Stenus proprius is recorded from Greece (Schülke and Smetana 2015: 837), northeastern Iran (Puthz 2003: 93), and Central Asia (Kastcheev and Puthz 2011: 450). A second Iranian locality was recently discovered in the northwestern Zagros Mountains (Kordestan). Judging from the findings in the very northwest and northeast of Iran (Fig. 2), S. proprius is most probably distributed across the north of the country.

Although the species was found in Greece and is expected to occur in Anatolia, its main distribution in Central Asia concurs with the Turkestanian glacial refuge. Thus, Stenus proprius can be regarded as an expansive Turkestanian faunal element. Kastcheev and Puthz (2011: 454) described this species as Kazakhstan-Turanian. Hitherto, S. proprius is the only representative of the S. alpicola species group in Iran.

Stenus affaber is previously published for Lebanon, Syria, Turkey, Iran, and Kazakhstan. It is collected in the eastern Zagros Mountains, northern Fars (Fig. 3). The record from Kazakhstan is, however, dubious, because it is based on a female only identified as S. cf. affaber (Kastcheev and Puthz 2011: 439). The lack of records between Southwest Iran and Kazakhstan moreover does not support a Central Asian distribution.

Kastcheev and Puthz (2011: 454) consider Stenus affaber to be a species of Mediterranean origin. Judging from the distribution west (Levant), north (Anatolia), and east (Zagros Mountains) of the Mesopotamian plain, however, we assign this rarely collected species to the Syrian faunal element.

Stenus ater is widespread in the West Palaearctic and recorded as far east as European Russia, Azerbaijan, and North Iran, where it reaches its eastern limit of distribution in the Turkmeno-Khorasanian Mountains at about 58°06’E (Fig. 3). Records from Kazakhstan (Smetana 2004: 554), which were adopted by Schülke and Smetana (2015: 806), mainly refer to other species and are not reliable (Kastcheev and Puthz 2011: 454). In Iran, S. ater is the most widespread member of the S. ater group. Towards the east, it is replaced by its close relative S. mongolicus. The two species occur sympatrically in the eastern Elburz and the Turkmeno-Khorasanian Mountains (Fig. 3). Ghahari et al. (2009b: 1964) recently published S. ater for Behshahr, Mazandaran, a record which is in accord with the distribution pattern of the species.

Judging from the vast distribution in the Mediterranean, we consider Stenus ater to be an expansive Holomediterranean faunal element.

Stenus hypoproditor is distributed from the northeastern Mediterranean, Southeast Europe, Turkey, and Iran as far east as Kazakhstan, Uzbekistan, and Kyrgyzstan. In Iran, it is known from the northwest (Fig. 3) only. The find in the northwestern Zagros Mountains at about 36°59’N constitutes the southernmost record of this species. Further to the south, S. hypoproditor is replaced by the allopatric relative S. nodipes.

Kastcheev and Puthz (2011: 454) consider Stenus hypoproditor to be a Mediterranean species. According to the Pleistocene refuge theory, it can be regarded as an expansive Pontomediterranean faunal element.

Stenus intricatus zoufali is distributed from southeastern Central Europe and the Balkans across Anatolia, Transcaucasia, and Iran as far east as Central Asia and Afghanistan (Kastcheev and Puthz 2011: 445). In Iran, the species is distributed in the north, but the record in the southeast at about 30°17’N (Kerman), the southernmost collecting site of the S. ater group, suggests the distribution in most of the country (Fig. 3).

Kastcheev and Puthz (2011: 454) describe Stenus intricatus zoufali as a Mediterranean species. Judging from the distribution in the southeastern Mediterranean, we consider it to be an expansive Pontomediterranean faunal element.

Stenus mongolicus is widely distributed in Asia and the Middle East from China, Mongolia, and East Siberia as far south as Indian Kashmir, Pakistan, Afghanistan, and Iran and westwards to Anatolia and Caucasia. In Iran, the species is restricted to the Elburz and Turkmeno-Khorasanian Mountains in the northeast and recorded as far south as 35°42’N in Razavi Khorasan (Fig. 3). Recent records from the lowlands of Ivanaky, Semnan Province (Hadian et al. 2011: 4), and from rice fields and grassland in Lahijan, Gilan (Ghahari et al. 2009c: 661) need confirmation.

Kastcheev and Puthz (2011: 454) consider Stenus mongolicus as a Kazakhstan-Turanian species. Judging from its Central Asian distribution centre, S. mongolicus can be regarded as a Turkestanian faunal element, which expanded westward.

Described from Bulgaria (Puthz 1972b: 250), Stenus nodipes is common from the Balkans throughout Turkey and Syria eastwards to Armenia and Iran (Puthz 2009: 34). In Iran, the species is known only from a comparatively small area in the northwestern Zagros Mountains between southern West Azarbaijan and northern Ilam (Fig. 3).

Due to its distribution in Southeast Europe, Anatolia, and the Caucasus region, we consider Stenus nodipes to be an expansive Pontomediterranean species.

Stenus skoraszewskyi was described from Kars, northeastern Turkey (Korge 1971: 21), and also recorded for Armenia and Iran, where it was found in the very northwest of West Azarbaijan and in the Central Elburz near Tehran, the southeasternmost record of the rare species at about 36°N 51°E (Fig. 3).

