Plistobunus jaegeri, Zhang & Martens, 2020

Zhang, Chao & Martens, Jochen, 2020, A taxonomic study on Epedanidae from Thailand including functional aspects of male genital morphology (Opiliones, Laniatores), ZooKeys 915, pp. 25-58 : 25

Plistobunus jaegeri sp. nov. Figures 32-39 , 40-54 , 55-61 , 62-67

Type material.

Holotype male (SMF-CJM7060): THAILAND: Ubon Ratchathani Province: Khong Chiam District, Pha Taem NP (No.28), 15°23.94'N 105°30.49'E, alt. 185 m, 5 November 2010, S. Dashdamirov leg. Paratype. One female (SMF-CJM7062): THAILAND: Nong Khai Province: Sangkhom District, Tham Tip Waterfall (No. 23), 18°7.57'N 102°11.16'E, alt. 198 m, 3 November 2010, S. Dashdamirov leg.

Diagnosis.

The dorso-distal margin (blue in Fig. 57a ) of ventral plate much higher than the dorso-distal margin (purple in Fig. 57a ) of pars basalis, the ventral and dorsal side of distal margin of pars basalis of penis not in the same level (cf. Fig. 57b ). Dorsal opisthosomal areae II and IV without long spines in male (Figs 32 , 63 ). The pedipalpal femur medio-distally with one seta-tipped tubercle, and the male patella with one short tubercle at base instead of unarmed in female (Figs 38 , 52 ).

Etymology.

The new species is dedicated to Dr. Peter Jäger, Germany, an esteemed arachnologist. He is a co-founder of the Asian Society of Arachnology (ASA) and due to his efforts, arachnology in Asia has taken a large step forward.

Description.

Male (holotype) habitus as in Figs 32 , 40 , 62 , 63 . Coloration (Figs 62 , 63 ): entire body dorsally rusty yellow with brown patches; median area of prosoma with brown reticulations in front of the ocularium; on each side behind ocularium brown outlines; both lateral ridges of the prosomal and opisthosomal scuta with dark brown stripes; opisthosomal areae I-III with light brown outlines; areae IV and V with a dark transverse band; free tergites with three large dark brown blotches; venter concolorous with the dorsum; chelicerae, pedipalps and legs rusty yellow, reticulated with light to dark brown.

Dorsum (Figs 40 , 62 ). Dorsal scutum trapezoid in shape, widest portion of body at area IV, the abdomen broadly rounded posteriorly. Anterior margin of prosoma with six tubercles. Ocularium oval, removed from anterior border of scutum by 0.40 mm, armed with a long median upright spine. The anterior margin of opisthosomal area I strongly bowed and the borders of other areae slightly bowed. Opisthosomal area I with a median pair of seta-tipped tubercles; areae II and III with similar median tubercles in addition to a few smaller ones on each side; areae IV and V and free tergites with a transverse row of seta-tipped tubercles.

Venter (Fig. 64 ). Coxae with tubercular surface. Coxa I with enlarged seta-tipped tubercles. Coxae II-IV with minute seta-tipped tubercles. Genital operculum with a few seta-tipped granules. Free sternites with a row of small seta-tipped tubercles. Spiracles clearly visible.

Chelicerae (Figs 33-37 ). Basichelicerite elongate, its dorsal side centrally with three spines, distal one the longest and proximal one the shortest; the lateral side with a row of four medium-sized spines; on the medial side four seta-tipped tubercles spirally arranged, in addition with a basal protuberance; ventral side with eight seta-tipped tubercles. Cheliceral hand considerably broad, pro-dorsally with some seta-tipped tubercles; three seta-tipped tubercles on the ventral side. Fingers strong, inner edges toothed (Fig. 37 ): moveable finger and fixed finger with five stumpy teeth.

Pedipalps (Figs 38 , 39 ). Coxa dorsally and ventrally each with three seta-tipped tubercles. Trochanter ventrally with three, dorsally with one seta-tipped tubercles. Femur ventrally with a row of nine; dorsally with a row of nine seta-tipped tubercles; medio-distally with one seta-tipped tubercle. Patella ventro-mesally and ventro-ectally each with two seta-tipped tubercles. Tibia ventro-mesally with three and ventro-ectally with four and ventrally with one seta-tipped basal tubercle. Tarsus with four seta-tipped tubercles on ventral side. Tarsal claw curved, longer than tarsus.

Legs (Figs 41-44 ). Trochanters I-IV ventrally with a few small seta-tipped granules. Femora I-IV ventrally with longitudinal row of many seta-tipped tubercles; size on femur I enlarged and on femora II-IV reduced, on femur IV inconspicuous. Patella I ventrally with two seta-tipped granules. Tarsi III and IV with smooth double claws, without scapulae. Distitarsi I and II two-jointed. The remaining leg segments unarmed. Tarsal formula (I-IV): 6(2)/15(2)/6/7.

