 2^nd brook valley descending from the mountains at the Argun' River left bank south the Budyumkan River, 10 km S of Uryupino, an oak forest, 30.VII.97 - 1 $.

*Favonius cognatus (Staudinger, 1892). A Palaearchearctic species, as the previous one for the first time being reported here for Siberia. It is connected with natural forests of the Mongolian oak.

Note. Accrding to lectotype designation, Favonius cognatus Stgr. became a senior synonym of F. ;latitasciatus ussuriensis Murayama, 1960 (=vitjaz Dubatolov et Sergeev, 1982) (Matsuda, 1996).

Materials. Polovinnaya, an oak forest, 12.VIII.96 - 2 #; 28.VII.97 - 1 #; 29.VII.97 - 3 #; the southern slope of the 2^nd brook valley descending from the mountains at the Argun' River left bank south the Budyumkan River, 10 km S of Uryupino, an oak forest, 30.VII.97 - 1 #.

Both Favonius species found range most widely throughout the area occupied by the Mongolian oak, reaching even the Selemdzha River in the north where they were found by A. ;V. ;Sviridov (materials of the Zoological Museum of Moscow state university, V. ;V. ;Dubatolov determinations). Due to locality and aesthetic value both species must be protected in the Chita Region.

There migh be found another zephyr species, Japonica lutea Hw, on oaks of Eastern Transbaikalia, which is widely distributed in the Amur Region. This yellow butterfly is well noticeable, but its flight period finishes in July and we might be late for it. It was reported for Xin Barag Zuoqi at Lake Dalainor in Inner Mongolia, China (Ma et al., 1991) just at the eastern border of Mongolian People's Republic, that is much westerly than our site. Most probably J. ;lutea reaches this locality following a Chinese rather xerophyte oak species Quercus wutaishanica H. ;Mayr, with the North-Western extreme of its range at Lake Dalainor (Menitsky, 1982).

Nordmannia prunoides (Staudinger, 1887). An East-Palaearctic species, rather rare on the territory considered, found on dry valley slopes in the forest zone, where its foodplant Spiraea grows.

Materials. Zapisina, 10.VIII.96 - 1 #; Polovinnaya, 29.VII.97 - 1 #; Budyumkan, 26.VII.97 - 1 #; Gazimur, 31.VII.97 - vo.

Thersamonolycaena dispar aurata (Leech, 1887) (=dahurica Graeser, 1888). A Transpalaearctic species inhabiting mostly damp floodland meadows. Reported for Argunsk (22^nd July 1993) (Chikolovets, 1994).

Materials. Nerzavod, a brook valley, 9.VIII.96 - 1 $; Solontsy, 5.VIII.97 - 1 spm; the brook, 25.VII.97 - 1 #.

Heodes virgaureae virgaureola (Staudinger, 1892). A Transpalaearctic speceies preferring dry meadows, rather infrequent in Easpern Transbaikalia.

Materials. Unda, 23.VII.97 - 1 $; Nerzavod, a brook valley, 6.VIII.97 - 1 #; Nerzavod, meadow-steppen slope, 6.VIII.97 - vo; Gazzavod, 24.VII.97 - 1 $;.

Heodes hippothoe (Linnaeus, 1761), ssp. A Transpalearctic species, prefering wet meadows and forest fields.

Materials. Unda, 23.VII.97 - 1 $.

Niphanda fusca (Bremer et Grey, 1852). A Palaearchearctic species reaching Transbaikalia. For Eastern Transbaikalia it was first recorded by L. ;Graeser (1888) at Pokrovka (just at the confluence of the Argun' and Shilka Rivers), then mentioned by A. ;K. ;Moltrecht (1929), and collected by M. ;G. ;Sergeev (1988) at Nerchinsk. Y. ;N. ;Baranchikov (1979) discovered this species as westerly as at Temnik on the southern slope of the Khamar-Daban mountain range (Buryatia). Reported for Argunsk and Nerchinskii Zavod (22^nd July 1993) (Chikolovets, 1994). We found it also in the Onon River valley at the village Nizhnii Tsasuchei, where this species was numerous in late June/July (observations of 1995-1997) in the thiskets of Ulmus macrocarpa Hance, U. ;pumila L. and Armeniaca sibirica (L.) Lam. on a rocky left bank of the Onon, much less frequently in its floodland. In the Argun' basin we collected two females on a steppefied meadow and in open mixed forest (with participation of the Mongolian oak) on the left board of the Budyumkan River valley.

Materials. Budyumkan, 26.VII.97 - 2 #.

Everes argiades (Pallas, 1771). A Transpalaearctic species common on various meadows and openings.

Materials. Ulan, 8.VIII.96 - 1 #; 15 km S of the village Kalga, 8.VIII.96 - 1 $, 3 #; Nerzavod, a brook valley, 9.VIII.96 - 6 $; 6.VIII.97 - 1 $; Argunsk, 13.VIII.96 - 1 #; Zapisina, 10, 13.VIII.96 - 5 $; Argun' bend, 11.VIII.96 - 1 #; 1.VIII.97 - 1 #; Polovinnaya valley, 28.VII.97 - 1 $; Argun'valley, 1-2.VIII.97 - 1 $; Budyumkan, 11.VIII.96 - 1 $, 6 #.

Tongeia fischeri (Eversmann, 1843). An East-Palaearctic species inhabiting petrophyte associations with Orostachys, usually on barren, mostly steppefied slopes.

Materials. Nerzavod, 14.VIII.96 - 1 spm; Gazzavod, 24.VII.97 - 1 #; Argunsk, 13.VIII.96 - 1 spm; Serednyaya, 10.VIII.96 - 1 spm; Zapisina, 13.VIII.96 - 1 spm.

*Celastrina ladonides (de l'Orza, 1867). An East Asiatic species, for the first time found in Siberia. It differs from a close C. argiolus (Linnaeus, 1758) by a presence of a small tooth at the base of the apical processus of the valve in the male genitalia (Fig. 6). Our specimen is identical to those from Primorye by this character. It was found in a mixed forest with participation of the Mongolian oak in an upper part of the left board of the Budyumkan River valley.