These few, scattered localities in the Irano-Anatolian highlands and the Elburz do not sufficiently describe the distribution pattern of Stenus skoraszewskyi, which is why we preliminarily term it as an Irano-Anatolian species.

The nominotypical subspecies of Stenus brunnipes is widely distributed in the West Palaearctic eastwards to Iran and Turkmenistan. In Iran, the subspecies seems to be restricted to the northern mountain ranges, where it was found in the eastern Elburz and the Turkmeno-Khorasanian mountains (Fig. 4).

Puthz (2012a: 288) considers Stenus b. brunnipes to be Holomediterranean and we follow this hypothesis.

The Holarctic Stenus canaliculatus is widely distributed across the temperate and northern Palaearctic as far east as Russian Far East and China. In Iran, the species is confined to the temperate north (West Azarbaijan, Ardabil, Mazandaran; Fig. 5). Thus, the record from Fars (Samin et al. 2011a: 2, 2011c: 1238), far south of the confirmed distribution, is implausible.

Stenus canaliculatus, a faunal element of the temperate Holarctic, cannot be assigned to any of de Lattin’s (1951, 1957, 1967) southern Palaearctic glacial refuges.

Stenus cautus is widely distributed across the temperate and northern Palaearctic from France to the Russian Far East. The first record for Iran was published by Puthz (2012a: 304). As far as known presently, the species reaches its southern limit of distribution in the northwest of Iran (Fig. 6), where it was found as far south as Chadegan (Esfahan Province).

No biogeographical assigning is possible for this trans-Palaearctic species.

The distribution of the polytypical Stenus planifrons reaches from Germany and Switzerland over the Balkans, Anatolia, the Levant, and the Ukraine eastwards to South Russia, Caucasia, Iran, and Turkmenistan. In Iran, the species is represented by the southeastern subspecies S. p. robustus, which is distributed in Cyprus, Lebanon, Israel, Syria, Anatolia, Iraq, and northern Iran as far east as Turkmenistan.

Due to this arched areal north, west, and east of the Mesopotamian plain, the evolutionary origin of the subspecies goes back to the Syrian Pleistocene refuge. In Iran, Stenus p. robustus reaches its southern and eastern distribution limit in the southern Zagros Mountains (29°40’N) and the Turkmeno-Khorasanian mountain ranges (59°54’E) (Fig. 7).

This cold resistant taxon was found in altitudes up to 3250 m.

Described from the Talish Mountains (Puthz 1972d: 127), Stenus caspius has its main distribution in Transcaucasia and the South Caspian mountain ranges from Georgia as far east as the Turkmeno-Khorasanian mountains. It apparently is the most common Stenus in the Hyrcanian zone in the northern slopes of the Talish and Elburz Mountains, but it was also found outside of this biogeographical unit in West Azarbaijan, the northern Zagros Mountains, and south of the Elburz (Fig. 8).

Judging from this distribution pattern, Stenus caspius is a typical expansive Caspian faunal element.

The nominotypical subspecies of Stenus providus is widespread in the West Palaearctic as far east as Kazakhstan (Kastcheev and Puthz 2011: 450). The first record for Iran in this work is missing in the current Catalogue of Palaearctic Coleoptera (Schülke and Smetana 2015: 837). In Iran, S. p. providus is distributed in the South Caspian mountains and the very north of the Zagros Mountains (Fig. 8). In the Hyrcanian zone, the species is replaced by its close, allopatric relative S. caspius, but in high elevations of the northern slopes of the Elburz Mountains there is a narrow zone of sympatry.

Judging from the distribution in all of the arboreal Mediterranean, Stenus providus is to be attributed to the Holomediterranean distribution type. Kastcheev and Puthz (2011: 454) already described it as a Mediterranean species.

Stenus aereus is distributed in Caucasia, the Middle East, Central Asia, and West Siberia. In Iran, it apparently is a rare species, which we did not succeed to collect. The record from West Azarbaijan published by Samin et al. (2011b: 140) is plausible in view of the record from East Azarbaijan (Fig. 9), but needs confirmation.

Kastcheev and Puthz (2011: 454) term Stenus aereus a Kazakhstan-Turanian species. According to the hypothesis of Pleistocene refuges, we consider it to be an expansive Turkestanian faunal element, which dispersed towards the Mediterranean.

The Middle Eastern Stenus asiaticus is recorded for Georgia, Turkey, Syria, Iraq, Iran, and Turkmenistan. In Iran, it is the most widespread member of the S. comma species group and distributed in the South Caspian mountains and the northern Zagros Mountains (Fig. 9).

It is difficult, to assign Stenus asiaticus to a particular distribution type judging from the total distribution. In view of the high abundance of records in the Hyrcanian zone in the northern slopes of the Elburz Mountains and the distribution in Transcaucasia, the regions which constitute the Caspian refuge, we consider S. asiaticus to be an expansive Caspian faunal element.

Described from Macedonia and Turkey (Puthz 1972c: 170), Stenus bicornis is distributed in the Balkans and Anatolia. The recent records in the very northwest of Iran (Fig. 9) are the first for the Iranian fauna and represent the easternmost known localities of this species.