Penis (Figs 55-61 ). The shaft slender, parallel-sided, enlarged towards glans, distal end broadest. Distal part of truncus, i.e., glans area, almost trapezoid (ventral view, Figs 55 , 56 , 59 ), and dorsally without an indentation on the distal margin (Fig. 56 , cf. Fig. 19 ). Glans partially sunken into dorsally depressed portion of pars distalis of penis, its tip slightly extending the distal margin (blue in Fig. 57a ) of the ventral plate. The distal extension of capsula externa of semi-circular shape (Fig. 60 ). The distal extension of capsula interna fused into a V-shaped structure (ventral view, Fig. 59 ). Stylus columnar, flat distally (lateral view, Fig. 60 ). Spination asymmetrical, in position a single seta D; spination symmetrical, one pair of setae B, two pairs of setae C, E, and F, and three pairs of setae A.

Female (Figs 45-54 , 65-67 ). In general appearance similar to the male. Scutum more widely trapezoid and wider than that of male in the posterior margin. Opisthosomal area II with a median pair of spines, area IV with a median spine (Fig. 66 ). Chelicera smaller and with reduced tubercles, the dorsal surface of basichelicerite centrally with one spine, the ventral surface of cheliceral hand with one seta-tipped tubercle, inner edges of finger toothed as illustrated (Fig. 51 ). Pedipalpal (Fig. 52 ) femur ventrally with a row of six, dorsally with three conspicuous seta-tipped tubercles, medio-distally without any seta-tipped tubercle; patella with three seta-tipped tubercles. The seta-tipped tubercles on femur I (Fig. 46 ), as well as femora II-IV inconspicuous. Tarsal formula (I-IV): 7(2)/18(2)/7/8.

Ovipositor (Figs 53 , 54 ). On ventral side with four and on dorsal side with six setae.

Measurements.

Male holotype (female paratype). Body 2.40 (3.53) long, 1.94 (2.08) wide at the widest portion, scutum1.68 (2.23) long. Ocularium 0.33 (0.32) long, 0.61 (0.56) wide. Proximal chelicerae 1.24 (1.11) long, 0.35 (0.30) wide; second 1.80 (1.50) long, 0.60 (0.42) wide; distal 0.76 (0.76) long, 0.19 (0.16) wide. Pedipalpus claw 0.60 (0.79) long. Penis 0.94 long. Measurements of pedipalpus and legs as in Tables 3 and 4 .

Habitat.

The specimens were collected by hand under stones in forest.

Distribution.

Known only from the type locality, the Pha Taem National Park in the Ubon Ratchathanl Province, Thailand.

Notes. The genus Plistobunus was known by two species restricted to China, i.e., P. rapax Pocock, 1903 (type species, Hong Kong) and P. columnarius Lian et al., 2011 (Hainan Island). The most distinctive characters of these two species are a pair of long dorsal spines on opisthosomal area II and a median long spine on area IV. However, these characters are not conspicuous in the male of P. jaegeri sp. nov. (Figs 32 , 63 ).

Figures

Figures 32 - 39. Plistobunus jaegeri sp. nov., male holotype 32 body, lateral view 33 left chelicera, medial view 34 same, lateral view 35 left basichelicerite, dorsal view 36 left cheliceral hand, frontal view 37 left cheliceral fingers, frontal view 38 left pedipalp, medial view 39 same, lateral view. Scale bars: 1 mm (32 - 36, 38, 39), 0.5 mm (37).

Figures 40 - 54. Plistobunus jaegeri sp. nov. male (Figs 40 - 44, holotype) and female (Figs 45 - 54, paratype) 40, 45 body, dorsal view 41 right leg I, retrolateral view 42 - 44, 46 femur of right legs, retrolateral view 42 leg II 43 leg III 44 leg IV 46 leg I 47 left chelicera, medial view 48 same, lateral view 49 left basichelicerite, dorsal view 50 left cheliceral hand, frontal view 51 left cheliceral fingers, frontal view 52 left pedipalp, medial view 53 ovipositor, ventral view 54 same, dorsal view. Scale bars: 1 mm (40 - 46, 52), 0.5 mm (47 - 51), 0.25 mm (53, 54).

Figures 55 - 61. Plistobunus jaegeri sp. nov., genitalia of male holotype (not included Fig. 57 b) 55 penis, ventral view 56 pars distalis of penis, ventral view 57 a same, lateral view 58 same, dorsal view 57 b pars distalis of penis, lateral view (Plistobunus columnarius Lian et al., 2011) 59 pars distalis of penis (everted), ventral view 60 same, lateral view 61 same, dorsal view. Abbreviations: CE capsula externa CI capsula interna G glans Pb pars basalis Pd pars distalis S stylus VP ventral plate. Scale bars: 0.25 mm.

Figures 62 - 67. Photographs of male (Figs 62 - 64, holotype) and female (Figs 65 - 67, paratype) of Plistobunus jaegeri sp. nov. 62, 65 body and parts of appendages, dorsal view 63, 66 body and parts of appendages, lateral view 64, 67 body and parts of appendages, ventral view. Scale bars: 1 mm.

Figures 18 - 25. Euepedanus dashdamirovi sp. nov., genitalia of male holotype 18 penis, lateral view 19 pars distalis of penis, ventral view (arrow indicates indented distal end) 20 same, lateral view 21 same, dorsal view 22 pars distalis of penis (everted), ventral view 23 same, dorsal view 24 - 25 same, lateral view. Abbreviations: CE capsula externa CI capsula interna DL dorsal lobe G glans Pb pars basalis Pd pars distalis S stylus VP ventral plate VL ventral lobe. Scale bars: 0.5 mm (18), 0.25 mm (19 - 25).