Pholcus bessus Zhu & Gong, 1991

Zhang, Feng & Zhu, Ming-Sheng, 2009, A review of the genus Pholcus (Araneae: Pholcidae) from China, Zootaxa 2037 (1), pp. 1-114 : 15

Pholcus bessus Zhu & Gong, 1991

( Fig. 3 )

Pholcus bessus Zhu & Gong 1991: 20 , f. 3A–G. Song, Zhu & Chen 1999: 57, f. 23D–G. Song, Zhu & Chen 2001: 74, f. 31A–G.

Diagnosis. This species resembles P. crypticolens , P. manueli and P. spilis , probably near relatives, in the shape of the palpal bulb, all with broad, almost triangular appendices; all femora of male palps with a dorsal projection retrolaterally; all epigyna with large pore plates. P. bessus can be distinguished from P. crypticolens and P. spilis by the shape of tip of the procursus ( Figs. 3F–G ), by the broad V-shape of the anterior sclerotized arch of epigynum ( Fig. 3B ), and by the carapace with butterfly-shaped central marks ( Fig. 3C ), from P. manueli by the shape of tip of the procursus and the larger appendix of the bulb ( Figs. 3F–G ).

Redescription. Male (holotype), total length 3.6: cephalothorax 1.1 long, 1.3 wide; abdomen 2.5 long, 1.3 wide. Leg I: 36.1 (9.2+0.6+9.4+14.6+2.3), tibia II: 6.5, tibia III: 4.2, tibia IV: 5.8; Tibia I L/D: 72. Prosoma shape as in Fig. 3C . Carapace short, broad and almost circular, ochre, with brown butterfly-shaped marks broadly connecting to ocular area. Cephalic region clothed with short, erect and black hairs, without brown marks centrally; ocular area light yellow. Clypeus 0.40, unmodified, slightly ochre, without yellow marks. Distance AME–AME 0.03. Diameter AME 0.07, ALE 0.15, PME 0.15, PLE 0.15. Chelicerae as in Fig. 3E , with pair of black serrated apophyses distally, pair of unsclerotized thumb-shaped apophyses proximolaterally and pair of small unsclerotized rounded apophyses proximocentrally. Labium light yellow. Sternum longer than wide, yellow, with three pairs of gray patches laterally and a mark centrally. Femora, patellae and tibiae ochre, with dark rings, metatarsi and tarsi brown. Abdomen cylindrical, pale ochre, dorsum with numerous blackish marks. Venter pale brown. Palps as in Figs. 3F and 3G , bulb with a curved uncus and a triangular appendix, femur with a small projection retrolaterally.

Variation. Tibia I in two other males: 8.8, 9.1. Body color in holotype deeper than in other males and females.

Female: in general very similar to male. Total body length 4.3–4.4. Female (‘allotype’), total length 4.4: cephalothorax 1.2 long, 1.3 wide; abdomen 3.2 long, 2.6 wide. Tibia I 5.6 (in other female missing). Epigynum roughly rectangular as in Fig. 3A , with a knob-shaped apophysis on the top. Dorsal view as in Fig. 3B , with a broad V-shaped sclerotized arch anteriorly and a pair of large oval pore plates.

Distribution. Known from type locality and one neighboring locality in Mt. Zhangshiyan, Zanhuang County, Hebei Province, China.

Material examined. CHINA: Hebei: Jingxing County, Mt. Cangyan , August 26, 1985, leg. M. S. Zhu, male holotype, female ‘allotype’ , 2♂, 1♀ paratypes ( MHBU); Zanhuang County, Mt. Zhangshiyan , June 15, 1998, leg. F. Zhang , 1♀ assigned tentatively ( MHBU) .

Figures

FIGURE 3. Pholcus bessus Zhu & Gong, 1991 (illustrations modified from Zhu & Gong 1991). A. epigynum, ventral view. B. same, dorsal view. C. male prosoma, dorsal view. D. trochanter of male left palp, retrolaterodorsal view. E. male left chelicera, frontal view. F. left palp, prolateral view. G. same, retrolateral view. Scale lines: 1.0mm (C), 0.5mm (A, B, E–G), 0.2mm (D).