Due to its distribution in the northeastern Mediterranean, Stenus bicornis can be regarded as a Pontomediterranean species.

Stenus biguttatus is widely distributed across the northern Palaearctic eastwards to Russian Far East and Japan (Kastcheev and Puthz 2011: 440). In Iran, the species seems to be rare and restricted to the northwest, where we collected it just once (Fig. 9). The dubious records from Rasht and Fouman published by Samin et al. (2011a: 2, 2011c: 1238) were not adopted by Schülke and Smetana (2015: 808).

The enormous area of distribution of Stenus biguttatus cannot be attributed to a particular Pleistocene refuge and distribution type, respectively.

The Holarctic Stenus comma is widespread across the temperate and northern Palaearctic as far east as Russian Far East, China, and Japan. In Iran, the northern species seems to be confined to the temperate northwest. Our find in West Azarbaijan constitutes the first country record of S. c. comma for Iran (Fig. 9).

The wide distribution of this species cannot be explained by the Pleistocene refuge theory.

Stenus araxis was described from Armenia (Ryvkin 1990: 213) and already recorded for Iran (Schülke and Smetana 2015: 805), where it is distributed from the northwest throughout the Iranian highlands as far east as 53°13’E in North Khorasan and as far south as 29°06’N in Central Fars (Fig. 10). Particularly in the Zagros Mountain, we usually collected S. araxis in high abundance.

The distribution pattern of Stenus araxis definitely matches the Iranian glacial refuge.

Stenus turk is recorded from Azerbaijan, Georgia, Ukraine, Turkey, Iran, and Central Asia. Both Iranian representatives of the S. cordatus species group, S. araxis and S. turk, reach their southern distributional limit in Iran and occur sympatrically in the Zagros and Elburz Mountains (Fig. 10). Recent Iranian records of S. turk were mostly collected in the Khorasan provinces in the northeast, which concurs with the wide distribution of this species in Central Asia.

Kastcheev and Puthz (2011: 454) described Stenus turk as Kazakhstan-Turanian species. Judging from its distribution pattern in Central Asia, this species represents the Turkestanian faunal element.

Stenus crassus is widely distributed across the temperate and northern West Palaearctic eastwards to Russia, Kazakhstan, and Mongolia (Kastcheev and Puthz 2011: 443). The species reaches its southernmost limit of distribution in the very north of western Iran (Fig. 11). In view of this distribution pattern, the record by Ghahari et al. (2009a: 1954) from Kaleybar in East Azarbaijan, which is the first record for Iran, can be correct.

The distribution pattern of Stenus crassus cannot be explained by the theory of Pleistocene refuges.

The Holarctic Stenus formicetorum is widely distributed in the temperate and northern Palaearctic as far east as Russian Far East and as far south as Afghanistan and northwestern Iran (Fig. 11).

The wide distribution in the northern and temperate Palaearctic cannot be attributed to a particular Pleistocene refuge.

Unlike other members of the Stenus fornicatus species group which are endemic to the eastern parts of the Palaearctic, S. fornicatus is widely distributed in the West Palaearctic including the Mediterranean and reaches East Siberia. In Iran, the species is hitherto known from the Hyrcanian zone of the northern slopes of the South Caspian mountain ranges only (Fig. 11).

Due to the wide distribution of this species in the Mediterranean, Puthz (2012a: 288) considered Stenus fornicatus to be a Holomediterranean species. Here we follow this interpretation.

Stenus armeniacus was described from Yerevan, Armenia (Puthz 1967: 248), and later recorded from the Kopeh Dag in Turkmenistan and the eastern Zagros Mountains (Arak) in Iran (Puthz 1973: 292). Only recently, Puthz (2012b: 153) published first records of this species from southern Turkey and revealed that the record from Turkmenistan is based on a misidentification. The record from Arak represents the southernmost collection site (Fig. 12). This species is rare and we didn’t succeed in collecting it.

In view of the widely scattered localities in the Irano-Anatolian highlands we propose an Irano-Anatolian type of distribution for Stenus armeniacus.

Stenus hospes is widely distributed in the Mediterranean Region from France and Italy across the Balkans as far east as Anatolia, the Levant, and Caucasia. The recent records from the Zagros Mountains (Fig. 12) constitute the first for the Iranian fauna and considerably extend the known distribution to the southeast.

Judging from its distribution pattern, Stenus hospes can be regarded as a Pontomediterranean species.

Described from the Erzincan Province in the east of Turkey (Korge 1967: 251), Stenus limicola was later recorded for Iran (Smetana 2004: 544) and the north of Iraq (Puthz 2010: 61). We collected S. limicola in the Zagros Mountains and Kerman (Fig. 12). The gap of records between eastern Turkey (Tunceli Province; Anlaş 2009: 280) and the Central Zagros Mountains most probably is a collecting artifact.

Owing to the sparse records of Stenus limicola, it is not possible to explain its Irano-Anatolian distribution pattern with de Lattin’s hypothesis.

