Bifurcia luding, Yang & Li & Yao, 2024

Yang, Lan, Li, Shuqiang & Yao, Zhiyuan, 2024, Five new species of the spider genus Bifurcia Saaristo, Tu & Li, 2006 (Araneae, Linyphiidae) from Sichuan, China, Zoosystematics and Evolution 100 (2), pp. 705-720 : 705-720

Bifurcia luding sp. nov.

Figs 7 , 8 , 9 , 16 C, F

Type material.

Holotype ♂ ( IZCAS - Ar 44930 ) and paratype 1 ♀ ( IZCAS - Ar 44931 ), Luding County (29 ° 51.60 ' N, 102 ° 2.83 ' E, 2936 m elev.), Garze Tibetan Autonomous Prefecture, Sichuan, China, 20 / 07 / 2004, Lihong Tu leg.

Etymology.

The specific name refers to the type locality; noun in apposition.

Diagnosis.

The new species can be easily distinguished from other congeners by having embolus apex ( AX) that is curved and distally pointed (Fig. 16 C vs. angular, column-shaped, distally blunt, Fig. 16 A, B, G, H , Saaristo et al. 2006: figs 4, 12), by embolus thumb (TH) membranous (Figs 7 C , 16 C vs. sclerotized, Figs 2 C , 5 C , 13 C , 16 A, B, G, H ), by lamellar extension of pseudolamella ( LE) with flower-shaped distal end (Figs 7 C , 16 C vs. lacking LE or LE ribbon-shaped, Figs 2 C , 5 C , 10 C , 13 C , 16 A, B, G, H , Saaristo et al. 2006: figs 4, 12), and by basal part of scape ( BS) shield-shaped (Fig. 8 A vs. T-shaped, Figs 3 A , 11 A , 14 A , Saaristo et al. 2006: figs 6, 14).

Description.

Male (holotype). Total length: 2.23, carapace 1.10 long, 0.90 wide, abdomen 1.12 long, 0.74 wide. Eye inter-distances and diameters: AME 0.06, AME-AME 0.02, ALE 0.07, AME-ALE 0.06, PME 0.08, PME-PME 0.05, PLE 0.07, and PME-PLE 0.06. Sternum 0.50 long, 0.48 wide. Clypeus 0.11 high. Chelicerae promargin with 4 teeth, retromargin with 4 teeth. Length of legs: I 7.57 (1.98, 0.33, 1.96, 2.00, 1.30), II 6.78 (1.90, 0.32, 1.70, 1.74, 1.12), III 4.78 (1.38, 0.30, 1.10, 1.24, 0.76), IV 6.28 (1.84, 0.32, 1.58, 1.62, 0.92). Leg formula: I-II-IV-III. TmI 0.16, TmIV absent. Tibial spine formula: 2-2 - 2 - 2. Carapace yellowish. Sternum dark brown. Abdomen with greenish gray dorsal spots (Fig. 9 A, B ).

Palp (Fig. 7 ). Patella with long dorsal bristle. Tibia unmodified. Cymbium with hook-shaped proximal apophysis ( PCA) pointing retrolaterally. Paracymbium (P) bifurcate with three branches: S-shaped branch, finger-shaped branch and lower branch. Pit hook ( PH) on stout distal part of suprategulum ( SPT) extremely reduced to small outgrowth. Embolic division (Fig. 16 C, F ): anterior part of radix ( APR) hook-shaped; sperm duct inside the radix ( R) inconspicuous with Fickert’s gland ( FG); pseudolamella ( PL) strongly sclerotized; and lamellar extension ( LE) slightly sclerotized with flower-shaped distal end. Anterior terminal apophysis ( ATA) longer than wide; median terminal apophysis ( MTA) membranous with serrated margin; posterior terminal apophysis ( PTA) small and semicircle. Embolus (E) with conical embolus proper ( EP), indistinct thumb (TH), and hooked apex ( AX). Median membrane ( MM) fan-shaped and small chitinized basal part of median membrane ( CPM).

Female (paratype). Total length: 2.53, carapace 0.96 long, 0.84 wide, abdomen 1.66 long, 1.16 wide. Eye inter-distances and diameters: AME 0.06, AME-AME 0.02, ALE 0.09, AME-ALE 0.06, PME 0.09, PME-PME 0.06, PLE 0.07, and PME-PLE 0.06. Sternum 0.66 long, 0.56 wide. Clypeus 0.09 high. Chelicerae promargin with 3 teeth, retromargin with 5 teeth. Length of legs: I 7.01 (1.82, 0.36, 1.92, 1.80, 1.11), II 6.27 (1.74, 0.32, 1.63, 1.56, 1.02), III 4.62 (1.42, 0.28, 1.14, 1.10, 0.68), IV 5.90 (1.78, 0.30, 1.50, 1.46, 0.86). Leg formula: I-II-IV-III. TmI 0.16, TmIV absent. Tibial spine formula: 2-2 - 2 - 2. Coloration generally as in male (Fig. 9 C, D ).

Epigyne (Fig. 8 ). Basal part of scape ( BS) shield-shaped. Both sides of posterior median plate ( PMP) developed well. Distal part of scape ( DPS) forming an incomplete circle with basal part of scape. Spermathecae (S) nearly elliptic.

Distribution.

China (Sichuan, type locality; Fig. 1 ).

Figures

Figure 1. Distribution of the new Bifurcia species from Sichuan, China: 1. B. kangding sp. nov.; 2. B. labahe sp. nov.; 3. B. luding sp. nov.; 4. B. shuangqiao sp. nov.; 5. B. xiaojin sp. nov.

Figure 2. Bifurcia kangding sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A – D).

Figure 3. Bifurcia kangding sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A – C).

Figure 5. Bifurcia labahe sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A – D).

Figure 7. Bifurcia luding sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A – D).

Figure 8. Bifurcia luding sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A – C).

Figure 9. Bifurcia luding sp. nov., holotype male (A, B) and paratype female (C, D) habitus: A, C. Dorsal view; B, D. Ventral view. Scale bars: 0.50 mm (A – D).

Figure 10. Bifurcia shuangqiao sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A – D).

Figure 11. Bifurcia shuangqiao sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A – C).

Figure 13. Bifurcia xiaojin sp. nov., holotype male palp: A. Prolateral view; B. Retrolateral view; C. Ventral view; D. Dorsal view. Scale bars: 0.10 mm (A – D).

Figure 14. Bifurcia xiaojin sp. nov., paratype female epigyne: A. Ventral view; B. Lateral view; C. Dorsal view. Scale bar: 0.10 mm (A – C).

Figure 16. Bifurcia spp., embolic division: A, D. B. kangding sp. nov.; B, E. B. labahe sp. nov.; C, F. B. luding sp. nov.; G, I. B. shuangqiao sp. nov.; H, J. B. xiaojin sp. nov.; A – C, G, H. Prolateral view; D – F, I, J. Retrolateral view. Scale bars: 0.10 mm (A – J).