Mermessus datangensis, 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 : 166-168

Mermessus datangensis sp. nov. (±MÊẮƦ)

Figures 190–193

Types. Holotype 1♂, CHINA, Yunnan, Tengchong

County, Jietou Township, Datang Village, Daheling Ganjiao, 25.42018°N, 98.40946°E, alt. 1878m, 19 May 2006, Xian-jin Peng, Xin-ping Wang and Peng Hu leg. (Hu060519). Paratypes: 3♂ 4♀, same data as holotype (Hu060519); 1♂, Tengchong County, Jietou Township , Qiaotou Village, 25.45931°N, 98.64114°E, alt. 1652m, 17 May 2006, Chang-min Yin, Jia-fang Hu and Mingwei Yang leg. ( YHY04 ) ; 8♀, 20 km N Liuku, along West Bank of Salween river , Genmazhai, 26.06667ºN, 98.84833ºE, 975m, 21 October 1998, Charles Griswold, D. H. Kavanaugh and Chun-lin Long leg. (98– WB) ; 6♀, Gongshan County, Cikai Township , 52.6 km W of Gongshan on Dulong Valley Road, 27.76712°N, 98.44131°E, alt. 3737m, 5 October 2002, D. H. Kavanaugh and P. E. Marek leg. ( DHK –2002–036) .

Etymology. This epithet derives from the type locality.

Diagnosis. The new species resembles Mermessus fradeorum ( Berland, 1932) in having the similar chelicerae ( Figs 190A–D , 191A–C ; Tanasevitch 2010, figs 12–19) but can be distinguished by the distal arm of paracymbium round in male palp in M. datangensis sp. nov. ( Fig. 190B ), whereas wider than long in M.fradeorum ( Berland, 1932) (Tanasevitch 2010, fig. 13); distal end of protegulum bifurcated in M. datangensis sp. nov. ( Fig. 190D ), whereas somewhat rectangular in M. fradeorum ( Berland, 1932) (Tanasevitch 2010, fig. 13); the ventral plate of epigyne with a small projection medially in M. datangensis sp. nov. ( Fig. 191B ), whereas projection absent and ventral plate with a deep depression medially in M. fradeorum ( Berland, 1932) (Tanasevitch 2010, fig. 18); copulatory ducts arc-shaped in M. datangensis sp. nov. ( Fig. 191B ), whereas straight in M. fradeorum ( Berland, 1932) (Tanasevitch 2010, fig. 18); distance between the copulatory ducts more than the diameter of spermathecae in M. datangensis sp. nov. ( Fig. 191B ), whereas about half of the diameter in M. fradeorum ( Berland, 1932) (Tanasevitch 2010, fig. 18).

Description. Male (holotype, Fig. 192A, B , one of paratypes Fig. 192C, F ): Total length: 3.04. Carapace 1.35 long, 1.10 wide; cephalic region slightly elevated, brown; fovea, cervical and radial grooves distinct; cephalic pits absent. Clypeus 0.23 high. Sternum longer than wide, greenish-gray, sparsely covered with microsetae. Labium longer than wide. Maxillae long, distal end broad with scopulae. Chelicerae with five promarginal and four retromarginal teeth, dorsally with a row of seven teeth ( Fig. 92C, F ). Eyes: AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.07, ALE 0.06, PME 0.07, PLE 0.07, AME–AME 0.03, AME–ALE, 0.05, PME–PME 0.06, PME–PLE 0.05, AME–PME 0.07, ALE–ALE 0.42, PLE–PLE 0.45, ALE– PLE contiguous. Length of legs: I 3.84 (1.03, 1.32, 0.92, 0.57), II 3.51 (0.97, 1.19, 0.87, 0.48), III 3.02 (1.02, 0.88, 0.69, 0.43), IV 4 (1.09, 1.39, 1.02, 0.50). Leg formula IVI-II-III. Tm I 0.59 and Tm IV 0.54. Tibial spine formula: 2-2-1-1. Abdomen 1.54 long, 0.93 wide, oval, dusky gray, mid dorsally with distinct black longitudinal band followed by five cheverons extending posteriorly, ventral side greenish-gray.

Palp ( Fig. 190A–D ): Patella almost as long as tibia, ventrally and dorsally with small projection; tibia conic, with two reterolateral and one dorsal trichobothria; reterolateral tibial apophysis almost triangular, with pointed end; paracymbium sclerotized, J-shaped, distal arm with hook-shaped tip, ventral surface with spines; tegulum with broad protegulum, distal end bifurcated; distal surategular apophysis relatively broad, distal end slightly grooved; embolic division with few small projection; embolus small, invisible on unexpanded palp.

Female (one of paratypes, Fig. 192D, E ): Total length: 2.65. Carapace 1.22 long, 0.91 wide, brown, mid dorsally slightly elevated; fovea, cervical and radial grooves distinct. Clypeus 0.16 high. Sternum wider than long, brown, sparsely covered with microsetae. Labium wider than long. Maxillae long, distal end broad with scopulae. Chelicerae with five promarginal and four retromarginal teeth. Eye region narrow, AER recurved, PER slightly procurved, slightly wider than AER. Eye sizes and interdistances: AME 0.06, ALE 0.06, PME 0.07, PLE 0.06, AME–AME 0.04, PME–PME 0.06, AME–ALE, 0.06, PME–PLE 0.06, AME–PME 0.06, ALE–ALE 36, PLE–PLE 0.39, ALE–PLE contiguous. Length of legs: I 3.67 (1.02, 1.25, 0.89, 0.51), II 3.31 (0.97, 1.06, 0.82, 0.46), III 2.66 (0.76, 0.87, 0.68, 0.35), IV 3.63 (0.93, 1.31, 0.95, 0.44). Leg formula I-IV-II-III. Tm I 0.46 and Tm IV 0.39. Tibial spine formula: 2-2-1-1. Abdomen 1.30 long, 1.05 wide, all other characteristics same as in male except darker in color.

Epigyne ( Fig. 191A–C ): Ventral plate wider than long, posterior margin completely covered with a strongly sclerotized black covering,posterior end mid ventrally with a small projection and depression containing copulatory opening; dorsal plate trapezoid, posterior margin relatively sclerotized than anterior. Vulva: Copulatory ducts arc-shaped, slightly curved before entering the spermathecae; spermathecae oval, separated by a minimal distance, present dorso-anteriorly; fertilization ducts long extending mesally.

Distribution. Known only from the type locality ( Fig. 193 ).

Genus Microlinyphia Gerhardt, 1928 (ḿƉƦø)

Figures

FIGURE 92. Erigone prominens B̂senberg & Strand, 1906. A, B Epigyne, ventral view C Vulva, dorsal view.

FIGURE 190. Mermessus datangensis sp. nov. male palp of holotype. A prolateral view B retrolateral view C dorsal view D ventral view.

FIGURE 191. Mermessus datangensis sp. nov. female (one of paratypes) epigyne. A, B Epigyne, ventral view C Vulva, dorsal view.

FIGURE 192. Mermessus datangensis sp. nov., male (holotype, A, B), male (one of paratypes, C, F) and female (one of paratypes, D, E). A, D Habitus, dorsal view B, E Habitus, ventral view C Habitus, frontal view F Chelicerae, retrolateral view.

FIGURE 193. Distribution of Mermessus datangensis sp. nov..