Because descriptions of many species of the Stenus glacialis group were based on single specimens and the species never collected again, Assing (2003:711) assumed they inhabit unknown subterranean habitats and are found only by chance. Stenus limicola seems to be restricted to high elevations. In Iran, we collected it between 2860 and 3000 m.

Stenus medus, described from Armenia, Azerbaijan, and northern Iran (Puthz 1981: 702), is widely distributed in Transcaucasia, Turkey, and northern and northwestern Iran between 44°00’E (Orumieh) and 53°00’E (Shahmirzad) (Fig. 12).

Due to its distribution in Transcaucasia and its high abundance in the Hyrcanian zone in the northern slopes of the Elburz Mountains, Stenus medus is a typical expansive Caspian faunal element.

Unlike the other representatives of the Stenus glacialis species group in Iran, S. parcior is widely distributed throughout the Balkans, Anatolia, Cyprus, Lebanon, and Iran as far east as Uzbekistan. The record from Pol-e Dokhtar in the southwestern Zagros Mountains (Puthz 2008: 171) at less than 1000 m elevation constitutes the easternmost record of this species (Fig. 12).

The distribution of Stenus parcior in the eastern Mediterranean and the Middle East corresponds to the expansive Pontomediterranean faunal element.

Stenus persicus seems to be endemic to Azerbaijan and western Iran (Fig. 12). Besides a find in the Ardabil Province, we repeatedly collected it in the Zagros Mountains from Kordestan southwards to northern Fars, usually in higher elevations and sympatrically with relatives of the S. glacialis species group such as S. hospes and S. schah.

Judging from the distribution pattern in the Zagros Mountains and Northwest Iran (Ardabil Province), Stenus persicus can be regarded as an Iranian faunal element.

As far as known presently, Stenus schah is endemic to Iran. The new records, which are the first after the description, revealed its wider distribution in the Zagros Mountains.

The distribution pattern in both the Zagros and Elburz Mountains (Fig. 12) exactly correspond to the Iranian glacial refuge, which is why Stenus schah is an Iranian faunal element.

Stenus erythrocnemus is a Middle Eastern species, which is distributed from Anatolia and Caucasia across the Iranian Plateau eastwards to Kyrgyzstan, Tadzhikistan, Afghanistan, and Pakistan. Stenus erythrocnemus has a vast distribution in the mountain ranges of Iran (Fig. 13).

Because the majority of records originated from the highlands of Iran (Assing 2005: 307), we consider Stenus erythrocnemus to be an expansive Iranian faunal element, which dispersed northwestwards to Anatolia and Caucasia and eastwards to Central Asia and the Hindu Kush.

Stenus maculiger is widely distributed in the Northeast Mediterranean and eastern Europe eastwards to South Russia and Iran. The first records for Iran were published from Ghaemshahr in Mazandaran (Ghahari et al. 2009b: 1964) and Jangal-e Abr in the Semnan Province (Hadian et al. 2011: 4). However, we doubt these records, because we were unable to find this species in the South Caspian mountains. Our collections in Northwest Iran must be regarded as the first confirmed country records (Fig. 13). The locality in the Ardabil Province moreover constitutes the easternmost collecting site of the species.

Judging from the distribution pattern, Stenus maculiger belongs to the expansive Pontomediterranean faunal element.

Stenus fuscicornis is widely distributed throughout most of Europe and the Mediterranean including the Maghreb countries and Turkey. The first record for Iran was published by Puthz (2012a: 312). In Iran, we discovered the species in a relatively small area in the western Elburz and the Talish Mountains (Fig. 14). Unlike most members of the S. hopffgarteni species group which are European endemics, S. fuscicornis is the only representative of the species group in the Middle East. In Iran, the species obviously reaches its eastern limit of distribution.

Stenus fuscicornis is a Holomediterranean species according to Puthz (2012a: 312).

Stenus callidus exists in the Balkans, Caucasia, and the Middle East. According to Puthz (2008: 157), the record for Kyrgyzstan in Smetana (2004: 555), which was adopted by Schülke and Smetana (2015: 810), is based on a misidentification and probably refers to S. cephallenicus. Stenus callidus is the second widespread species of the genus (Fig. 15) in Iran. It was recorded in all of the northwest, in the northern Qohrud Range, and in the Elburz as far east as 53°38’E in eastern Mazandaran. Most frequently, however, it was collected in the Zagros Mountains. The records from southeastern Iran at about 56°E in the provinces of Hormozgan and Kerman considerably extend the range of this species towards east.

Due to its vast distribution in the eastern Mediterranean, Anatolia (Puthz 2008: 153), and Iran, Stenus callidus can be considered as an expansive Pontomediterranean species.

Stenus heinzianus was described from Damash in Gilan, Iran (Puthz 1970a: 223), and subsequently recorded from Azerbaijan and Afghanistan. In Iran, it is abundant in the entire Hyrcanian zone from northern Gilan as far east as Golestan (Fig. 16).

Judging from this distribution pattern, Stenus heinzianus is an expansive Caspian faunal element.

Stenus taurus was described only recently from westerly facing slopes of mountain ranges close to the Turkish border in West Azarbaijan (Serri and Frisch 2013: 99–103; Fig. 16).

