Walckenaeria sinuosa Irfan, Zhang & Peng

Irfan, Muhammad, Zhou, Gu-Chun, Peng, Xian-Jin & Zhang, Zhi-Sheng, 2025, Survey of Linyphiidae spiders (Arachnida: Araneae) from some Oriental Regions of China, Megataxa 15 (1), pp. 1-248 : 210-217

Walckenaeria sinuosa Irfan, Zhang & Peng , sp. n.

(弯àĩe)

Figures 280–282 , 307

Types. Holotype ♂ ( HNU–CQ– IV–1721 ), CHINA, Chongqing, Pengshui Co., Mowei MSS , 29.18643°N, 108.041981°E, 1568 m, 25.VII.2017, M. Irfan & G.C. Zhou leg. Paratypes: 12♀, with same data as for holotype male ( HNU–CQ– IV–1721 ) ; 2♀, Pengshui Co., Mowei MSS , 29.16079°N, 108.03732°E, 26.VII.2017, Irfan M. & G.C. Zhou leg. ( HNU–CQ– IV–1723 ) ; 1♀, Pengshui Co., Mowei MSS , 29.16067°N, 108.03687°E, 1548 m, 23. V.2017, G.C. Zhou e t al. leg. ( HNU–CQ– IV–1702 ).

Etymology. The specific epithet is derived from the Latin adjective “sinuosus” meaning “sinuous” and referring to the embolus sinuous in male palp.

Diagnosis. Walckenaeria sinuosa sp. n. can be distinguished from all other congeners by the dorsal tibial apophysis relatively wider at proximal end, narrowing towards tip, C-shaped, tip with long thick spines; embolus sinuous in male palp ( Figs 280A–D ). Female can be distinguished by the ventral plate of epigyne mid ventrally with rectangular roof followed by arch-shaped sclerotized margin posteriorly, giving rise to a shallow atrium inside; copuplatory openings present mid-ventrally;spermathecae hockey-shaped ( Figs 281A–C ).

Description. Male (holotype, Figs 282A, B ): Total length: 1.73. Carapace 0.92 long, 0.72 wide, brown, cephalic region strongly elevated; cephalic pits present; fovea, cervical and radial grooves distinct. Clypeus 0.23 high. Chelicerae with four promarginal and four retromarginal teeth, anteriorly with large tooth. Sternum longer than wide, brownish grey with microsetae. Eyes: AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.04, ALE 0.07, PME 0.06, PLE 0.06, AME–AME 0.02, PME–PME 0.06, AME–ALE, 0.05, PME–PLE 0.04, AME–PME 0.05, ALE–ALE 0.31, PLE–PLE 0.34, ALE–PLE contiguous. Length of legs: I 2.3 (0.66, 0.79, 0.46, 0.39), II 2.09 (0.65, 0.66, 0.41, 0.37), III 1.74 (0.52, 0.53, 0.38, 0.31), IV 2.28 (0.69, 0.80, 0.42, 0.37). Tibial spine formula: 2-2-1-1. TmI and TmIV present. Opisthosoma 0.97 long, 0.72 wide, oval, grey, with two pairs of sigillae.

Palp ( Figs 280A–D ): Femur unmodified, almost longer than both patella and tibia. Patella as long as proximal part of tibia, mesally slightly curved. Tibia with one retrolateral trichobothria and two apophyses; retrolateral tibial apophysis (RTA) rectangular with round margin; dorsal tibial apophysis (DTA) relatively wider at proximal end, narrowing towards tip, strongly curved, Cshaped, tip with long thick spines; cymbium retrolateral margin with outgrowth extending towards subtegulum, distal end broad; paracymbium (PC) U-shaped; tegulum (T) with long, transparent protegulum (PT), protruding upwardly; distal suprategular apophysis longer than wide, slightly curved. Embolic division: Tailpiece (TP) sclerotized, tongue-shaped, with blunt end, pointing towards the lateral margin of cymbium; embolus (E) sclerotized, sinuous.

