Stemonyphantes bifurcatus, Irfan & Zhang & Peng, 2022

Irfan, Muhammad, Zhang, Zhi-Sheng & Peng, Xian-Jin, 2022, Survey of Linyphiidae (Arachnida: Araneae) spiders from Yunnan, China, Megataxa 8 (1), pp. 1-292 : 263-267

Stemonyphantes bifurcatus sp. nov. (ĀZƦ)

Figures 298–301

Types. Holotype ♂, CHINA, Yunnan, Gongshan to Binzhongluo , 27.44348°N, 98.39525°E, alt. 1500–1550m, 7 April to 7 June 2000, Heng-mei Yan, D. H. Kavanaugh, Charles Griswold, Hong-bin Liang, Darrell Ubick & Dazhi Dong leg. (00–GB) . Paratypes: 2♀, same data as holotype male (00–GB) .

Etymology. This epithet derives from the Latin adjective “ bifurcatus ”, meaning “bifurcate”, referring to the bifurcated tip of the anterior radical process in male palp.

Diagnosis. The new species belongs to the Stemonyphantes lineatus -group and can be distinguished from all other congeners by the anterior tegular apophysis notched; radix longer about five times longer than wide, anterior radical apophysis bifurcated ( Fig. 298A, B, D ), epigyne with four spirally coiled grooves ( Fig. 299A– C ).

Description. Male (holotype, Fig. 300A, B ): Total length: 3.27. Carapace: 1.62 long, 1.29 wide, yellowish brown; cephalic region slightly elevated, outline concave; fovea, cervical and radial grooves distinct. Clypeus 0.36 high. Sternum longer than wide, cordiform. Labium wider than long. Maxillae long, distal end broad with scopulae. Chelicerae with three promarginal and four retromarginal teeth. Eye region narrow, AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.07, ALE 0.11, PME 0.09, PLE 0.10, AME–AME 0.05, PME–PME 0.05, AME–ALE, 0.06, PME–PLE 0.08, AME–PME 0.08, ALE–ALE 0.48, PLE–PLE 0.51, ALE–PLE contiguous. Length of legs: I 7.23 (1.97, 2.32, 2.04, 0.99), II 6.32 (1.67, 2.05, 1.54, 1.06), III 5.61 (1.52, 1.58, 1.35, 0.81), IV 6.8 (1.79, 2.06, 1.88, 1.07). Leg formula I-IV-II-III. Tm I 0.69 and Tm IV 0.51. Tibial spine formula: 2-2-2-2. Abdomen 1.65 long, 1.25 wide, oval, gray with greenish-grey white patches; ventral side greenish-grey with white patches.

Palp ( Fig. 298A–D ): Patella slightly shorter than tibia, curved, dorsally with a long thick spine; tibia longer than wide, with ventro-apical long spines; two retrolateral and one dorsal trichobothria. Cymbium with a posteriodorsal broad outgrowth. Paracymbium Jshaped, sparsely covered with microsetae on proximal part. Anterior tegular apophysis gradually narrow, distal end with notched tip. Embolic division: radix longer than wide, anterior radical process bifurcated. Embolus long and thin.

Female (one of paratypes, Fig.300C, D ). Total length: 3.66. Carapace: 1.33 long, 1.22 wide, yellowish brown; cephalic region slightly elevated, outline concave; fovea, cervical and radial grooves distinct. Clypeus 0.31 high. Sternum longer than wide, cordiform. Labium wider than long. Maxillae long, distal end broad with scopulae. Chelicerae with four promarginal and four retromarginal teeth. Eye region narrow, AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.08, ALE 0.10, PME 0.09, PLE 0.10, AME–AME 0.05, PME–PME 0.07, AME–ALE, 0.06, PME–PLE 0.09, AME–PME 0.08, ALE–ALE 0.48, PLE–PLE 0.53, ALE–PLE contiguous. Length of legs: I 6.57 (1.82, 2.09, 1.61, 1.05), II 5.85 (1.67, 1.85, 1.40, 0.93), III 4.8 (1.44, 1.48, 1.17, 0.71), IV 6.27 (1.78, 2.01, 1.51, 0.97). Leg formula I-IV-II-III. Tm I 0.64 and Tm IV 0.53. Tibial spine formula: 2-2-2-2. Abdomen 2.33 long, 1.75 wide, oval, gray with greenish-grey white patches; ventral side greenish-grey with white patches.

Epigyne ( Fig. 299A–C ): With four spirally coiled grooves ending into spermathecae.

Distribution. Known only from the type locality ( Fig. 301 ).

Genus Taibaishanus Tanasevitch, 2006 (ẊƠƜƦø)

Figures

FIGURE 298. Stemonyphantes bifurcatus sp. nov. male palp of holotype. A prolateral view B retrolateral view C dorsal view D ventral view.

FIGURE 299. Stemonyphantes bifurcatus sp. nov. female (one of paratypes). A, B Epigyne, ventral view C Vulva, dorsal view.

FIGURE 300. Stemonyphantes bifurcatus sp. nov., male (holotype, A, B) and female (one of paratypes, C, D). A, C Habitus, dorsal view B, D Habitus, ventral view.

FIGURE 301. Distribution of Stemonyphantes bifurcatus sp. nov.