taxonID	type	description	language	source
CE0987BD7F5AFF90FF21FB42555E5E83.taxon	description	Figs 1 – 3, 6,7, 9 – 16	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5AFF90FF21FB42555E5E83.taxon	materials_examined	TYPE MATERIAL. Holotype – ♂, Indonesia: Sumatra Island, North Sumatra Prov., env. of Bukit Lawang Vill. [03 ° 33 ʹ N, 98 ° 07 ʹ E], 250 m, hand picking from web in small grottos, 1988 (precise date unknown), unknown collector (ZMMU). Paratypes: 2 ♂, same place and data (ISEA 001.8985).	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5AFF90FF21FB42555E5E83.taxon	diagnosis	DIAGNOSIS. By palp structure (cymbium dorsally with dense scopula, shape of tegulum, embolus, conductor and sperm duct) males of P. leshukovi sp. n. are most similar to those of P. singaporensis Thorell, 1894 (cf. Figs 9 – 16 and 15 a – d, 84 h in Bayer (2012 )). The new species can be easily distinguished from the latter by long, thin, noticeably curved embolus (E) (vs. short, thick, almost straight), extending to the anterior edge of conductor (C) (vs. not reaching), base of embolus (EB) in ventral view 4 times broader than embolus itself (vs. 1.2 times), and conductor Ɔ-shaped (vs. C-shaped) in ventral view (left palp) and strongly curved in retrolateral view (vs. not curved).	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5AFF90FF21FB42555E5E83.taxon	description	DESCRIPTION. Male (holotype). Body and eye measurements. Total length 10.59, carapace length 4.66, carapace width 2.88, anterior width of carapace 1.49, opisthosoma length 5.88, opisthosoma width 2.05. Eyes: AME 0.37, ALE 0.36, PME 0.34, PLE 0.29, AME – AME 0.10, AME – ALE 0.03, PME – PME 0.18, PME – PLE 0.22, AME – PME 0.26, ALE – PLE 0.28, clypeus height at AME 0.39, clypeus height at ALE 0.33. Carapace yellow with narrow (ca. 1 x diameter of PME), gray, slightly serrated lateral bands. Median band gray with yellow mark anteriorly, slightly serrated. Chelicerae yellowish with 3 promarginal and 4 retromarginal teeth. Maxillae light brown. Sternum yellowish at lateral margins with dark brown, triangle patch centrally. Legs and palps yellow, with vague dark annulations. Opisthosoma dorsally yellowish (grayish posteriorly), laterally grayish, ventrally light brown with narrow, yellow and black longitudinal line. Measurements of palp and legs. Palp: 5.49 [1.79, 1.03, 0.86, 1.81]; Legs: I 56.75 [15.34, 1.87, 15.85, 16.49, 7.20], II 41.04 [11.06, 1.58, 10.65, 11.76, 5.99], III 27.03 [7.62, 1.35, 6.71, 7.53, 3.82], IV 45.23 [12.52, 1.52, 11.22, 13.59, 6.38]. Spination. Palp: 1410, 0000, 0000 (all palpal tibia spines small, some of them are setae-like); legs: femur I 6560, II 7650, III 5430, IV 5730; patella I – IV 0000; tibia I 3049, II 2036, III 3235, IV 3035; metatarsus I 3036, II 3036, III 3036, IV 4035. Macrosetae ventrally on coxae I and trochanter I-II present, well developed (Fig. 6). Palp as in Figs 9 – 16. Femur modified with a flat ventral bulge (FB). Cymbium (length / width ratio ca. 3.9) dorsally with scopula (CS), covering almost half of cymbium. Conductor (C) wide, hyaline, poorly visible when bulbus not cut off from cymbium. Conductor 1.5 times wider in middle part, than at its base, strongly curved in pro- and retrolateral view. Embolus (E) long (about 1 / 3 of tegulum length) with broad base (EB) in ventral view. Female unknown.	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5AFF90FF21FB42555E5E83.taxon	biology_ecology	BIOLOGY. Psechrus leshukovi sp. n., similar to many of its congeners appears to be a hemitroglobionts, meaning it is found both in caves and similar habitats without specific morphological adaptations to cave conditions (Birshtein, 1985). NOTES. Based on the structure of its male palp, coloration, and legs spination P. leshukovi sp. n. belongs to P. singaporensis - group. Thus, this group comprises five species: P. arcuatus Bayer, 2012, P. elachys Bayer, 2012, P. leshukovi sp. n., P. norops Bayer, 2012 and P. singaporensis. Two species of the group (P. arcuatus and P. singaporensis) are known from Sumatra, other from Malaysian Peninsula and Thailand. It is worth noting that Bayer (2012) reported P. singaporensis from Bohorok Town [03 ° 31 ʹ N, 98 ° 09 ʹ E], which is in close proximity to Bukit Lawang Village (the distance is ca. 5 km). Bayer mentioned this record based on several female and juvenile specimens as doubtful. There is a high probability that these females from Bohorok Town actually belong to P. leshukovi sp. n. Specimens from Bohorok Town are stored in Nationaal Natuurhistorisch Museum Naturalis in Leiden (Netherlands) (RMNH). We don’t have the opportunity to study them.	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5AFF90FF21FB42555E5E83.taxon	distribution	DISTRIBUTION. Type locality only (Figs 20, 21).	