Materials. Budyumkan, 26.VII.97 - 1 $.

Glaucopsyche lycormas (Butler, 1886) ?lederi (A. Bang-Haas, 1907). An East-Palaearctic species. Thanks to a rather late period of work we found no males and so can't state a subspecies attribution.

Materials. Polovinnaya, 12.VIII.96 - 1 #; 28.VII.97 - 1 #; village Budyumkan, 25.VII.97 - 1 #; Gazimur, 31.VII.97 - 1 #.

Maculinea arion cyanecula (Eversmann, 1848). A Transpalaearctic species. Reported for Argunsk (22^nd July 1993) by V. V. Chikolovets (1994), not found by us.

Maculinea teleius obscurata (Staudinger, 1892). A Transpalaearctic species. It is comon but not abundant on meadows with Sanguisorba officinalis L., which is a foodplant for young larvae (later developing in nidi of Myrmica. ants). This species was never found on thickets of a close plant species Sanguisorba parviflora (Maxim.) Takeda, usual on wet floodlands.

Materials. Solontsy, 5.VIII.97 - 1 $; Argun' valley, 27.VII.97 - 1 $; Budyumkan mouth, 1.VIII.97 - 1 $.

Maculinea kurentzovi Sibatani, Saigusa et Hirowatari, 1994. A Transbaikalian-Amurian species rarely occuring on meadow hanitats with Sanguisorba officinalis. It should be noted that in the SZMN collection there is a specimen of this species collected at Agakan (the Khakass Republic) on 21^st July 1974, that is a so far known its westernmost locality

Materials. 15 km S of the village Kalga, 8.VIII.96 - 1 $; Polovinnaya, 28.VII.97- 1 $.

- Maculinea nausithous (Bergstrasser, 1779). This West-Palaearctic species was reported by V. ;V. ;Chikolovets (1994) for Amazar. We think it was a misidentification, since dark females of Maculinea teleius Brgstr. occur in Transbaikalia, which can be confused with M. ;nausithous Brgstr. Japanese entomologists (Sibatani et al., 1994) even doubted in M. nausithous presence in Siberia at all. But our data evidence for it to be common in the southern Siberia eastwards to Krasnoyarsk (materials of SZM) and is present in the Angara River basin (materials of Zoological Institute, St.-Petersburg).

Maculinea alcon (Denis et Schiffermьller, 1775). A Transpalaearctic species very rare in Transbaikalia, found on meadows.

Materials. Gazzavod, 24.VII.97 - 2 $, 1 #.

Lycaeides argyrognomon transbaicalensis (Kurentzov, 1970). A common Transpalaearctic species inhabiting meadows and forest openings.

Materials. Ulan, 8.VIII.96 - 2 $, 2 #; Akatui, 23.VIII.97 - 1 $; Nerzavod, a brook valley, 9.VIII.96 - 1 $; Gazzavod, 24.VII.97 - 1 $, 3 #; Zapisina, 13.VIII.96 - 1 #; Argun' bend, 11.VIII.96 - 1 $, 4 #; Polovinnaya, 28.VII.97 - 2 #; Argun' valley, 30.VII.97 - 1 #; Budyumkan, 11.VIII.96 - 2 #; 26.VII.97 - 1 $, 2 #; the brook, 25.VII.97 - 3 #; Gazimur, 31.VII.97 - 1 $.

Lycaeides subsolanus cleobis (Bremer, 1861). An East-Palaearctic species flying together with the previous one but somewhat less frequently. Reported for Shara and Argunsk (Chikolovets, 1994).

Materials. Unda, 23.VII.97 - 4 $; Zapisina, 13.VIII.96 - 1 #; Lubiya, 11.VIII.96 - 1 $, 2 #; Argun' bend, 11.VIII.96 - 1 #; Uryumkan, 11.VIII.96 - 1 #; Budyumkan, 11.VIII.96 - 1 $, 11 #, 26.VII, 1-2.VIII.97 - 2 $, 2 #.

Plebejus argus clarasiatica (Verity, 1931). A Transpalaearctic species common in West and Central Siberia but rare in the Chita Province. The only specimen was found on a mossy bogged valley of a small forest rivulet.

Materials. Polovinnaya valley, 28.VII.97 - 1 $.

Vacciniina optilete sibirica (Staudinger, 1892). A Transpalaearctic species common in the taiga zone in mossy forests, damp meadows and bogs.

Materials. Akatui, 23.VIII.97 - 2 #; a pass through the same mountains above tree line covered with the bush alder, 23.VII.97 - 1 $, 1 #; Zapisina, 13.VIII.96 - 2 #; Vereya mts., 10.VIII.96 - 4 #; Uryumkan, 11.VIII.96 - 1 #; Polovinnaya, 28-29.VII.97 - 4 #; Argun' valley, 30.VII.97 - 1 $; Budyumkan, 26.VII.97 - 1 #; the brook, 25.VII.97 - 1 #; 3^rd valley, 31.VII.97 - 3 #.

Eumedonia eumedon (Esper, 1780). A Transpalaearctic species probably rare in the Argun' Basin, pertained mostly to floodland or other damp meadows.

Materials. Alekzavod, 22.VII.97 - 1 #; Unda, 23.VII.97 - 1 #.

Aricia allous strandi Obraztsov, 1935. A Transpalaearctic species, as the previos one, keeping to damp, rarely mesophytous meadows but being much more abundant. Reported for Shara (Chikolovets, 1994).

Materials. Unda, 23.VII.97 - 1 $; Nerzavod, a brook valley, 9.VIII.96 - 1 $; Gazzavod, 24.VII.97 - 1 #; Zapisina, 10.VIII.96 - 1 $; Polovinnaya, 29.VII.97 - 1 $; Polovinnaya valley, 28.VII.97 - 1 #.

Albulina orbitulus pheretimus (Staudinger, 1892). A northern Transpalaearctic species whose range has most probably a disjunction in the northern East Europe. Reported by V. V. Chikolovets (1994) for Shara (Nerchinskii Mt. Range) as A. atys (Hbn.); not found by us.