Female (one of paratype, Figs 282C, D ): Total length: 1.56. Carapace 0.61 long, 0.54 wide, brown, cephalic region strongly elevated; cephalic pits present; fovea, cervical and radial grooves distinct. Clypeus 0.17 high. Chelicerae with five promarginal and six retromarginal teeth. Sternum longer than wide, yellowish grey with microsetae. Eyes: AER recurved, PER procurved, slightly wider than AER Eye sizes and interdistances: AME 0.03, ALE 0.06, PME 0.05, PLE 0.05, AME–AME 0.02, PME– PME 0.05, AME–ALE, 0.02, PME–PLE 0.02, AME– PME 0.05, ALE–ALE 0.23, PLE–PLE 0.25, ALE–PLE contiguous. Length of legs: I 1.75 (0.50, 0.53, 0.39, 0.33), II 1.57 (0.48, 0.44, 0.36, 0.29), III 1.35 (0.44, 0.41, 0.26, 0.24), IV 1.78 (0.54, 0.63, 0.33, 0.28).Tibial spine formula: 2-2-1-1. TmI and TmIV present. Opisthosoma 1.04 long, 0.74 wide, oval, grey, with two pairs of sigillae.

Epigyne ( Figs 281A–C ): Ventral plate (VP) wider than long, sclerotized, mid ventrally with rectangular roof followed by arch-shaped sclerotized margin posteriorly, giving rise to a shallow atrium inside; copuplatory openings (CO) present mid-ventrally; dorsal plate (DP) partly visible; copulatory ducts (CD) spiral, with one and half coils; spermathecae (S) hockey-shaped, pointing towards each other; fertilization ducts (FD) small, extending mesally.

Distribution. Known only from the type localities (Chongqing, Fig. 307 ).

Figures

FIGURE 280. Walckenaeria sinuosa sp. n., male holotype. A Palp, prolateral view; B Palp, retrolateral view; C Palp, dorsal view; D Palp, ventral view. Abbreviations: DSA—distal suprategular apophysis; DTA—dorsal tibial apophysis; E—embolus; PC—paracymbium; PT—protegulum; R—radix; RTA—retrolateral tibial apophysis; ST—subtegulum; SPT—suprategulum; T— tegulum; TP—tailpiece of radix.

FIGURE 281. Walckenaeria sinuosa sp. n., female paratype. A, B Epigyne, ventral view; C Vulva, dorsal view. Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermatheca; VP—ventral plate.

FIGURE 282. Walckenaeria sinuosa sp. n., male holotype (A, B) and female paratype (C, D). A, C Habitus, dorsal view; B, D Habitus, ventral view.

FIGURE 307. Distribution of Linyphiidae species in Chongqing: 1. Bathyphantes paracymbialis Tanasevitch, 2014; 2. Diplocephalus circularis sp. n.; 3. Frontinella zhui Li & Song, 1993; 4. Gnathonarium dentatum (Wider, 1834); 5. Gongylidioides acuminatus sp. n.; 6. Gongylidioides ensis sp. n.; 7. Gongylidium uncatum sp. n.; 8. Himalaphantes azumiensis (Oi, 1979); 9. Hylyphantes graminicola (Sundevall, 1830); 10. Indophantes wushanensis Irfan, Wang & Zhang, 2023; 11. Lepthyphantes frondeus sp. n.; 12. Wulinggone qizimeiensis sp. n.; 13. Nematogmus ligulatus sp. n.; 14. Nematogmus sanguinolentus (Walckenaer, 1841); 15. Nippononeta alpina (Li & Zhu, 1993); 16. Nippononeta coreana (Paik, 1991); 17. Oia yinae sp. n.; 18. Oilinyphia xinqiaoensis sp. n.; 19. Oilinyphioides triangularis sp. n.; 20. Prosoponoides sinensis (Chen, 1991); 21. Scotinotylus guizhouensis sp. n.; 22. Sinolinyphia henanensis (Hu, Wang & Wang, 1991); 23. Syedra yuelushanensis sp. n.; 24. Ummeliata feminea (Bösenberg & Strand, 1906); 25. Ummeliata insecticeps (Bösenberg & Strand, 1906); 26. Walckenaeria sinuosa sp. n.; 27. Wuliphantes tongluensis (Chen & Song, 1988).