Walckenaeria extenuata 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 : 207-210

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

(ādĩe)

Figures 274–277 , 314 , 315

Types. Holotype ♂ ( HNU–HNDWS–18–05 ), CHINA, Hunan Prov.: Liuyang City, Mudu Vill., Daweishan NFP , 28.43388°N, 114.03376°E, 379 m, 14.I.2018, G.C. Zhou et al. leg. Paratypes: 1♂ 15♀, with same data as for holotype male ( HNU–HNDWS–18–05 ); 1♀, Zhangjiajie City, Wulingyuan District, Suoxiyu Town , Tujia Township , Wenfeng Vill. , 29.35692°N, 110.54491°E, 476 m, 18.IV.2018, D. Li et al. leg. ( HNU–HN– IV–1804 ); 6♀, Hubei Prov.: Xuanen Co., Shadaogou Town, Qizimei Mountain , 29.706342°N, 109.75642°E, 1155 m, 30.IV.2016, W. Liu et al. leg. ( HNU–HB 2016–04–30 ).

Etymology. The specific epithet is derived from the Latin adjective “extenuatus” meaning “fine” and referring to the very fine and thin end of embolus in male palp.

Diagnosis. Walckenaeria extenuata sp. n. can be distinguished from all congeners by the tibia with three apophyses, dorsal tibial apophysis tip with several small teeth and ventrally with larg tooth; prolateral and ventral tibial apophyses thumb-shaped; distal suprategular apophysis tip ear lobe-shaped protruding upward in male palp( Figs274A–D , 275A–C ).Female can be distinguished by the dorsal plate with one pair of protrusions posteriorly with copulatory openings in epigyne; spermathecae oval, encircled by the broad loops of copulatory ducts ( Figs 276A–D ).

Description. Male (holotype, Figs 277A–C ): Total length: 1.55. Carapace 0.71 long, 0.57 wide, brown, with two small, round cephalic lobes behind the PMEs and at the base of PLEs with cephalic pits on each side; fovea, cervical and radial grooves distinct. Clypeus 0.27 high. Chelicerae with three promarginal and five retromarginal teeth. Sternum shield-like, brownish grey with microsetae. Eyes: AER recurved, PER procurved, slightly wider than AER. Eye sizes and interdistances: AME 0.04, ALE 0.06, PME 0.05, PLE 0.05, AME–AME 0.02, PME–PME 0.04, AME–ALE, 0.04, PME–PLE 0.05, AME–PME 0.04, ALE–ALE 0.25, PLE–PLE 0.27, ALE–PLE contiguous. Length of legs: I 2.26 (0.65, 0.79, 0.54, 0.28), II 2.14 (0.62, 0.71, 0.49, 0.32), III 1.69 (0.47, 0.54, 0.43, 0.25), IV 2.17 (0.63, 0.68, 0.55, 0.31). Tibial spine formula: 2-2- 1-1. TmI and TmIV present. Opisthosoma 0.89 long, 0.60 wide, oval, grey, with two pairs of sigillae.

Palp ( Figs 274A–D , 275A–C ): Femur unmodified, almost longer than both patella and tibia. Patella shorter than tibia, ventrally grooved. Tibia with two retrolateral and one dorsal trichobothria and three apophyses; ventral tibial apophysis (VTA) and prolateral tibial apophysis (PTA) thumb-shaped with blunt end; dorsal tibial apophysis (DTA) rectangular longer than wide, curved, tip ventrally with large tooth and tip with several teeth; cymbium unmodified, broad at distal end; paracymbium (PC) C-shaped, distal arm tip knobbed; distal suprategular apophysis (DSA) tip ear lobe-shaped protruding upward. Embolic division: Radix (R) spirally coiled protruding upward; tailpiece (TP) sclerotized, strongly curved with blunt tip, pointing towards the tibia; embolic membrane (EM)running parallel with embolus and distal suprategular apophysis; embolus (E) sclerotized, forming a complete circle, distal part very fine and thin.

Female (one of paratype, Figs 277D, E ): Total length: 1.77. Carapace 0.72 long, 0.56 wide, dark brown, fovea, cervical and radial grooves distinct. Clypeus 0.18 high. Chelicerae with five promarginal and six retromarginal teeth. Sternum shield-like, brownish grey with microsetae. Eyes: AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.05, ALE 0.05, PME 0.05, PLE 0.05, AME–AME 0.01, PME–PME 0.04, AME–ALE, 0.03, PME–PLE 0.05, AME–PME 0.04, ALE–ALE 0.24, PLE–PLE 0.27, ALE–PLE 0.01. Length of legs: I 2.11 (0.62, 0.71, 0.51, 0.27), II 2.06 (0.63, 0.70, 0.48, 0.25), III 1.76 (0.57, 0.52, 0.39, 0.25), IV 2.16 (0.69, 0.67, 0.52, 0.28). Tibial spine formula: 2-2-1-1. TmI and TmIV present. Opisthosoma 1.17 long, 0.85 wide, oval, grey, with two pairs of sigillae.