Cyaniris semiargus pavlovi (Kurentzov, 1970). A Transpalaearctic species, probably rather common in early summer on meadowy (mostly dry) habitats. Reported for Shara (Chikolovets, 1994).

Materials. Unda, 23.VII.97 - 1 #; Lubiya, 11.VIII.96 - 1 #.

Plebicula amanda (Schneider, 1792). A Transpalaearctic species common on various meadows and openings.

Materials. Unda, 23.VII.97 - 1 $; Gazzavod, 24.VII.97 - 1 #; Budyumkan mouth, 26.VII, 1.VIII.97 - 1 $, 2 #.

Polyommatus icarus (Rottemburg, 1775). A Transpalaearctic species common on various meadows.

Materials. Alekzavod, 22.VII.97 - 1 $; Unda, 23.VII.97 - 2 $; Nerzavod, a brook valley, 6.VIII.97 - 2 $; Kurleya, 5.VIII.97 - 1 #; the brook, 25.VII.97 - 2 $; Gazimur, 31.VII.97 - 1 $.

Polyommatus erotides (Staudinger, 1892). An East-Palaearctic species pertained to dry meadows and steppes. Reported for Argunsk (22^nd July 1993) (Chikolovets, 1994). The Argun' basin is the eastern extreme of its range which, probably, does not trespass the Great Hingan Mts.

Materials. Ulan, 8.VIII.96 - 1 $; Ildikan, 8.VIII.96 - 1 $; Alekzavod, 22.VII.97 - 3 $, 1 #; Nerzavod, a brook valley, 9.VIII.96 - 1 $; 6.VIII.97 - 1 $; Gazzavod, 24.VII.97 - 1 $.

Apatura iris amurensis Stichel, 1909. An Amphipalaearctic species with a range gap between the southern Tyumen Province and Eastern Transbaikalia, firstly found in the Argun' basin. Earlier it was collected by M. ;G. ;Sergeev {1988) at Nerchinsk and by V. ;A. ;Brinikh 10 km N of the village Turga (the Olovyaninskii District). It inhabits valley forests in the southern taiga zone. In the Chita Province it not abundant and deserves protection.

Materials. Unda, 23.VII.97 - 1 $; Gazzavod, 24.VII.97 - 1 $; Argun' valley, 27.VII.97 - 1 # (vo); the brook, 25.VII.97 - 1 #.

Apatura ilia ussuriensis Kurentzov, 1937. An Amphipalaearctic species with a range gap between the Southern Ural and Transbaikalia. Reported by V. ;V. ;Chikolovets (1994) by 5 specimens collected 30 km SW of Karymskaya, in Amazar and Argunsk, besides, collected by V. ;A. ;Brinikh on 21th July 1996 in the National Park "Alkhanai" (Aginskii Buryat Autonomous Region) and by V. ;V. ;Dubatolov on 17-18th July 1997 in the Tsasucheiskii Bor pine forest at the village Nizhnii Tsasuchei (Chita province). This species is very rare in Transbaikalia in general but locally abundant in the Argun' basin.

Materials. Unda, 23.VII.97 - vo; Nerzavod, a brook valley, 6.VIII.97 - 1 $; between the frontier posts Mar'ino and Ust'-Lubiya, 11.VIII.96 - a fore wing; the brook, 25.VII.97 - 3 $, 1 #; 2^nd valley, 31.VII.97 - 8 $; 3^rd valley, 31.VII.97 - 2 $.

*Apatura metis substituta Butler, 1873. An Amphipalaearctic species inhabiting Europe from Hungary to the Southern Ural, then in the southern Irtysh River valley and from Transbaikalia (firstly reported here) to Japan. This species is rare in the Argun' basin, we met it with once in willow thickets in the valley of one of the brooks falling into the Budyumkan River lower reaches. In the steppen zone of the Chita Province it is common: in the Onon River floodland, where collected by us at the village Nizhnii Tsasuchei in 1995-1997, and in the Kyra River floodland, where collected by V. ;K. ;Zintshenko at the village Kyra in 1991 (materials of SZMN expedition of 1991).

Materials. Village Budyumkan, 25.VII.97 - 2 $.

*Neptis thisbe Menetries, 1859. An Amurian-North Chinese species, tat is monophagous on Quercus mongolica. In 1997 we found it in oak woods southwards of the Budyumkan River, where it was extremely rare. This is a first reliable record for Transbaikalia, the species was thought to range in Amurland and Primorye to Korea. All previous reports of this species for the Chita Province (Chikolovets, 1994) referred in fact to a close species Neptis tshetverikovi Kurentz., feeding on the birch (Korshunov, 1996). This species differ well by the costal processus at the valva apex which is wide in N. thisbe (Fig.7) and narrow in N. tschetverikovi (Dubatolov, 1997). N. thisbe should be protected in the Chita Province with the oak woods and all their dwellers altogether. On 30^th July 1997 in an oak forest on the southern slope of the 2^nd valley descending from the mountains at the Argun' River left bank south the Budyumkan River, 10 km S of Uryupino, a pupa of this species was found suspended to an oak leaf underside. It was 22 mm long and has a maximum width, betwen the thornal angles of the wing cases, of 10 mm. It much resembles the pupa of Neptis rivularis in shape, differences being as follows: there are rather large pointed prominences at the second unit of the antennae; the prothorax has a high crest-like saggital projection; either wing case bears a sharp tooth at the base of its dorsal margin; there are also a sharp tooth on either side of the I^st abdominal tergite; the abdominal tergites I-VI bear sharp lateral keels forming rectangular ledges at segment joints. The pupa is evenly golden-glittering.

Materials. Polovinnaya, an oak forest, 29.VII.97 - 1 #; an open mixed larch-Dahurian birch-silver birch forest with participation of the Mongolian oak on a gentle slope of a mountain at the Argun' river right bank between the 1^st andhe 2^nd brook valleys south the Budyumkan River, 8 km S of Uryupino, 30.VII.97 - 1 $.

Neptis tshetverikovi Kurentzov, 1936. A Transbaikalian-Amurian-North Chinese species rarely occuring at almost all the rivers of the Amur Basin in Transbaikalia except for the steppen zone. Deserves protection. It is this species to which the reports of N. thisbe Men. at Amazar, Kuenga and Argunsk (Chikolovets, 1994) should be referred to.

