Sesieutes borneensis, Deeleman-Reinhold, Christa, 2001

Deeleman-Reinhold, Christa, 2001, Forest Spiders of South East Asia With a revision of the sac and ground spiders (Araneae: Clubionidae, Corinnidae, Liocranidae, Gnaphosidae, Prodidomidae and Trochanteriidae)., Forest Spiders of South East Asia With a revision of the sac and ground spiders- Family Liocranidae, Leiden, Netherlands: Brill Leiden; Boston; Köln, pp. 400-505 : 454-455

publication ID 10.5281/zenodo.814704


persistent identifier

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scientific name

Sesieutes borneensis

sp. nov.

Sesieutes borneensis View in CoL sp. n. ( figs 738 View Figs 734 - 736 , 749-752 View Figs 745 - 752 , map 38 View Map 38 )

Type locality. — N Borneo, C Kalimantan, 2°2'S 113°40'E. GoogleMaps

Type material.— Holotype ♂ from the type locality, “ Kaharian”, primary peat swamp forest   GoogleMaps , leaf litter, 2-16.ix. 1985, S. Djojosudmarmo; paratypes: 2 ♂, 2 ♀, same data GoogleMaps .

Other material. — Sarawak, 1 ♂, Kuching, Matang (Mt. Serapi), primary forest , 120 m, very wet leaf litter, 12.i.1984, P. R. and C. L. Deeleman , with 2 ♀ of another, undescribed Sesieutes species; Sabah, Nat. Park Kinabalu , 1 ♂,1 subad. ♀, 1550 m, with ♂ ♀ of S. minor , 23-28.vii.1980, P.R. and C.L. Deeleman; Nat. Park Kinabalu at Poring Hot Springs , 600 m, 1 ♀ walking on the ground, 12.iv.1998, C.L. Deeleman ; Indonesia, N Sulawesi, Dumoga Bone National Park , between Barney’s subcamp and Hogg’s back (400 m), 1 ♂ ( KBIN SulO 17 ), pitfall trap, 10-24.x.1985, R. Bosmans .

Diagnosis.— This species is separated from lucens , scrobiculatus and nitens by the carapace sides covered with nodules, nodules becoming more flattened or obsolete in the middle. The AME are 3/2 larger than ALE, the PME are equal to PLE. The male palp is distinguishable from that in lucens , scrobiculatus and nitens by the conical shape of the proximal tibial apophysis and the tegulum more or less triangular. It is distinct from scrobiculatus and nitens by the distal tibial apophysis which is straight near the base, the onset of the curved part near the apex. The epigynal openings are situated laterally, the spermathecae are much elongated, minor also has a triangular tegulum and a similar vulval structure, but in the male of that species the palpal tibial apophysis is single and quite differently shaped. In borneensis the openings of the vulva are shifted backward and the spermathecae are elongated. Furthermore, the spine pattern is unlike minor . S. borneensis resembles bulbosus closely, for differences see there.

Description.— MALE, holotype. Total length 4.30 mm. Carapace length 2.00 mm, width 1.45 mm, height at coxae II 0.50 mm, head width 0.80 mm, width eye group 0.50 mm; abdomen 1.90 mm long, 1.00 mm wide. Leg lengths: leg I 5.60 mm (1.55-2.00-1.20-0.85), leg II 4.75 mm (1.35-1.65-1.00-0.75), leg III 4.40 mm (1.20-1.40-1.05-0.75), leg IV 6.50 mm (1.70-2.00-1.80-1.00), palp 0.75-0.25- 0.25-0.80 mm. Carapace, sternum and mouthparts dark reddish brown. Carapace covered with nodules, arranged in radiating rows, largest nodules in the periphery. Legs pale brown, femora and tibiae dark, with contrasting light tip, particularly in leg I and IV. Abdomen dark reddish grey with two vague slightly lighter transverse bands, the second divided in the middle and with a dark central dot, posterior to this may appear a few lighter chevrons; ventral side white, uncovered area around spinnerets dark grey, d AME = 11/2 d ALE, anterior eyes equal and close together, PER faintly procurved, posterior eyes about equidistant, half the diameter of AME, separated by their d. Clypeus equal to 1 eye diameter. Leg spination: femur I with 0-1 pl, femur IV with l-0d, tibia I with 7 ventral pairs, tibia II with 6 pairs of ventral spines, tibia III with lv or 1-1v, 1pl, tibia IV with 2v or 2-2v, 1rl, metatarsi I and II with 4 pairs, metatarsus III 2v, 1 rl, metatarsus IV with 2-2v or 1-1v and 1pl and 1rl. Dorsal scutum covering all of abdomen, ventral scutum with three grooves in collar. Palp ( figs 738 View Figs 734 - 736 , 749-750 View Figs 745 - 752 ): femur not modified, tibial apophysis as in fig. 750 View Figs 745 - 752 , tegulum roundish-triangular, relatively short, embolus long, encircling whole dorsal side of tegulum.

FEMALE, paratype. Total length 5.00 mm. Carapace length 2.35 mm, width 1.65 mm, head width 1.00 mm. width eye group 0.75 mm; abdomen 2.60 mm long, 1.50 mm wide, epigyne 0.55 mm wide, 0.70 mm long. Leg lengths: leg I 6.55 mm (1.80-2.40-1.45-0.90) leg II 5.70 mm (1.60-2.05-1.20-0.85), leg III 5.00 mm (1.35-1.60-1.15-0.90), leg IV 7.55 mm (1.95-2.35-2.05-1.20), palp 0.85-0.32-0.45- 0.80 mm. Carapace, eyes, mouthparts, sternum as in the male, legs with only femora darker than other segments; abdomen covered with 2/3 scutum, dorsal pattern not so vague, posterior end of abdomen dorsally dark grey with white dot in front of spinnerets. Epigyne longer than wide, openings posterolaterally ( fig. 751 View Figs 745 - 752 ), vulva fig. 752 View Figs 745 - 752 .

Variability.— The male from Mt. Kinabalu (1550 m) has a somewhat reduced dorsal scutum and the PME are slightly smaller than PLE. The male from Matang does not show any pattern on the dorsal scutum; in the non-adult specimen from Mt. Kinabalu the dorsal pattern is strongly expressed. Total length of other male paratypes is 4.20 mm and 4.30 mm, other female paratype 5.50 mm, male Kinabalu 4.90 mm, male Matang 4.80 mm.

A specimen from Brunei is very similar, the duct-coils in the vulva extend much further posteriorly, the distal palpal apophysis in the male is less curved.

Note.— The male specimen in Matang was found together with 2 females of another species with smooth shiny carapace, reduced PME, straight truncation of the PMS and females the openings to the vulva are located centrally.

Distribution.— Lowland of C Borneo and N Sulawesi; by absence of females in Kinabalu Head Quarters, W Sarawak (Matang) and N Sulawesi the conspecifity of the material from these localities cannot be confirmed. This is a disjunct range with a gap in eastern Borneo; in this gap occurs Sesieutes bulbosus .

When writing this, (1998), the peat swamp forests of Kaharian and Tumbang Tahai have been destroyed; they have been replaced by oil palm plantations.

Etymology. — After the island which is home to this species.


Belgium, Brussels, Institut Royal des Sciences Naturelles de Belgique













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