Plistobunus weiguang, Gong & Kury & Zhang, 2021

Gong, Xuyun, Kury, Adriano B. & Zhang, Chao, 2021, Two new species of Plistobunus from China (Opiliones: Laniatores: Epedanidae), Zootaxa 4915 (1), pp. 60-76 : 67-73

Plistobunus weiguang sp. nov.

urn:lsid:zoobank.org:act:AD9780BB-5164-42FD-9999-CDC34104A951

( Figs 30–56 )

Type material. Holotype: male, CHINA: Guangxi Zhuang Autonomous Region, Beiliu City, Minle Town , Da’rongshan National Forest Park , 22°50.731’ N, 110°16.892’ E, Alt 586 m a.s.l., 22 Aug. 2018, Yang Chen leg. (MHBU-Opi- GXBL-18-12) . Paratypes: 1 ³ (MHBU-Opi- GXBL-18-1201) 1 ♀ (MHBU-Opi- GXBL-18-1202), same data as the holotype .

Additional material. CHINA: Guangxi Zhuang Autonomous Region, Fangchenggang, Shi Wan Dashan National Forest Park, 21.9054°, 107.9037°, Alt 276 m a.s.l., 11 July 2016, Alessandro Giupponi, Adriano Kury, Ian Kury & Chao Zhang leg. (material destroyed by the 2018 MNRJ fire) .

Diagnosis. Plistobunus weiguang sp. nov. is distinguishable from congeners by the following characteristics: (1) anterior margin of carapace with a row of five setiferous tubercles on each side ( Fig. 30 ); (2) pedipalpal femur ventrally with 10 setiferous tubercles and with two setiferous tubercles on the prolatero-distal face ( Figs 37–38 ); (3) pedipalpal patella with three long setiferous tubercles at the distal end and one medium sized setiferous tubercle at base ( Figs 37–38 ); (4) ectal surface of basichelicerite with three large tubercles at ectal side ( Figs 39 , 41 ).

Etymology. The species epithet is a noun in apposition after our friend and fellow arachnologist Wei-Guang Lian as a tribute for her work on Chinese harvestmen. ICZN Article 31 deals with species-group names formed from personal names and recommendation 31A explicitly advises against using personal names as nouns in apposition “in order to avoid the appearance that the species-group name is a citation of the authorship of the generic name”. However, as we are using here the given name, rather than the author’s surname, there is no ground for confusion, since we feel that the recommended ICZN mock-1st declension genitive “weiguangae” would not sound euphonic enough.

Description. Male (holotype): habitus as in Figs 30–31, 34 . Coloration: entire body yellow brown. Anterior middle margin of carapace with a black band. Trochanters of legs and pedipalps yellow, other segments of them pale yellowish brown. Basichelicerite with dark reticulations. Cheliceral hand yellow.

Dorsum ( Fig. 30 ). Dorsal scutum trapezoid in shape, widest portion of body at scutal area V. Carapace with five tubercles on both lateral portions of anterior margin. Ocularium oval, wider than long, armed with a long median spine. Area I/II smooth, long in both sides and short in the middle, where it is distorted by carapace outline; area III with a pair of long median spines; area IV with two granules widely separated from each other; the posterior margin of area V with a transversal row of five long tubercles, of which the middle one enlarged into a spine. Free tergites hidden in the scutum, with a transverse conspicuous row of hair-tipped pointed tubercles spread over its entire width.

Venter ( Fig. 31 ). Surface of all coxae tuberculate. Coxa I with a conspicuous median row of five haired tubercles, and on either side of which with a row of small haired tubercles; coxa II with a row of 10 haired tubercles; coxa III–IV with irregularly minute tubercles on the surface. Each free sternite with a transverse row of minute hairtipped granules. Anal plate unarmed, only with some hairs. Spiracles clearly visible.

Chelicera ( Figs 39–42 ). Strongly swollen. Basichelicerite elongated, without marked bulla; the dorsal surface with five hair-tipped tubercles, of which the distal one largest; the ventral surface with some small hair-tipped tubercles. Cheliceral hand considerably swollen, ventrally with three small hair-tipped tubercles; dorsally with nine hair-tipped tubercles. Fingers relatively strong, inner edges toothed as the illustration ( Fig. 40 ).

Pedipalp ( Figs 37–38 ). Relatively long. Coxa ventrally with two hair-tipped tubercles and one granule proximal; dorsally unarmed; ectal view with three conspicuous hair-tipped tubercles and prolateral with two hair-tipped tubercles. Trochanter ventrally with three setiferous tubercles and dorsally with one. Femur elongate, slightly curved; ventrally with a row of 10 setiferous tubercles; on the medial distal side with two setiferous tubercles; dorsally with eight setiferous tubercles. Patella ventro-ectal with one short proximal and one long distal megaspine; medio-distally with two shorter megaspines; dorsally with two conspicuous hair-tipped granules. Tibia with three megaspines mesally; ectally with five megaspines; ventrally with a row of four small megaspines. Tarsus with four megaspines on both sides of ventral surface; ventrally with a row of eight megaspines. Tarsal claw slightly curved, as long as tarsus.