It is difficult to assign Stenus taurus to a particular distribution type, because its total distribution is still unknown. However, we expect it to be endemic to the Irano-Anatolian highlands.

Stenus latifrons is widely distributed across Europe from the Balkans and Italy northwards to Scandinavia. Towards the east, the species reaches Turkey, Caucasia, and Iran. A recent record from Kazakhstan (Kastcheev and Puthz 2011: 447) is based on a single female. In Iran, the species is known from the Caspian plain in Gilan (Fig. 17).

Kastcheev and Puthz (2011: 454) consider Stenus latifrons to be a Mediterranean species. In view of the absence in the western Mediterranean, we follow Puthz (2012a: 287) and attribute the species to the Pontomediterranean type of distribution.

Stenus incrassatus is widely distributed in the northern and temperate Palaearctic from Ireland to China and Russian Far East. In Iran, we collected S. incrassatus only in the Talish Mountains (Fig. 17) from sea level up to 1850 m.

The vast range of the trans-Palaearctic species cannot be attributed to a particular Pleistocene refuge in the West Palaearctic and Middle East, respectively.

Stenus morio is a Holarctic species with a trans-Palaearctic distribution. The first records for Iran (West and East Azarbaijan) were published only recently by Ghahari et al. (2009b: 1964). However, we were not given the opportunity to see the underlying specimens. Like other members of the S. melanarius group, S. morio seems to be rare in Iran and restricted to the northwest of the country, because we collected it in the northern Zagros (Hamedan Province) only (Fig. 17).

The trans-Palaearctic distribution of Stenus morio can not be explained by particular Pleistocene refuges.

Stenus peripherus was described as a subspecies of S. melanarius from Turkey (Korge 1971: 24), but only recently raised to species rank by Puthz (2008: 149). The species is distributed in eastern Turkey, Armenia, and Iran, where it reaches its southernmost known limit of distribution in the southern Talish at 36°54’N, 49°59’E (Fig. 17).

The few localities hitherto known suggest an expanded Caspian distribution for Stenus peripherus.

The West Palaearctic Stenus atratulus is widely distributed throughout Europe, the Mediterranean including the Maghreb countries Algeria and Tunesia, and Turkey eastwards to Iran, where it is most abundant in the northwest (Fig. 18), from where it dispersed across the South Caspian mountains as far east as the Koppeh Dag at about 58°E in North Khorasan, the easternmost confirmed locality of the species. Interestingly, S. atratulus was not found in the Zagros Mountains south of Hamedan Province, but it occurs in the dryer Qohrud Range, where we recorded it at Shir Kuh and in the mountains of Kerman (Fig. 18).

Due to its Mediterranean distribution centre, we classify Stenus atratulus as a Holomediterranean species following Puthz (2012a: 78).

Stenus piscator is distributed from the eastern Mediterranean (Turkey, Cyprus, Levant) across Anatolia and northern Mesopotamia as far north as Transcaucasia and eastwards to Iran and Turkmenistan. In Iran, the species has a disjunct distribution pattern (Fig. 18) and is recorded for the Talish, the Turkmeno-Khorasanian mountains, the southern Zagros, the plain of Khuzestan, and Kerman. Stenus piscator reaches its easternmost known locality in the Koppeh Dagh at about 58°30’E.

The arched distribution pattern west, north, and east of Mesopotamia characterizes Stenus piscator as an expansive Syrian faunal element.

Described as a subspecies of Stenus mendicus from Israel (Puthz 1964: 229), S. alienigenus is distributed in the Levant (Lebanon, Israel and Syria) and Iran, where it seems to be restricted to the northern Zagros Mountains (Fig. 19).

Due to its distribution in the arboreal regions west and east of the Mesopotamian plain, we consider Stenus alienigenus as a Syrian faunal element.

Stenus ignotus was described from the Talish Mountains near Lenkoran, Azerbaijan (Eppelsheim 1890: 226). Its area of distribution reaches from Italy and the Balkans over Anatolia, Syria, Iraq, Caucasia, and Iran eastwards to Central Asia. In Iran, S. ignotus is distributed in the very northwest, the northern Zagros Mountains, and the South Caspian mountains, where we recorded it as far east as about 53°30’E in eastern Mazandaran (Fig. 19).

Judging from the wide distribution in the northeastern Mediterranean, Stenus ignotus belongs to the Pontomediterranean type of distribution.

Stenus orientis is restricted to the Levant, Iraq, and western Iran, where it is recorded in the South Caspian mountains as far east as about 53°30’E (eastern Mazandaran) and in the Zagros Mountains southwards to 29°24’N (Central Fars) (Fig. 19).

Due to this arched distribution around the northern Mesopotamian plain, we consider Stenus orientis as a Syrian faunal element.

Stenus barbarae was described from the Talish Mountains in Gilan, Iran (Hromadka 1979: 183). The new record close to the type locality is the first after the description. As far as known presently, S. barbarae is endemic to some north-facing valleys in the southern Talish at about 37°N, 49°E (Fig. 20).

Stenus confrater is endemic to the northern Talish Mountains in Iran and Azerbaijan (Fig. 20). In Gilan, it was collected at an elevation of 30 m only in the foothills of the Talish Mountains. In higher elevations, the species seems to be replaced by its close relatives S. barbarae and S. darius.