Epigyne ( Figs 276A–D ): Ventral plate (VP) wider than long; dorsal plate (DP) somewhat round, with pair of tubercles posteriorly with copulatory openings (CO). Spermathecae (S) oval, encircled by the broad loops of copulatory ducts (CD); fertilization ducts (FD) small, extending mesally.

Distribution. Known only from the type localities (Hubei and Hunan Provinces, Figs. 314 , 315 ).

Figures

FIGURE 274. Walckenaeria extenuata 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; Em—embolic membrane; PC—paracymbium; PT—protegulum; PTA—prolateral tibial apophysis; R—radix; ST—subtegulum; SPT—suprategulum; T—tegulum; TP—tailpiece of radix; VTA—ventral tibial apophysis.

FIGURE 275. Walckenaeria extenuata sp. n., male paratype. A Embolic division, ventral view; B Embolic division, prolateral view; C Embolic division, posterior view. Abbreviations: DSA—distal suprategular apophysis; E—embolus; Em—embolic membrane; R—radix; SPT—suprategulum; TP—tailpiece of radix.

FIGURE 276. Walckenaeria extenuata sp. n., female paratype.A, B Epigyne, ventral view; C, D Vulva, dorsal view.Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermatheca; VP—ventral plate.

FIGURE 277. Walckenaeria extenuata sp. n., male holotype (A–C) and female paratype (D, E). A, D Habitus, dorsal view; B Habitus, lateral view; C, E Habitus, ventral view.

FIGURE 315. Distribution of Linyphiidae species in Hunan Prov.: 1. Acanoides cornutus sp. n.; 2. Acanoides ningxiangensis sp. n.; 4. Auriculaiana yongshunensis sp. n.; 5. Baryphyma xiaoxiense sp. n.; 6. Bathyphantes paracymbialis Tanasevitch, 2014; 7. Bathyphantes pseudogracilis sp. n.; 8. Bifurcia ramosa (Li & Zhu, 1987); 9. Bolyphantes arcuatus sp. n; 10. Bolyphantes gladius sp. n.; 11. Capsulia tianmushana (Chen & Song, 1987); 12. Dicristatus cordatus sp. n.; 13. Diplocephalus circularis sp. n.; 14. Drapetisca boletus sp. n.; 15. Drapetisca nanpingensis sp. n.; 16. Drapetisca yuelushanensis sp. n.; 17. Erigone prominens Bösenberg & Strand, 1906; 18. Frontinella zhui Li & Song, 1993; 19. Gnathonarium dentatum (Wider, 1834); 20. Gnathonarium gibberum Oi, 1960; 21. Oedothorax fortis sp. n.; 22. Tapinocyba sulcata sp. n.; 23. Himalaphantes azumiensis (Oi, 1979); 24. Hylyphantes graminicola (Sundevall, 1830); 25. Kaestneria bicultrata Chen & Yin, 2000; 26. Lepthyphantes frondeus sp. n.; 27. Microlinyphia zhejiangensis (Chen, 1991); 3. Microneta acutalis sp. n.; 28. Nematogmus sanguinolentus (Walckenaer, 1841); 29. Nippononeta alpina (Li & Zhu, 1993); 30. Nippononeta coreana (Paik, 1991); 31. Oia baiyunensis sp. n.; 32. Oia lata sp. n.; 33. Oia yinae sp. n.; 34. Oilinyphioides triangularis sp. n.; 35. Paikiniana lurida (Seo, 1991); 36. Parameioneta bilobata Li & Zhu, 1993; 37. Prosoponoides sinensis (Chen, 1991); 38. Ryojius lianghekouensis sp. n.; 39. Ryojius nanyuensis (Chen & Yin, 2000); 40. Scotinotylus longiprojectus sp. n.; 41. Shaanxinus insectus sp. n.; 42. Shaanxinus longiembolus sp. n.; 43. Sinolinyphia henanensis (Hu, Wang & Wang, 1991); 44. Syedra yuelushanensis sp. n.; 45. Tenuiphantes taipingensis sp. n.; 46. Ummeliata feminea (Bösenberg & Strand, 1906); 47. Ummeliata insecticeps (Bösenberg & Strand, 1906); 48. Walckenaeria xingdouensis sp. n.; 49. Walckenaeria extenuata sp. n.; 50. Walckenaeria yanglinensis sp. n.; 51. Wuliphantes tongluensis (Chen & Song, 1988); 52. Yuelushannus diaotangensis sp. n.; 53. Yuelushannus jinyuanensis sp. n.; 54. Yuelushannus wenfengensis sp. n..

FIGURE314.Distributionof LinyphiidaespeciesinHubeiProv.:35.Scotinotyluslongiprojectussp.n.;36.Shaanxinuslongiembolus sp. n.; 37. Sinogone puteus sp. n.; 38. Syedra yuelushanensis sp. n.; 39. Taibaishanus badongensis sp. n.; 40. Ummeliata feminea (Bösenberg & Strand, 1906); 41. Ummeliata insecticeps (Bösenberg & Strand, 1906); 42. Walckenaeria enshiensis sp. n.; 43. Walckenaeria extenuata sp. n.; 44. Walckenaeria xingdouensis sp. n.; 45. Wuliphantes tongluensis (Chen & Song, 1988).