Leptothele bencha Raven & Schwendinger 1995
Creators: name: Schwendinger, Peter J.
name: Lehmann-Graber, Christina
name: Hongpadharakiree, Komson
name: Syuhadah, Nurul
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Dipluridae
Leptothele
Leptothele bencha

description: Leptothele bencha Raven & Schwendinger, 1995
Figs 1 E-F, 3-4
Leptothele bencha Raven & Schwendinger, 1995: 637-639, figs 2C, 3E-F, 4E, 5F-G, 9 (description of males and females).
Holotype: QMS 29275; male; THAILAND, Krabi Province, Khao Phanom Bencha National Park, near Huay To Waterfall, 8°14’16”N, 98°55’02”E, 260 m; 21.IX.1992; leg. P.J. Schwendinger.
Paratypes: QMS 29276; 3 females; same data as for holotype. – MHNG; 1 male and 1 female; same data as for holotype.
Other material examined: MHNG (sample THMA- 00/14); 5 males (matured 17.VIII.2000, 24.IX.2000, beginning XII.2000), 11 females; THAILAND, Phuket Province, Ko Sirey, 7°53’10”N, 98°26’11”E, 50 m; 12.VIII.2000; leg. P.J. Schwendinger. – MHNG (sample TH-02/11); 1 male, 1 female; Ko Sirey, 30 m; 22.VIII.2002; leg. P.J. Schwendinger. – MHNG; 4 females; THAILAND, Krabi Province, Khao Phanom Bencha National Park, near Huay To Waterfall (the type locality), 260 m; 21.IX.1992; leg. P.J. Schwendinger. – MHNG (sample THA-99/1); 1 female; THAILAND, Krabi Province, Khao Phanom Bencha National Park, near Huay To Waterfall, 8°14’24”N, 98°54’56”E, 100- 190 m; 11.X.1999; leg. P.J. Schwendinger. – MHNG (sample TH-07/10); 5 females; THAILAND, Phang Nga Province, Ko Yao Noi, 8°11’04”N, 98°38’02”E, 70 m; 16.VII.2007; leg. P.J. Schwendinger. – MHNG (sample TH-06/07); 2 males (one of them matured XII.2006), 2 females; THAILAND, Ko Yao Noi, near Ban An Pao, 8°09’53”N, 98°37’20”E, 150 m; 21.IX.2006; leg. P.J. Schwendinger. – MHNG (sample THMA- 08/10); 2 females; THAILAND, Krabi Province & District, Khlong Jilat, 8°05’18”N, 98°52’56”E, 60 m; 16.VI.2008; leg. P.J. Schwendinger. – MHNG (sample THMA-08/07); 1 male (hatched VIII.08, matured end XII.09), 4 females; THAILAND, Krabi Province & District, Thab Khaek - Hang Nak Hill, near waterfall, 8°05’43”N, 98°45’11”E, 300 m; 13.VI.2008; leg. P.J. Schwendinger. – MHNG (sample TH-09/09); 1 female; THAILAND, Krabi Province & District, Ban Chong Phlie, 8°04’50”N, 98°49’50”E, 80 m; 13.VI.2009; leg. P.J. Schwendinger. – MHNG (sample THA-99/3); 3 males (hatched end XII.1999; matured 18.VI.2000, VII.- VIII.2000, IX.2000), 9 females; THAILAND, Krabi Province, Ko Lanta, 7°28’36”N, 99°05’25”E, 5 m; 15.X.1999; leg. P.J. Schwendinger. – MHNG (sample TH-09/03); 2 females; THAILAND, Trang Province, Ko Muk, near Morakot Cave, 7°21’52”N, 99°17’30”E, 60 m; 28.V.2009; leg. P.J. Schwendinger. – MHNG (sample TH-05/09); 4 males (one collected mature, others matured 16.IX.2005, 7.X.2005, 9.XI.2005), 11 females; THAILAND, Trang Province, Ko Libong, near Ao Tokae, 7°16’04”N, 99°22’39”E, 30 m; 20.VII.2005; leg. P.J. Schwendinger. – MHNG (sample TH-09/02); 1 male, 10 females; THAILAND, Trang Province, Ko Sukon, 7°05’51”N, 99°34’53”E, 140 m; 23.V.2009; leg. P.J. Schwendinger. – MHNG; 6 males (matured 13.II.1996, 20.IX.1996, 13.VI.1997, 10.VII.1997, 22.VIII.1997, 27.VIII.1997), 12 females; THAILAND, Satun Province, Ko Tarutao, 6°40’60”N, 99°38’47”E, 30 m; 12.I.1996; leg. P.J. Schwendinger. – THNHM; 1 male (matured 10.IX.1996), 1 female; THAILAND, Satun Province, Ko Tarutao, 30 m; 12.I.1996; leg. P.J. Schwendinger.