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5AFF90FF21FB42555E5E83.taxon	etymology	ETYMOLOGY. The specific name is a patronym in honor of Ivan Leshukov (Jakarta, Indonesia), Russian biologist and tourist guide working in Indonesia.	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5DFF92FF21FAC750A958B0.taxon	description	Figs 4, 5, 8, 17 – 19	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5DFF92FF21FAC750A958B0.taxon	materials_examined	MATERIAL EXAMINED. Indonesia: Sumatra Island, North Sumatra Prov., env. of Bukit Lawang Vill. [03 ° 33 ʹ N, 98 ° 07 ʹ E], 250 m, hand picking from web in small grottos, 1988 (precise date unknown), unknown collector, 1 ♀ (ISEA 001. 8986).	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5DFF92FF21FAC750A958B0.taxon	diagnosis	DIAGNOSIS. The female of P. libelti is most similar to those of P. argentatus (Doleschall, 1857) in having broad and flat copulatory ducts (CD) and receptacle heads (RH) on long stalks but can be distinguished from it by septum (S) approximately as long as wide (vs. twice wider than long) and converging lateral margins (LM) (vs. parallel) (cf. Figs 17 – 18 and fig. 2 g in Bayer (2012 )). Endogyne of both species are nearly indistinguishable.	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5DFF92FF21FAC750A958B0.taxon	description	REDESCRIPTION. Female. Body and eye measurements. Total length 19.7, carapace length 7.0, carapace width 5.3, anterior width of carapace 3.1, opisthosoma length 14.0, opisthosoma width 6.7. Eyes: AME 0.43, ALE 0.46, PME 0.49, PLE 0.44, AME – AME 0.29, AME – ALE 0.13, PME – PME 0.21, PME – PLE 0.4, AME – PME 0.49, ALE – PLE 0.57, clypeus height at AME 1.09, clypeus height at ALE 0.93. Carapace and chelicerae light brown. Chelicerae with 3 promarginal and 3 retromarginal teeth. Maxillae brown, darker distally. Sternum brown, with light setae at the edges. Legs and palps light brown with vague dark annulations. Opisthosoma cream-colored dorsally, ventrally brown, with narrow, white and dark brown longitudinal line. Measurements of palp and legs. Palp: 9.4 [3.0, 1.3, 1.7, 3.4]; Legs: I 57.6 [16.3, 3.5, 16.2, 15.3, 6.3], II 42.1 [12.5, 3.0, 11.0, 11.0, 4.6], III 28.9 [8.9, 2.3, 7.0, 7.3, 3.4], IV 43.2 [13.0, 2.6, 11.0, 11.4, 5.2]. Spination. Palp: 1310, 1400, 2100, 2210; Legs: femur I 7770, II 7670, III 6560, IV 6740; patella I – IV 0000; tibia I 3034, II 3036, III 3135, IV 3034; metatarsus I 3035, II 3035, III 3035, IV 3034. Epigyne structure (Figs 17 – 19). Epigynal plate (EP) 3 times longer than septum (S). Septum trapezoidal, nearly as long, as wide. Lateral margins (LM) converging. Epigynal muscle sigilla (EM) adjoining to epigynal plate. Copulatory ducts (CD) twice wider than receptacle base (RB). Spermathecal bases bent anteriad. Stalks of receptacle heads (RH) approximately twice shorter than receptacle bases. Receptacle heads bear distinct glands.	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5DFF92FF21FAC750A958B0.taxon	biology_ecology	BIOLOGY. The same is in P. leshukovi sp. n. NOTES. At the beginning of this research we initially believed that the treated female belonged to P. leshukovi sp. n. Later, after studying vulva of this specimen we concluded that it belongs to another species, even from a different species group. We identified this female as P. libelti, species described from Palembang (Sumatra). This case highlights that different species of Psechrus are able to inhabit the same cave, leading to the potential mismatching of males and females during the description of new species. A similar example of such syntopy, where two different species of Psechrus belonging to different species groups is already known from Laos. Psechrus laos Bayer, 2012 and P. luangprabang Jäger, 2007 were recorded from the same cave in Lak Sao [18 ° 13 ʹ 38.2 ʹʹ N, 104 ° 44 ʹ 47.3 ʹʹ E] (Bolikhamsay Province) (Bayer, 2012). Thereby, repeatedly discovered syntopy / cohabitation of Psechrus species, combined with high diversity of this genus, should make the taxonomists working on this group careful when describing new species or missing sexes. Currently, about a quarter of Psechrus species (15 species out of 57) are known based on only one sex (WSC, 2023).	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
CE0987BD7F5DFF92FF21FAC750A958B0.taxon	distribution	DISTRIBUTION. Distributed in Malay Peninsula and Sumatra and Kalimantan Islands (Bayer, 2012).	en	Omelko, M. M., Fomichev, A. A. (2023): Two species of the genus Psechrus Thorell, 1878 (Araneae: Psechridae) from North Sumatra, Indonesia. Far Eastern Entomologist 482: 1-9, DOI: 10.25221/fee.482.1, URL: http://dx.doi.org/10.25221/fee.482.1