As far as known presently, Stenus darius is endemic to the northeast-facing freshwater system of the Masuleh Valley in the southern Talish Mountains at about 37°N, 49°E (Fig. 20).

Stenus derwisch is a Hyrcanian endemic, which is comparatively widespread in the South Caspian mountains (Fig. 20). The species is hitherto recorded from the very north of Gilan at 38°13’N, 48°53’E (Astara) eastwards to Central Mazandaran at about 52°20’E (Amol).

Stenus guilanensis was described from Lahijan, Gilan (Puthz 1979: 57). The Hyrcanian endemic is hitherto known only from the type locality in the northwesternmost foothills of the Elburz (Fig. 20).

Stenus kambyses is presently known only from the type locality in the southernmost Talish Mountains, Gilan (Fig. 20), and certainly endemic to the Hyrcanian district.

Including the new records from western Mazandaran, the first after the description, Stenus martensi is endemic to the Hyrcanian forest zone of the Elburz, where it was collected between 50°34’E (Ramsar) and 52°49’E (Alasht) in altitudes up to 1450 m (Fig. 20).

Stenus ochropus is the most widespread member of the ochropus-ludyi-coarcticollis species group. The West Palaearctic species is distributed from Europe, except for the Iberian Peninsula, as far east as Central Asia including Anatolia, the Levant, Caucasia, and Iran, where it is recorded from the northwest as far east as Tehran and southwards to 29°09’N in Fars (Fig. 20).

Judging from its wide distribution in the northeastern Mediterranean, we follow Puthz (2012a: 313), who classified Stenus ochropus as an expansive Pontomediterranean species.

Stenus pieperi was described from Alamdeh, West Mazandaran (Puthz 1983: 353). Our recent records further east, which are the first after the description, indicate that the species is endemic to the Hyrcanian forest zone of the Elburz Mountains from about 50°30’E eastwards to about 53°10’E (Fig. 20)

Stenus ressli was described from the northern foothills of the Elburz in the Caspian plain south and east of Chalus (Puthz 1979: 54). We rediscovered it somewhat further to the west south of Tonekabon. Seemingly, S. ressli is endemic to a small area in the Hyrcanian forest belt of western Mazandaran (Fig. 20).

Stenus wittmeri, described from Minudasht, Golestan (Puthz 1972a: 123), is the easternmost representative of the S. ochropus-ludyi-coarcticollis species group in Iran. The species is endemic to the Hyrcanian forest belt of the eastern Elburz (Fig. 20).

The Middle Eastern Stenus arabicus is recorded from Lebanon, Israel, Jordan, Syria, Turkey, and Iran as far north as Armenia. The record from China in Smetana (2004: 552), which was repeated by Schülke and Smetana (2015: 805), is a lapsus (V. Puthz, pers. comm.). We collected the species in two widely separate localities in the Zagros Mountains (Fig. 21).

Due to its arched distribution in arboreal regions around northern Mesopotamia, Stenus arabicus can be considered as a Syrian faunal element.

The West Palaearctic Stenus butrintensis was previously known from western Europe as far east as Turkey. The record for Spain in Smetana (2004: 552), adopted by Schülke and Smetana (2015: 810), is a lapsus (Puthz 2012a: 310). The first record of S. butrintensis for Iran in the Central Zagros considerably extends the known limit of distribution to the southeast (Fig. 21).

Due to its wide distribution in the northeastern Mediterranean, we adopt Puthz’ (2012a: 310) classification as a Pontomediterranean species.

Described from Lenkoran, Azerbaijan (Puthz 1971: 100), Stenus claritarsis is distributed from eastern Europe (Austria, northern Balkans, Ukraine, South Russia) across Caucasia and Iran eastwards to Central Asia. In Iran, the species is widespread in the South Caspian mountains, where we collected it as far east as 51°29’E in western Mazandaran and in the Zagros Mountains southwards to 28°45’N in southeastern Fars. It was also found in the plain of Khuzestan (Fig. 21).

Puthz (2012a: 312) proposed a Ponto-Mediterranean distribution for Stenus claritarsis, which is unlikely in view of the lack of records in all of the eastern Mediterranean. The distribution across Transcausasia and the South Caspian mountains points to an expansive Caspian faunal element.

Stenus ganglbaueri is distributed from Italy and the Balkans across Ukraine, Anatolia, the Levant, Syria, Caucasia, and Iran eastwards to Turkmenistan. The species is widespread in northern Iran as far east as the Binalud Mountains (Fig. 22), but a find in Kerman Province, which considerably extends the known range of S. ganglbaueri to the south, suggests a much wider distribution in the western Iranian Plateau.

Due to its distribution in the southeastern Mediterranean, we consider Stenus ganglbaueri to be a Pontomediterranean faunal element.