Legs ( Fig. 36 ). Slender and relatively long. Trochanters I–IV smooth. Femora I–II ventrally with a longitudinal row of seven or 15 setiferous tubercles respectively; dorsally smooth; femur III ventrally with eight granules and dorsally with a row minute granules; Femur IV smooth. Patellae, tibiae, metatarsi and tarsi I–IV unarmed. Tarsal articles cylindrical, long and without scopula. Tarsi III–IV with two bare claws. Distitarsus I–II two-jointed. Tarsal formula (I–IV): 7/18/7/6.

Penis ( Figs 48–53 ). 1.45 long. The shaft slender, distended distally. The ventral plate separated again by a median cleft, forming a stereoscopic structure—the pseudocalyx of Kury et al. (2019) or ventral frame of Zhang & Martens (2018), noted as the VF in Fig. 48 . Glans partially sunken into dorsal depressed portion of pars distalis. Stylus sunken into CE and CI. Capsula interna ventrally everted at distal end. Stylus columnar and arising straight from the glans. Spination asymmetrical. Macrosetae D1–D2 closely associated with basal glans, but widely separated from A1–A2 + B1. C1–C3 stunted, closely associated with glans base. Macrosetae E and F separated from the others by a gap. E1–E2 forming a ventral quadrangular figure. F1–F2 more lateral and considerably more proximal than E.

Female ( Figs 32–33, 35 , 43–47 , 54–56 ). In general appearance similar to the male, but smaller than the male. Scutum wider than the male in the posterior margin of area IV. Pedipalp ( Figs 46, 47 ) femur ventrally with a row of seven small setiferous tubercles; dorsally with nine setiferous tubercles; patella with one long tubercle ventrodistally and medio-distally with two long tubercles. Chelicera ( Figs 45 , 54–56 ) smaller, Cheliceral hand with reduced tubercles; basichelicerite dorsally with one large hair-tipped tubercle; ventrally with two minute hair-tipped tubercles; inner edges of finger toothed as illustration ( Fig. 56 ). Femur of leg I with small hair-tipped tubercles.

Ovipositor as illustrated ( Figs 43–44 ). Ventral surface with four setae and dorsal surface with six setae.

Measurements. Male holotype (female paratype). Body 2.70 (2.71) long, 2.23 (2.30) wide at the widest portion, carapace 1.46 (1.11) long, 1.71 (1.55) wide, scutum 2.43 (2.32) long. Ocularium 1.04 (1.00) height, 0.71 (0.62) wide. Pedipalp claw 6.13 (5.82) long. Measurements of pedipalp and legs as in Tables 3–4.

Habitat. The specimens were collected by sieving leaf litter in moist places of the forest.

Distribution. Guangxi Province, China. WWF Ecoregion: South China-Vietnam subtropical evergreen forests (IM0149) ( Figs. 57–60 ).

Figures

FIGURES 30–36. Plistobunus weiguang sp. nov. 30. Male body, dorsal view. 31. Same, ventral view. 32. Female body, dorsal view. 33 Female body, ventral view. 34. Male body, lateral view. 35. Female body, lateral view. 36. Left femur I of male, prolateral view. Scale bars: 1mm (30–35); 0.5mm (36).

FIGURES 37–40. Plistobunus weiguang sp. nov. 37. Left pedipalpus of male, ectal view. 38 Same, medial view. 39 Basichelicerite, male, dorsal view. 40. Left cheliceral fingers, male, frontal view. Scale bars: 1mm.

FIGURES 41–45. Plistobunus weiguang sp. nov. 41. Left chelicera, male, medial view. 42. Same, ectal view. 43. Ovipositor, ventral view. 44. Same, dorsal view. 45. Basichelicerite, female, dorsal view. Scale bars: 0.25mm (43–44,); 1mm (41-42, 45);

FIGURES 46–47. Plistobunus weiguang sp. nov. 46. Left pedipalpus of female, ectal view. 47. Left pedipalpus of female, medial view. Scale bars: 1 mm.

FIGURES 48–53. Plistobunus weiguang sp. nov. 48. Penis, dorsal view. 49. Distal part of penis, lateral view. 50. Distal part of penis (expanded), lateral view. 51. Distal part of penis, dorsal view. 52. Distal part of penis (expanded), dorsal view. 53. Distal part of penis, ventral view. Scale bars: 0.25mm (49–53); 0.5mm (48).

FIGURES 54–56. Plistobunus weiguang sp. nov. 54. Left chelicera, female, medial view. 55. Same, ectal view. 56. Left cheliceral fingers, female, frontal view. Scale bars: 0.25mm (54, 56); 1mm (55).

FIGURES 57–60. Plistobunus weiguang sp. nov., China, Guangxi, Shiwan Dashan: 57. Male in vivo, dorsal view. 58. Same, lateral view. 59. Tropical moist broadleaf forest inhabited by this species. 60. Typical microhabitat of small epedanids.All photographs by AB Kury.