Materials. 25 km NNE of the village Gazimurskii Zavod, the Gazimur River left bankl at the bridge 4 km upstream of the village Kungara, 24.VII.97 - 1 #.

Neptis rivularis magnata Heyne in Ruhl, 1895. A Transpalaearctic species common in open habitats with Spiraea bushes. Reported for Shara, Nerchinskii Zavod and Argunsk (Chikolovets, 1994).

Materials. Nerzavod, a brook valley, 9.VIII.96 - 2 spm; 6.VIII.97 - 1 $; Gazzavod, 24.VII.97 - 2 #; Argunsk, 10.VIII.96 - vo; Zapisina, 10, 13.VIII.96 - 3 spm; Lubiya, 11.VIII.96 - 2 spm; Uryumkan, 11.VIII.96 - vo; Argun' bend, 11.VIII.96 - 1 $; Polovinnaya, 29.VII.97 - 1 #; Polovinnaya valley, 28.VII.97 - 2 #; Budyumkan, 26.VII.97 - 1 $, 1 #; village Budyumkan, 25.VII.97 - 1 #; 3^rd valley, 31.VII.97 - 2 $.

Neptis sappho (Pallas, 1771). A Transpalaearctic species, much less frequent than the previous one, inhabiting forest edges and openings.

Materials. Nerzavod, a brook valley, 9.VIII.96 - 1 spm; Zapisina, 10.VIII.96 -1 spm; Polovinnaya, 28-29.VII.97 - 2 $, 2 #; Argun' valley, 1-2.VIII.97 - 1 #; village Budyumkan, 25.VII.97 - 1 $; the brook, 25.VII.97 - 1 $.

Limenitis populi enapius Fruhstorfer, 1908. A Transpalaearcic species inhabiting forest edges and openings, probably not frequent.

Materials. Budyumkan, 26.VII.97 - 1 $; the brook, 25.VII.97 - 1 $, 2 #.

Limenitis sydyi latefasciata Menetries, 1859. A Palaearchearctic species penetrating into the Altai Mts. The nominotypical subspecies inhabits the Western Altai Mts. and is isolated from the main range in the East. Although it is common in the southern Russian Far East, in Eastern Transbaikalia it is quite local, although sometimes abundant (30 km SW of Karymskaya and in the environs of Amazar V. ;V. ;Chikolovets (1994) collected 16 specimens. M. ;G. ;Sergeev (1988) collected it in the Shilka River valley (opposite to the Nercha River mouth). We found worn-out specimens only to be common on forest roads and at shrubbery on open slopes of river valleys. Suggested for protection in the Chita Province.

Materials. Nerzavod, a forest edge, 6.VIII.97 - 1 spm (vo); Zapisina, 10.VIII.96 - 1 spm; 42 km NE from Serednyaya, 10.VIII.96 - 1 spm; Polovinnaya, 28.VII.97 - 2 $, 2 #; 29.VII - 2 #; Budyumkan, 26.VII.97 - 2 #; 1.VIII.97 - 1 #; the brook, 25.VII.97 - 2 $, 1 #; Gazimur, 31.VII.97 - 1 $, 1 #.

Limenitis helmanni duplicata Staudinger, 1892. A North Tien Shan-West Siberian-Palaearchaearctic species much less frequent in Eastern Transbaikalia than the previous one. The range resembles that of L. sydyi but the western part of the range is greater as extending to Novosibirsk and North Tien Shan. Confined to forest edges openings and river valleys.

Materials. Polovinnaya, 29.VII.97 - 1 # (vo); Budyumkan, 26.VII.97 - 1 $; the brook, 25.VII.97 - 1 #; 2^nd valley, 31.VII.97 - 1 $.

Polygonia c-album kultukensis Kleinschmidt, 1929. A Transpalaearctic species rather common in forests and riparian thickets.

Materials. Nerzavod, a brook valley, 9.VIII.96 - 1 spm; Zapisina, 10.VIII.96 - 1 spm; Polovinnaya, 29.VII.97 - 1 $.

Nymphalis vaualbum (Denis et Schiffermьller, 1775). A Transpalaearctic species very abundant in forests and floodland thickets. Reported for Shara (Chikolovets, 1994).

Materials. Ulan, 8.VIII.96 - 3 $, 1 #; Ildikan, 9.VIII.96 - 1 spm; 15 km S of the village Kalga, 8.VIII.96 - 1 #; Nerzavod, a brook valley, 9, 14.VIII.96 1 #, vo - in abundance, 6.VIII.97; Zapisina, 10.VIII.96 - vo; Vereya, 10.VIII.96 - vo; Lubiya, 11.VIII.96 - vo; Uryumkan, 11.VIII.96 - vo; Argun' bend, 11.VIII.96 - vo; Argun' bank, 12.VIII.96 - vo; Budyumkan, 11.VIII.96 - vo; 26.VII.97 - 1 $; the brook, 25.VII.97 - 2 $.

Nymphalis xanthomelas (Esper, 1780). A Transpalaearctic species inhabiting the same places as the two previous species but less abundant than Nymphalis vaualbum.

Materials. Ulan, 8.VIII.96 - 1 $; Ildikan, 9.VIII.96 - 1 $; Nerzavod, a brook valley, 6.VIII.97 - vo; the mine, 4.VIII.97 - 1 $; Polovinnaya, 29.VII.97 - 1 $; village Budyumkan, 25.VII.97 - 1 $; 2^nd valley, 31.VII.97 - 1 $.

Nymphalis antiopa (Linnaeus, 1758). A Transpalaearctic species inhabiting forests with participation of the birch, rather common.

Materials. Ulan, 8.VIII.96 - vo; Ildikan, 9.VIII.96 - 1 $; Nerzavod, a brook valley, 9, 14.VIII.96 - 4 spm; Zapisina, 10.VIII.96 - vo; Vereya, 10.VIII.96 - vo; Lubiya, 11.VIII.96 - vo; Uryumkan, 11.VIII.96 - vo; Argun' bend, 11.VIII.96 - vo; Argun' bank, 12.VIII.96 - vo; Budyumkan, 11.VIII.96 - vo.

