Vietnagone denticulata, 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 : 277-283

Vietnagone denticulata sp. nov. (dzḃẮƦ)

Figures 321–324

Types. Holotype ♂, CHINA, Yunnan, Gongshan County, Dulongjiang Township, Mabidang , stone bridge area, 27.76208°N, 98.34567°E, alt. 1400m, 27 October 2004, V. F. Lee leg. ( VFL –04–0006) . Paratypes: 1♂ 1♀, same data as holotype ( VFL –04–0006); 1♂, Tengchong County, Wahe Township , along Longchuan river at Tongjiazhuang Village, 24.89500°N, 98.67508°E, alt. 1201m, 24 May 2005, Charles Griswold leg. ( CGY120 ) .

Etymology. This epithet derives from the Latin adjective “ denticulata ”, meaning “tooth”, referring to embolic division with teeth in male palp.

Diagnosis. This new species resembles Vietnagone rugulosa ( Song & Li, 2010) in having the similar embolus and the spermathecae ellipsoidal ( Figs 321B, C, 323B, C ; Song & Li, 2010, figs 18, 38), but can be distinguished by palpal tibia with 12 teeth in V. denticulata sp. nov. ( Fig. 321B–D), whereas without teeth in V. rugulosa ( Song & Li, 2010, figs 19–22). Posterior margin of ventral plate of epigyne V-shaped in V. denticulata sp. nov. ( Fig. 323B ), whereas relatively broad in V. rugulosa ( Song & Li, 2010, fig. 37).

Description. Male (holotype, Fig. 322A, C ; one of paratypes Fig. 322B ): Total length: 1.93. Carapace 0.91 long, 0.68 wide; cephalic region elevated, dark brown; fovea, cervical and radial grooves distinct. Clypeus 0.18 high. Sternum longer than wide, dark brown,, sparsely covered with microsetae. Labium wider than long. Maxillae long, distal end broad with scopulae. Chelicerae with four promarginal and five retromarginal teeth. Eyes: AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.05, ALE 0.07, PME 0.07, PLE 0.09 AME–AME 0.03, PME–PME 0.07, AME–ALE, 0.02, PME–PLE 0.03, AME–PME 0.05, ALE–ALE 0.29, PLE–PLE 0.32, ALE–PLE contiguous. Length of legs: I 3.45 (0.97, 1.09, 0.81, 0.58), II 3.20 (0.90, 0.99, 0.76, 0.55), III 2.75 (0.78, 0.87, 0.64, 0.46), IV 3.50 (1.01, 1.12, 0.85, 0.52). Leg formula IV-I-II-III. Tm I 0.43 and Tm IV 0.31. Tibial spine formula: 2-2-1-1. Abdomen 0.99 long, 0.71 wide, oval, greenish-grey with irregular patches, ventral side greenish-grey.

Palp ( Fig. 321A–D): Tibia with 12 teeth, two retrolateral and one dorsal trichobothria, distal end broad, with dorsal tibial apophysis; paracymbium baslly rectangular with fine spines, distal arm broad, tip hookshaped; distal suprategular apophysis sclerotized, distal end grooved with two small apophyses; protegulum distinctly developed, with serrated tip. Lamella characteristca longer than wide, posterior part moderately long and wide with blunt end; embolic membrane small, barely visible on unexpanded palp; embolus moderately long and curved.

Female (paratype, Fig. 323A ): Total length: 2.70. Carapace 0.93 long, 0.72 wide; cephalic region slightly elevated, dark brown; fovea, cervical and radial grooves distinct. Clypeus 0.16 high. Sternum longer than wide, dark brown,, sparsely covered with microsetae. Labium wider than long. Maxillae long, distal end broad with scopulae. Chelicerae with four promarginal and five retromarginal teeth. Eyes: AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.05, ALE 0.07, PME 0.09, PLE 0.07, AME–AME 0.03, PME–PME 0.05, AME–ALE, 0.03, PME–PLE 0.03, AME–PME 0.08, ALE–ALE 0.30, PLE–PLE 0.33, ALE–PLE contiguous. Length of legs: I 3.27 (0.93, 1.05, 0.77, 0.52), II 3.09 (0.89, 0.96, 0.72, 0.52), III 2.67 (0.79, 0.82, 0.62, 0.44), IV 3.40 (0.98, 1.09, 0.82, 0.51). Leg formula IV-I-II-III. Tm I 0.42 and Tm IV 0.32. Tibial spine formula: 2-2-1-1. Abdomen 1.77 long, 1.11 wide, oval, dark gray, mid dorsally with a longitudinal light gray band.

Epigyne ( Fig. 323B, C ): Ventral plate sclerotized, posterior margin narrow, V-shaped; dorsal plate partially covered by the ventral plate, posterior margin rectangular; copulatory openings present at the junction of dorsal and ventral plate; Vulva: Copulatory ducts sclerotized, fused at the beginning, V-shaped, forming a loop before entering the spermathecae; spermathecae elliptical; fertilization ducts short, extending mesally.

Distribution. Known only from the type locality ( Fig. 324 ).

Genus Walckenaeria Blackwall, 1833 (ȆƦø)

Figures

FIGURE 322. Vietnagone denticulata sp. nov., male (holotype, A, C, one of paratypes, B): A Habitus, dorsal view B Habitus, lateral view C Habitus, ventral view.

FIGURE 323. Vietnagone denticulata sp. nov., female (one of paratypes). A Habitus, dorsal view B Epigyne, ventral view C Vulva, dorsal view.

FIGURE 324. Distribution of Vietnagone denticulata sp. nov..