Stenus picipes is widespread in the temperate West Palaearctic as far east as western Russia, Anatolia, the Levant (Lebanon, Jordan, Syria), and Iran. The records from the northwestern Zagros Mountains (Puthz 2010: 61), the first for Iran, mark the southeastern distributional limit of this species (Fig. 22). The specimens from Iran belong to the type form S. p. picipes, which differs from S. p. brevipennis Thomson, 1851 by broader elytra with well developed humeral angels. These sympatrical morphs are formally treated as subspecies in recent catalogues (Schülke and Smetana 2015: 835, 836) and key books (Puthz 2012a: 309).

The wide area of distribution of Stenus picipes can not be attributed to particular Pleistocene refugia of the arboreal, which is why no biogeographical assigning is possible for this West Palaearctic species.

Stenus lenkoranus was described as a subspecies of S. nanus Stephens, 1833 (Puthz 1970b: 211), but later raised to species rank (Ryvkin 1990: 158). The species is hitherto known from Azerbaijan and Iran only. The first records for Iran originate from the South Caspian mountains, Mt Sabalan in West Azarbaijan, and the northwestern Zagros in Ilam (Fig. 23).

We propose an expansive Caspian distribution for Stenus lenkoranus.

Stenus machulkai, described from the Araxes Valley (Hromadka 1977: 4), is known from Caucasia (Azerbaijan, Armenia, Georgia), Lebanon, Turkey, and Iran. The species is widely distributed in the northwest of the country, the northern and central Zagros, and the South Caspian mountains, where it is recorded as far east as 55°46’E (Fig. 23).

Judging from its existence in the northeastern Mediterranean, Stenus machulkai can be attributed to the Pontomediterranean type of distribution.

Stenus viti, endemic to the northern slopes of the South Caspian mountains and presently known from Iran only, is recorded from northern Gilan at 48°49’E (Astara) throughout Mazandaran eastwards to Golestan at 55°14’E (Ramian) (Fig. 23).

This species is a Hyrcanian faunal element sensu De Lattin (1951: 208–210, 1957: 388, 1967: 322).

Described from Aulie Ata (Taraz) in southern Kazakhstan, the Central Asian Stenus bernhauerianus was also recorded from Kyrgyzstan and the Koppeh-Dagh (Fig. 24) in the northeast of Iran (Puthz 2010: 60).

Due to its distribution pattern, this rare species can be regarded as a Turkestanian faunal element.

The Euro-Siberian Stenus cicindeloides has a trans-Palaearctic distribution from the British Isles east to Japan. The species is here for the first time reported for Iran from Ardabil and Mazandaran in the northwest of the country (Fig. 24).

It is not possiblt to assign the distribution pattern of Stenus cicindeloides to any of de Lattin’s (1951, 1957, 1967) southern Palaearctic glacial refuges.

Stenus similis is widely distributed throughout the West Palaearctic eastwards to Kazakhstan and Mongolia. The species exists in northwestern Iran and was recorded as far south as 30°44’N in the Zagros Mountains (Fig. 24).

Judging from the existence in all of the arboreal Mediterranean, Stenus similis belongs to the Holomediterranean type of distribution.

East Azarbaijan: Arasbaran, 8.2005 (Samin et al. 2011a: 2). West Azarbaijan: Maku, 9.2007 (Samin et al. 2011c: 1238).

The distribution of the widespread Holomediterranean Stenus aceris is confirmed as far east as Cyprus, Lebanon, and Turkey. The existence in northwestern Iran is doubtful.

Gilan (Samin et al. 2011 b: 140).

The Palaearctic distribution of the Holarctic Stenus a. assequens reaches from Western Europe and the arboreal North Africa eastwards to the Russian Far East and China. Puthz (1977: 111) wrote that he received a single female from Nav Valley, Gilan, but this record was not adopted by Schülke and Smetana (2015: 806). Owing to the existence of S. a. assequens in Caucasia, Turkey, and Central Asia, the above record for Gilan could be correct.

West Azarbaijan: Mahabad, 9.2003 (Ghahari et al. 2009a: 3). Semnan: Jangal-e Abr, 4.-5.2011 (Hadian et al. 2011: 3).

Stenus binotatus is widely distributed across the Palaearctic from the British Isles to East Siberia. According to Kastcheev and Puthz (2011: 440), the record for Kazakhstan in Smetana (2004: 552), which was not repeated by Schülke and Smetana (2015: 808), is based on a misidentification. In view of the distribution in Caucasia and Turkey, the existence of S. binotatus in Iran is conceivable.

Golestan: Kordkoy, 6.2005 (Ghahari et al. 2009b: 1964). Semnan: Shahrud, 4.2009 (Hadian et al. 2011: 4).

Stenus circularis is widely distributed throughout Europe and western Asia as far east as Turkey, Caucasia, West Siberia, and Central Asia. In view of this West Palaearctic distribution pattern the above records could be correct.

Samin et al. (2011b: 141) erroneously misinterpreted Puthz (1972a: 125, 1972b: 280), who mentioned “Stenus cordatoides variant A” from Esfahan Province, which the same author later described as S. turk (Puthz 1972: 178). Therefore the Pontomediterranean S. cordatoides, which is distributed in the Balkans, Turkey, and the Levant, does not belong to the Iranian fauna. Schülke and Smetana (2015: 813) do not cite the species for Iran.

East Azarbaijan: Arasbaran (Sakenin et al. 2008).