Inachis io (Linnaeus, 1758). A Transpalaearctic species rarely occuring on opem places, usually ruderal, with neetle thickets.

Materials. The mine, 4.VIII.97 - 1 $; Budyumkan, 11.VIII.96 - 1 spm.

Araschnia levana (L.innaeus, 1758). A Transpalaearctic species, probably rare. Pertained to damp meadows, clearings and open stands in forests and in floodlands where the neetle grows being the foodplant.

Materials. Ildikan, 8.VIII.96 - 1 spm.

*Araschnia burejanaЃ.”ћ Bremer, 1861. A Palaearchearctic species firstly being reported for Siberia. Earlier it was recorded in Russia only in Amurland and Primorye. We collected two caterpillars beneath willow thickets at a brook an a gentle slope of a mountain on the Argun' left bank. One of them were preserved in alcohol, the other have pupated. Species identification on both preimaginal phases (Fukuda et al, 1983) was doubtless, it was proved by Prof. ;T. ;Fujioka.

Melitaea sutschana transbaicalia Bryk, 1940. pict. 2 pict. 3. A Transbaikalian-Amurian species. Common and locally very abundant on steppefied meadows on open slopes, less abundant on mesophytous meadows. Noteworthy that no specimen of this species was observed at Nerchinskii Zavod in spite of abundance of suitable habitats. Maybe it finish flying there earlier than at more northerly situated Uryupino.

V. V. Chikolovets (1994) has reported for Shara, Argunsk, Karymckoe, Amazar and Kuenga a steppen species Melitaea didymoides Ev. Most probably, these records in fact whould be referred to M. sutchana, inhabiting more northerly areas..

Materials. Unda, 23.VII.97 - 1 $, 2 #; Gazzavod, 24.VII.97 - 1 #; Polovinnaya, 28-29.VII.97 - 4 $, 1 #; Budyumkan, 11.VIII.96 - 1 $, 1 #; 26.VII; 1-2.VIII.97 - 4 S, 10 #; the brook, 25.VII.97 - 1 $; Gazimur, a steppefied slope, 31.VII.97 - 1 $.

Melitaea diamina hebe (Borkhausen, 1793). A Transpalearctic species, occuring mainly in forest fields and wet meadows.

Materials. Unda, 23.VII.97 - 1 #.

Melitaea baicalensis (Bremer, 1861) (= arcesia Bremer, 1861). An East-Palaearctic species. Reported for Argunsk (27^th July 1993) (Chikolovets, 1994); not found by us.

Melitaea phoebe saturata Staudinger, 1892. A Transpalaearctic species of dry and steppefied medows common in Transbaikalia but almost escaping from us due to an earlier flight period.

Materials. Alekzavod, 22.VII.97 - 1 #; Nerzavod, 6.VIII.97 -vo.

Clossiana selene (Denis et Schiffermьller, 1775). A Transpalaearctic species of wet meadows.

Materials. Unda, 23.VII.97 - 2 $, 1 #.

Clossiana selenis Ev. An East-Palaearctic species commmon on damp meadows, forest openings and roads.

Materials. Ildikan, 9.VIII.96 - 2 #; Nerzavod, 9.VIII.96 - 2 #; 6.VIII.97 - 1 #; Argunsk, 13.VIII.96 - 1 #; Zapisina, 13.VIII.96 - 2 $; the mine, 4.VIII.97 - 1 $; Argun' bend, 11.VIII.96 - 2 $; Polovinnaya valley, 28.VII.97 - 1 $; Argun' valley, 12.VIII.96 - vo; 28-29.VII.97 - 3 #.

Clossiana angarensis (Erschoff, 1870) pict. 2 . An East-Palaearctic species flying together with the previous species but somewat less abundantly.

Materials. Zapisina, 10, 13.VIII.96 - 5 #; Vereya mts., 10.VIII.96 - 3 #; the mine, 4.VIII.97 - 1 #; Lubiya, 10.VIII.96 - 3 #; Uryumkan, 11.VIII.96 - 2 #; Argun' bend, 11.VIII.96 - 2 #; Polovinnaya, 29.VII.97 - 1 $; Polovinnaya valley, 28.VII.97 - 1 #; village Budyumkan, 25.VII.97 - 1 $; the brook, 25.VII.97 - 1 $, 3 #; 2^nd valley, 31.VII.97 - 3 $.

Brenthis ino paidicus (Fruhstorfer, 1907) A Transpalaearctic species common on damp and mesophytous meadows. Reported for Nerchinskii Zavod (Chikolovets, 1994).

Materials. Akatui, 23.VIII.97 - 2 $; Unda, 23.VII.97 - 2 $, 2 #; Nerzavod, a brook valley, 9.VIII.96 - 3 #; 6.VIII.97 - 1 #; Solontsy, 5.VIII.97 - 1 $, 1 #; Gazzavod, 24.VII.97 - 1 $, 1 #; Kurleya, 5.VIII.97 - 1 $; Argun' bend, 11.VIII.96 - 1 #; ; Polovinnaya, 29.VII.97 - 2 #; 28.VII.97 - 1 $, 2 #; Argun' valley, 30.VII.97 - 1 $; Budyumkan mouth, 26.VII, 1.VIII.97 - 2 #; the brook, 25.VII.97 - 1 $, 2 #; 2^nd valley, 31.VII.97 - 1 $.

Brenthis daphne ochroleuca (Fruhstorfer, 1907). An Transpalaearctic species with a disjunctive range with gaps between the Southern Ural and Altai, the Altai and Baikal region. Inhabits dry and mesophylous meadows, forest openings, not abundant.

Materials. Ulan, 8.VIII.96 - 1 #; Ildikan, 9.VIII.96 - 1 #; Nerzavod, a brook valley, 9.VIII.96 - 3 #; Gazzavod, 24.VII.97 - 1 $; Argunsk, 13.VIII.96 - 1 #; Budyumkan, 1.VIII.97 - 1 #; the brook, 25.VII.97 - 1 #.