Extended diagnosis: Distinguished from L. chang sp. nov. by smaller size and darker body colour. Males with shorter bulbous part of palpal organ (Fig. 3A, D, G, H cf. Fig. 6 A-E), normally only with two ventral megaspines [Fig. 3C, F (one exception with four megaspines, Fig. 3J); 2-3 megaspines in L. chang sp. nov., Fig. 6 H-K] and without wrinkles behind and in front of subdistal ventral ridge on tibia II (Fig. 3C, F, J; present in L. chang sp. nov., Fig. 6 H-K), and with a more distinct, conical ventral process on metatarsus II (Fig. 3B, E, I cf. Fig. 6G). Females with longer and narrower spermathecal trunks and with much shorter stalks of median receptacles (Fig. 4 cf. Fig. 7).
Variation: Carapace lengths in males (n = 25) range 1.52-2.04, carapace widths 1.29-1.78. The smallest male examined is the paratype deposited in the MHNG, the largest male is from Thab Khaek - Hang Nak Hill. The largest female (from Khlong Jilat) has a 2.94 long and 2.49 wide carapace. Among the 25 males examined 24 have two ventral megaspines on the tibiae of both legs II. Only a single male (from Ko Sukon) has a relatively low ventral spur carrying four megaspines on its left tibia II (Fig. 3 I-J), which is clearly abnormal; its right tibia II is equipped with a more elevated (i.e. normal for this species) ventral spur carrying two megaspines. The holotype (not re-examined) appears to lack any proximal spines on the ventral side of metatarsus I of at least the right leg (Raven & Schwendinger, 1995: 638, fig. 9F), but all males examined for this study (including a paratype) have 1-2 weak spines at that position. A male from Ko Libong has a slightly longer bulbal part of the palpal organ (Fig. 3H) than the other conspecific males examined.
The vulvae of two females from Ko Siray (the northernmost locality of this species; Fig. 4 E-F) have median receptacles with relatively smaller heads and much longer stalks, as well as lateral receptacles with a much narrower apex than females from the other localities (Fig. 4 A-D). Despite these quite pronounced differences in female genitalia, the males from Ko Siray show no relevant distinctions from the other males examined (Fig. 3 A-B cf. Fig. 3 C-J). We consider this as a geographical form that does not deserve specific or subspecific rank.
Remark: The “small pointed protuberances” on the spermathecae and receptacles of two paratypes shown in Raven & Schwendinger (1995: 638, fig. 9J-K) are actually the cuticular bases of gland ducts that empty through pores into the interior of the spermathecae (see also Schwendinger & Ono, 2011: figs 56-58, 61-64). These gland duct bases are clearly visible on exuviae (Fig. 7A, showing L. chang sp. nov.), but not on unstained vulvae dissected from specimens (only the pores are visible there, Fig. 4, see also Fig. 7 B-D showing L. chang sp. nov.). These protuberances thus have no or only very limited taxonomic value.
Distribution: This species is known from 11 localities near the Andaman coast of southern Thailand (Fig. 2, localities 1-10, 4 refers to two nearby localities). Four sites (including the type locality) lie on the mainland in Krabi Province, on or near the coast, the others are on islands quite close to the mainland (the most distant is Ko Tarutao, about 17 km offshore, Fig. 2, locality 10). Despite extensive sieving of forest litter on Phuket Island and at numerous additional forest sites in southern Thailand, no other conspecific specimens were collected.
Biology: Most spiders examined were collected by sieving leaf litter in semi-evergreen rain forests. At Thab Khaek - Hang Nak Hill they were found in tiny tunnel webs in holes of earthbanks on roadside and in holes and in moss on granite rock close to a small waterfall in the forest. This species does not have a clear preference for limestone (as Phyxioschema spp. in southern Thailand have): only at Ban Chong Phlie was a female collected from a web in a crack of a limestone bolder. Four females from Ko Libong produced egg sacs in captivity in late August 2005; from one of them spiderlings hatched 22 days later. In captivity – but not in nature – females from Ko Libong and Ko Tarutao camouflaged the white lenticular egg sacs by attaching soil particles to their surface. No limited mating period could be observed. Some males from the northern localities were collected as adults in the field between late June and early December, others collected as immatures matured in captivity during the same period of the year. On Ko Sukon a mature male was collected in late May, and males collected on Ko Tarutao in early January matured in February and between June and November.
In captivity a pair from Ko Tarutao mated in the following manner: The male courted in the web of the female by quivering and tiptoeing. He approached the female directly, abruptly and forcefully pulled her towards him, locked his tibia II spur and megaspines onto her femur II which was bent sideward at a right angle, whilst his legs I bent her legs I and palps far backwards. In this locked position, which lasted for 21 minutes, the male alternately inserted his palpal organs several times. The pair then separated abruptly and the female chased the male away. That female produced a first egg sac exactly one month later and the spiderlings hatched two weeks afterwards. A second egg sac was produced later. Another female (collected gravid) from Ko Tarutao constructed seven egg sacs in a succession. A total of 33 egg sacs were preserved, each containing 5- 17 eggs and early instar spiderlings; eight eggs was the most common count (n = 7).
description: Published as part of Schwendinger, Peter J., Lehmann-Graber, Christina, Hongpadharakiree, Komson & Syuhadah, Nurul, 2020, New euagrid spider species from Thailand and Malaysia, and new localities of Leptothele bencha (Arachnida: Araneae), pp. 423-453 in Revue suisse de Zoologie 127 (2) on pages 428-431, DOI: 10.35929/RSZ.0031, http://zenodo.org/record/5743952