Stenus cyaneus is distributed in Lebanon, Israel, Jordan, Syria, and Turkey. Sakenin et al. (2008) recorded the species for Iran as S. glacialis cyaneus, because until recently it was considered as a subspecies of the Central and Southeast European S. glacialis Heer, 1839. The existence of S. cyaneus in Iran is conceivable.

Sistan & Baluchestan (Samin et al. 2011b: 141).

This record was adopted from Scheerpeltz (1961: 4), though it already turned out to be based on a misidentification (Herman 2001: 2208). Consequently, the Holomediterranean S. guttula, which is widely distributed in Europe and the Mediterranean, but also recorded for Egypt (Sinai) and Yemen, does not exist in Iran.

Samin et al. (2011b: 141) cited Stenus m. melanarius for Iran referring to the catalogues of Herman (2001: 2276) and Smetana (2004: 559). The underlying specimens represent S. peripherus Korge, 1971 (Puthz, pers. comm.). Thus, the trans-Palaearctic S. melanarius is not yet recorded for the fauna of Iran. This erroneous record is, however, cited by Schülke and Smetana (2015: 828) again.

Razavi Khorasan: Mashad, 3.2006 (Samin et al. 2011c: 1238). South Khorasan: Birjand, 6.2001 (Samin et al. 2011a: 3).

The Holarctic Stenus melanopus is widely distributed throughout the western Palaearctic eastwards to China. The cited records from Northeast Iran are dubious as well as an old record from “Perse méridionale” (Fauvel 1873: 256), because, except for Turkey, the species is unknown from the Middle East and Central Asia.

Ardabil: Ardabil, 6.2004 (Ghahari et al. 2009a: 1954). Semnan: Shahrud, 11.2010 (Hadian et al. 2011: 4).

The area of distribution of the Pontomediterranean Stenus paludicola stretches over the Balkans, Anatolia, and the Levant. The existence in northwestern Iran is imaginable.

Gilan: Rasht (Jarrige 1971: 498; cited by Samin et al. 2011b: 142).

The area of distribution of Stenus pallitarsis stretches over the arboreal Palaearctic eastwards to East Siberia and China. In view of the distribution in Caucasia, Turkey, and Central Asia, the existence in Iran is conceivable.

Iran (Schülke and Smetana 2015: 835).

Stenus picipennis is widely distributed in Europe and the Mediterranean, but unknown from Turkey, the Levant, and Caucasia. In view of this distribution pattern the record for Iran in the current edition of the Catalogue of Palaearctic Coleoptera far east of the area of distribution of S. picipennis appears doubtful. The underlying reference for this country record, which was not yet cited in the first edition of the catalogue (Smetana 2004: 552), is unknown to us.

Semnan (Sakenin et al. 2010: 13).

The nominotypical form of Stenus planifrons has a Pontomediterranean distribution in southeastern Europe and Turkey. Considering the allopatry of subspecies, the record from Semnan is implausible, because the collecting site is situated deeply within the area of distribution of S. planifrons robustus in northwestern Iran and the South Caspian mountains (Fig. 7).

East Azarbaijan: Arasbaran (Sakenin et al. 2008).

This species was described from Afghanistan (Scheerpeltz 1960: 74) and since then never recorded again. Its existence in East Azarbaijan is doubtful.

Esfahan: Lenjan, 8.2000 (Ghahari et al. 2009b: 1964). Semnan: Garmsar, 3.2011 (Hadian et al. 2011: 4).

Stenus pusillus is widely distributed across Europe and the arboreal North Africa (Morocco). As the species was never recorded for western Asia and the Middle East, respectively, the presence in Iran is implausible.

Fars: Kazerun, 10.2002 (Samin et al. 2011a: 3); Shiraz, 5.2008 (Samin et al. 2011c: 1238).

The area of distribution of the West Palaearctic Stenus solutus stretches from the British Isles as far east as Anatolia and Azerbaijan. Its existence in South Iran is doubtful.

East Azarbaijan: Kaleybar, 8.2006 (Ghahari et al. 2009a: 1954). Semnan: Jangal-e Abr, 4.2011 (Hadian et al. 2011).

In view of the confirmed distribution of the Pontomediterranean Stenus stigmula in Turkey and Transcaucasia, the records from northwestern Iran are plausible.

Ardabil: Meshkinshahr, 6.2007 (Samin et al. 2011c: 1238). East Azarbaijan: Arasbaran, 8.2005 (Samin et al. 2011a: 3).

Stenus subaeneus is widely distributed throughout the arboreal Mediterranean and Europe as far east as Lebanon, Syria, and Turkey. The records from northwestern Iran are questionable.

Semnan (Sakenin et al. 2010).

Stenus turbulentus has a restricted distribution in Greece, Turkey, Cyprus, and Israel. The existence of this species in North Iran is doubtful.

Khuzestan: Ahvaz, 4.2007 (Samin et al. 2011c: 1238); Dezful, 5.2003 (Samin et al. 2011a: 3).

Remarks: In view of the restricted distribution of Stenus umbricus in France (Corse), Switzerland, and Italy, the record from Khuzestan is certainly based on a misidentification and here rejected.