Fabriciana adippe zarewna (Fruhstorfer, 1912). A Transpalaearctic species common on various meadows, from steppefied to mezophytic. Reported for Argunsk (Chikolovets, 1994).

Materials. Nerzavod, a brook valley, 9.VIII.96 - 3 $, 3 #; 6.VIII.97 - 3 $; Argunsk, 13.VIII.96 - 1 $; the mine, 4.VIII.97 - 1 $; Argun' bend, 11.VIII.96 - 1 $; Polovinnaya, 29.VII.97 - 2 $, 28.VII.97 - 2 $; Argun' valley, 1-2.VIII.97 - 1 #; Budyumkan mouth, 26.VII, 1-2.VIII.97 - 3 $, 1 #.

Fabriciana niobe changaica (Reuss, 1922). A Transpalaearctic species common on various meadows, in general preferring more dry habitats than the previous one.

Materials. Ulan, 8.VIII.96 - 1 $, 1 #; Ildikan, 9.VIII.96 - 1 #; Nerzavod, a brook valley, 9.VIII.96 - 1 $; 6.VIII.97 - 1 $; Gazzavod, 24.VII.97 - 1 #; Argunsk, 13.VIII.96 - 1 $; Argun' bend, 11.VIII.96 - 1 $; Budyumkan, 26.VII.97 - 1 $; the brook, 25.VII.97 - 1 $.

Mesoacidalia aglaja kenteana (Stichel, 1908). A Transpalaearctic species, together with Fabriciana adippe common on various meadows from steppefied to mesophytic.

Materials. Unda, 23.VII.97 - 2 $, 1 #; Nerzavod, a brook valley, 9.VIII.96 - 2 #; 6.VIII.97 - 1 #; Gazzavod, 24.VII.97 - 2 $; Argun' bend, 11.VIII.96 - 1 $; Argun' valley, 30.VII.97 - 1 #; Budyumkan, 11.VIII.96 - 1 #; 26.VII, 1.VIII.97 - 3 $, 3 #; 3^rd valley, 31.VII.97 - 1 $.

Damora sagana paulina Nordmann, 1851. pict. 2 A South-Siberian-Palaearchearctic forest species with a disjunctive range: Altai Mts. and the Kuznetskoe Upland (in a broad sense, including Salairskii Kryazh) and then, after a gap, from Irkutsk to the Pacific. In 1996 at Nerchinskii Zavod it was the most abundant and mass butterfly species on forest and valley meadows, in 1997 its quantity reduced much there but in open forests and glades south of Uryupino it was still the most numerous butterfly, together with Erebia neriene Bцb.

Materials. Nerzavod, a brook valley, 9, 14.VIII.96 - 6 $, 9 # (vo - in mass quantities); 6.VIII.97 - 4 #; Gazzavod, 24.VII.97 - 3 $; Zapisina, 10.VIII.96 - vo; Vereya mts., 10.VIII.96 - 1 #; Lubiya, 11.VIII.96 - 2 #; Argun' bend, 11.VIII.96 - 1 #; Polovinnaya, 28.VII.97 - 7 $, 8 #; 29.VII.97 - 2 $, 2 #; Argun' valley, 12.VIII.96 - vo, 27.VII.97 - 1 $, 1 #; 30.VII.97 - 2 $, 5 #; 1-2.VIII.97 - 1 $; Budyumkan, 11.VIII.96 - 1 #; 26.VII.97 - 3 $; 1.VIII.97 - 1 $, 3 #; Budyumkan mouth, 1.VIII.97 - 2 #; the brook, 25.VII.97 - 1 $, 1 #; 2^nd valley, 30.VII.97 - 2 #.

Argynnis paphia neopaphia Fruhstorfer, 1907. A Transpalaearctic species common on glades and in open forests but less numerous than the previous one. Reported for Shara and Argunsk (Chikolovets, 1994).

Materials. Nerzavod, a brook valley, 9.VIII.96 - 2 $, 1 #; 6.VIII.97 - 1 $, 1 #; Gazzavod, 24.VII.97 - 1 $; Zapisina, 10, 13.VIII.96 - vo; Vereya, 10.VIII.96 - 1 $; Vereya mts., 10.VIII.96 - 1 $, 1 #; Lubiya, 11.VIII.96 - vo; Argun' bend, 11.VIII.96 - 1 #; Polovinnaya, 28-29.VII.97 - 2 $, 2 #; Argun' bank, 12.VIII.96 - vo; Budyumkan, 11.VIII.96 - vo; 26.VII, 1.VIII.97 - 2 #; 2^nd valley, 31.VII.97 - 1 #.

Kirinia epimenides (Menetries, 1859). A Transbaikalian-Amurian-Manchurian forest species common in Primorye and rare in Eastern Transbaikalia. Earlier was reported for Transbaikalia only from the Shilka River basin. 15th July 1997 a single male was collected in the Onon River right bank floodland in an open Ulmus pumila grove 3 km upstream of the village Nizhnii Tsasuchei, i.e. within the steppen zone. In the Argun' basin the species was found in mixed forests with participation of the Mongolian oak south of the Budyumkan River and at willow patches in the Gazimur lower flow floodland at the village Kurleya. The butterflies were scarce, only once we met three specimens altogether on a local woody (larch/birch/oak) hilltop just north of the Polovinnaya Pad' valley, which occupied brightly illuminated spots on larch trunks and actively tried to chase out each other. The species is suggested for protection for the Chita Province.

Materials. Kurleya, 24.VII.97 - 1 #; 5.VIII.97 - 2 #; Polovinnaya, 28.VII.97 - 1 $; Argun' valley, 12.VIII.96 - 1 #; Budymkan, 26.VII.97 - vo; the brook, 25.VII.97 - vo.

Lopinga achine (Scopoli, 1763). A Transpalaearctic species. Much worn out specimens steadily occured in the Uryupino environs in 1997 on mixed forest openings and edges.

Materials. Polovinnaya (slopes and valley), 28-29.VII.97 - 3 #; Argun' valley, 27, 30.VII.97 - 2 #; the brook, 25.VII.97 - 1 #.

Crebeta deidamia (Eversmann, 1851). An East-Palaearctic species rather common on edges and openings in montane mixed forests.

Materials. Ildikan, 9.VIII.96 - 1 #; Akatui, 23.VIII.97 - 1 $; Zapisina, 10.VIII.96 - 1 #; Vereya mts., 10.VIII.96 - 1 #; Argun' bend, 11.VIII.96 - 2 $, 1 #; Polovinnaya, 28.VII.97 - 1 $, 1 #; Budyumkan, 26.VII.97 - 1 $; 2^nd valley, 30.VII.97 - 1 $; Gazimur, 31.VII.97 - 1 $.

Coenonympha amaryllis (Stoll, 1782). A South Siberian-Amurian species comfined to steppen habitats. It is very abundant in the southern steppen parts of the region considered, in the forest zone it inhabits dry and steppefied meadows mostly on southern slopes. It is expected that in early summer this species is more abundant. Reported for Nerchinskii Zavod (Chikolovets, 1994).

Materials. Ulan, 8.VIII.96 - 3 $, 1 #; 15 km S of the village Kalga, 8.VIII.96 - 1 $, 1 #; Alekzavod, 22.VII.97 - 1 $; Nerzavod, a brook valley, 6.VIII.97 - 1 $; Gazzavod, 24.VII.97 - 1 $; Polovinnaya, valley, 28.VII.97 - 2 #; Budyumkan mouth, 26.VII, 1.VIII.97 - 2 #.

Coenonympha glycerion iphiclis Staudinger, 1892. A South Siberian steppen subspecies of a Transpalaearctic species. In Argun' and Onon basins it is common in steppen parts on dry and steppefied meadows. This subspecies is characterized with small ocelli on the hind wing underside (Dubatolov, 1997).

Materials. Ildikan, 9.VIII.96 - 2 #; Akatui, 23.VII.97 - 1 #; Alekzavod, 22.VII.97 - 1 #; Unda, 23.VII.97 - 2 $, 3 #; Solontsy, 5.VIII.97 - 1 $, 3 #; Gazzavod, 24.VII. 97 - 1 $, 1 #; Kurleya, 5.VIII.97 - 1 #; Polovinnaya, 29.VII.97 - 1 #; village Budyumkan, 25.VII.97 - 1 $; 2^nd valley, 31.VII.97 - 1 $.

Coenonympha glycerion heroides Christoph, 1893. An East-Siberian subspecies of the same Transpalaearctic species pertained to open mesophytous habitats of the forest zone. It ranges from Eastern Transbaikalia to Central Yakutia and Amur Region and is characterized by larger ocelli, with wide brick-red rims, on the hind wing underside that sometimes makes it resembling C. hero L. (Dubatolov, 1997). In Eastern Transbaikalia these subspecies contact each other, so in some localities the specimens seem to be transitory.

Materials. Nerzavod, a brook valley, 9.VIII.96 - 1 #; 6.VIII.97 - 1 #; Argun' bend, 11.VIII.96 - 2 #; Budyumkan, 11.VIII.96 - vo; 1.VIII.97 - 2 #.

Erebia neriene (Boeber, 1809) pict. 2. South Siberian-Amurian species which is very abundant and usually dominating to be the most plentiful butterfly in mixed forests, on glades, openings and edges.

Materials. Akatui, 23.VIII.97 - 4 $; Unda, 23.VII.97 - 2 $, 1 #; Nerzavod, a brook valley, 6.VIII.97 - 1 #; Zapisina, 13.VIII.96 - 1 #; Vereya mts., 10.VIII.96 - vo; Kurleya, 5.VIII.97 - 1 #; Lubiya, 11.VIII.96 - 3 $, 4 #; Uryumkan, 11.VIII.96 - 1 #; Argun' bend, 11.VIII.96 - 3 $, 6 #; Polovinnaya, 28-29.VII.97 - 2 $; Argun' valley, 27.VII.97 - 2 #; Argun' bank, 12.VIII.96 - 2 $; Budyumkan, 1.VIII.96 - 1 $; 26.VII, 1.VIII.97 - 7 $, 2 #; the brook, 25.VII.97 - 2 $; 2^nd valley, 31.VII.97 - 2 $; Gazimur, 31.VII.97 - 1 $.

For Shara and Argunsk V. V. Chikolovets (1994) has reported another species of Erebia - E. dabanensis Ersch., 8 specimens of which were collected on 22^nd and 26^th July 1993. By our observations, in Transbaikalia this species occurs high in the mountains at the tree-line and above, flying from late June maximum till 20^th July. It is hard to suppose to which species these records should be in fact referrred to.

Aphantopus hyperantus sibiricus Obrastzov, 1936. A Transpalaearctic species flying on meadows, forest edges and openings. We collected the last, very worn out females, the species should be much more abundant in early summer.

Materials. Akatui, 23.VIII.97 - 1 #; Unda, 23.VII.97 - 1 #; Budyumkan mouth, Polovinnaya, 28.VII.97 - 1 #; 26.VII, 1.VIII.97 - 3 #.

Hyponephele lycaon pasimelas (Staudinger, 1886). A Transpalaearctic species preferring dry and steppefied meadows. Eastern Transbaikalia is a zone of transition between a Mongolian subspecies H. ;l. ;catalampra (Staudinger, 1895) and the subspecies H. ;l. ;pasimelas (Staudinger, 1886), common in Amurland and Primorye, which differ drastically in wing colouration. In H. ;l. ;catalampra the fulvous area on the fore wing underside is well developwed in males, the fulvous band with ocelli on the fore wing is contiguous in females. In H. ;l. ;pasimelas the fulvous area on the fore wing underside is practically absent in males, in females the fulvous band on the fore wing upperside is split, as in H. ;lupina Costa. In spite of these differences, in serial materials from practically all sites of Eastern Transbaikalia transitory specimens can be found. However, in the Argun' basin the majirity of specimens correspond to H. ;l. ;pasimelas Stgr.

Materials. Ulan, 8.VIII.96 - 6 $, 2 #; Ildikan, 9.VIII.96 - 11 spm; 15 km S of the village Kalga, 9.VIII.96 - 2 #; Alekzavod, 22.VII.97 - 3 $, 4 #; Unda, 23.VII.97 - 1 #; Nerzavod, a brook valley, 9.VIII.96 - 1 $, 1 #; 6.VIII.97 - 5 $, Gazzavod, 24.VII.97 - 1 $; Kurleya, 5.VIII.97 - 1 #; Budyumkan mouth, 26.VII, 1-2.VIII.97 - 7 #.

Satyrus ferula liupiuschani O. Bang-Haas, 1933. The species ranges from Southern Europe to Amurland and Central Asia, in the region studied is confined to steppefied meadows on open southern slopes. Reported for Shara and Argunsk (Chikolovets, 1994).

Materials. Nerzavod, 6.VIII.97 - 1 #; Polovinnaya valley, 28.VII.97 - 1 $, 1 #; Polovinnaya, 29.VII.97 - 2 #; Budyumkan mouth, 1.VIII.97 - 1 #; Gazimur, 31.VII.97 - 1 #.

Satyrus dryas septentrionalis (Wnukowsky, 1929). A Transpalaearctic species quite common on open meadowy habitats, mostly dry and steppefied meadows. Reported for Shara, Nerchinskii Zavod and Argunsk (Chikolovets, 1994).

Materials. Ulan, 8.VIII.96 - vo; Ildikan, 9.VIII.96 - 2 spm; Unda, 23.VII.97 - 5 $, 1 #; Nerzavod, 9, 14.VIII.96 - vo; Solontsy, 5.VIII.97 - 1 $; Argunsk, 13.VIII.96 - 3 #; Kurleya, 5.VIII.97 - 1 #; Argun' bend, 11.VIII.96 - 1 $; Polovinnaya, 29.VII.97 - 1 $; Budyumkan, 11.VIII.96 - 1 $; 1.VIII.97 - 1 $; 2^nd valley, 31.VII.97 - 1 #; Gazimur, 31.VII.97 - 1 $.

Hipparchia autonoe sibirica (Staudinger, 1861). The species ranges from South-Eastern Europe to Transbaikalia and Korea and keeps to open dry and steppefied meadows on rocky southern slopes and open hilltops.

Materials. Ulan, 8.VIII.96 - 1 #; Nerzavod, 6.VIII.97 - 1 $; Polovinnaya, 28-29.VII.97 - 2 #; Budyumkan, 11.VIII.96 - 1 $; 26.VII, 1.VIII.97 - 3 $, 2 #; Gazimur, 31.VII.97 - 1 $.

Melanargia halimede (Menetries, 1858). A Transbaikalian-Amurian species abundant in Amurland and Primorye but rare in Transbaikalia where is present only in most south-eastern regions. Mostly keeps to open forest-steppen habitats, very rarely found either in steppes or forest openings. The species suggested for protection in the Chita Province. It is this species to which the report by V. V. Chikolovets (1994) for Nerchinskii Zavod should be referred to. In fact M. epimede does not occur westwards of the Zeya River.

Materials. Ulan, 8.VIII.96 - 1 #; Ildikan, 9.VIII.96 - 1 #; 25 km ENE from Kalga village, between Srednyaya Borzya river and Chashino-Il'dikan village, 7.VIII.97 - 1 #; the village Kalga, 7.VIII.97 - 2 #; Argun' bend, 11.VIII.96 - 1 #; Nerzavod, 6.VIII.97 - 2 $, 8 #; Solontsy, 5.VIII.97 - 1 #.

Thus, we collected 87 butterfly species. With species added which were reported by V. V. Chikolovets (1994) this number rises to 92. The complete list should be much longer thanks to earlier flying species. The most part of them, 51 ones, are Transpalaearctic, Holarctic, or cosmopolitian, 21 species have East Palaearctic ranges (mostly embracing Siberia and the Far East, they are Pyrgus speyeri, Hesperia florinda, Parnassius nomion, Leptidea amurensis, Colias heos, Nordmannia prunoides, Tongeia fischeri, Glaucopsyche lycormas, Maculinea kurentzovi, Lycaeides subsolanus, Polyommatus erotides, Limenitis sydyi, L. ;helmanni, Melitaea. ;plotina, M. baicalensis, Clossiana selenis, C. ;angarensis, Damora sagana, Crebeta deidamia, Coenonympha amaryllis, Erebia neriene), 15 species are East Asian, both strictly Palaearchearctic and those widely penetrating into Eastern Transbaikalia (Pyrgus schansiensis, Sinoprinceps xuthus, Pieris melete, P. ;dulcinea, Neozephyrus japonicus, Favonius taxila, F. ;cognatus, Niphanda fusca, Celastrina ladonides, Neptis thisbe, N. ;tschetverikovi, Araschnia burejana, Melitaea sutschana, Kirinia epimenidis, Melanargia halimede), 2 species may be called European-Siberian (Colias hyale, C. ;chrysotheme), 2 species are Amphipalaearctic (Apatura iris, A. ;ilia), a similar type pf range has A. ;metis (there is an isolate of this species in West Siberia). It should be concluded that the fauna considered has quite an easternl composition and is transitory between Siberian and Manshurian faunas. Eight East Asian species (Pyrgus (alveus) sсhansiensis, Pieris (napi) melete, Favonius taxila, F. cognatus, Celastrina ladonides, Apaura metis, Neptis thisbe, Araschnia burejana) are for the first time being reported for Chita Region and Siberia.

However, an acquaintance with the butterfly fauna of the Lower Argun' basin in Nature leaves a subjective impression as being Siberian, owing to the fact that all its East Asian species, except for Sinoprinceps xuthus, Apatura ilia and Melitaea suchana, are met with as scarce specimens (even species of the Pieris napi group, which can't be called stenotopic), while an overwhelming majority of butterflies is represented by common Siberian species. Noteworthy that three of species new for Transbaikalia, namely Favonius taxila, F. ;cognatus, Neptis thisbe, are monophagous on the Mongolian oak and are very scarce and strictly confined to these trees. On the contrary, vegetation and flora of the Argun' valley and its close vicinity is impressive as rich in Manchurian elements in both quantitative and qualitative aspects.