Tetragnatha bimaculata Li & Liu, 2022

Li, Song-lin, Liu, Ping & Peng, Xian-jin, 2022, Three new species of the genus Tetragnatha Latreille, 1804 (Araneae, Tetragnathidae) from China, ZooKeys 1125, pp. 87-101 : 87

Tetragnatha bimaculata Li & Liu sp. nov.

Figs 3 , 4 , 7

Type material.

Holotype ♂: China: Hubei Province, Xuanen County: Shadaogou Township, Yuquan River, 29.7114°N, 109.7278°E, 805 m, 1.V.2016, W. Liu et al. leg. (HNU-HB-IV-1610). Paratypes: 4♂♂ 4♀♀, same data as holotype (HNU-HB-IV-1610); 1♂, Sidaoshui Village, 29.6846°N, 109.5791°E, 602 m, 2.V.2016 (HNU-HB-IV-1611), 6♂♂, Wanzhai Township, Dongping Dam, 30.1470°N, 109.6127°E, 519 m, 4.V.2016 (HNU-HB-IV-1613), W. Liu et al. leg. Hunan Province, Shimen County, Huping Township: 2♀♀, Quanping Village, Zhipeng River, 30.0131°N, 110.5980°E, 611 m, 15.VI.2014 (HPS140615), 2♀♀, Jinbanshan Village, Yanshan Road, 30.0066°N, 110.5653°E, 520 m, 13.VI.2014 (HPS140613), 1♀, Quanping Village, 30.0123°N, 110.5432°E, 935 m, 18.VI.2014 (HPS140618), J.H. Gan et al. leg.

Etymology.

The specific epithet is the combination of the prefix bi - (two) and the Latin adjective maculatus (with spot), referring to the two dark spots on the posterior part of the abdomen.

Diagnosis.

The males of this new species resemble those of T. tanigawai Okuma, 1988 ( Okuma 1988: fig. 3A-G) in the elongate and curved dorsal spur of chelicera, the fang with an outer cusp, and the expanded proximal part of the conductor, but can be distinguished by: (1) the distance between the guide tooth and the second tooth of the upper row of chelicera almost equal to the distance between the second and third teeth of the upper row of chelicera in males of T. bimaculata sp. nov. (Fig. 3D ) (vs. the distance between the guide tooth and the second tooth of the upper row of chelicera> 3 × longer than the distance between the second and third teeth of the upper row of chelicera; fig. 3A in Okuma [1988]); (2) the conductor is ~ 3 × longer than tegulum (Fig. 3I ) with proximal 2/3 expanded (Fig. 3H ) (vs. the conductor is ~ 2 × longer than the tegulum (fig. 3G in Okuma [1988]) with proximal 1/2 part expanded; fig. 3D in Okuma [1988]); (3) the distal portion of conductor is almost rounded (Fig. 3G, H ) (vs. with notch; fig. 3E, G in Okuma [1988]). The females of this new species resemble that of T. esakii Okuma, 1988 ( Zhu et al. 2003: fig. 62A-F) in the shape of epigynal fold, the presence of a pair of spermathecae, and the absence of a central membranous sac in the vulva, but can be distinguished by the spermathecae that are bean-shaped and ~ 2 × longer than wide in T. bimaculata sp. nov. (Fig. 4H ) (vs. almost claviform and ~ 4 × longer than wide; fig. 62F in Zhu et al. [2003]).

Description.

Male (holotype) (Fig. 3A-F ). Total length 5.85. Carapace 1.59 long, 1.20 wide, yellow, fovea and cervical and radial grooves distinct. Eye sizes and interdistances: AME 0.11, ALE 0.08, PME 0.08, PLE 0.09; AME-AME 0.10, AME-ALE 0.17, PME-PME 0.15, PME-PLE 0.15. MO anterior width 0.28, posterior width 0.30, length 0.29. Clypeus 0.16 high. Labium yellow. Sternum pale yellow. Legs yellow, with sparse spines. Leg measurements: I, 20.04 (5.24, 6.43, 6.56, 1.81); II, 14.25 (4.16, 4.69, 4.24, 1.16); III, 7.53 (2.70, 2.21, 1.99, 0.63); IV, 12.23 (4.18, 3.80, 3.49, 0.76). Chelicera: almost as long as carapace; dorsal spur elongated, with pointed and curved tip; AXu present, with blunt tip; upper row with 7 teeth: Gu largest, distance between U2 and Gu almost equal to distance between U2 and U3, U2 - U4 almost equal in size, other teeth decreasing in size gradually; AXl present, thumb-shaped; lower row with 5 teeth: Gl largest, with widened base, other teeth gradually decreasing in size; fang with an outer cusp at base. Abdomen 4.27 long, 0.94 wide, dorsum pale yellow with serried pale spots and single pair of dark spots posteriorly; venter pale yellow, with paler spots on both sides.

Palp (Fig. 3G-L ). Paracymbium with blunt tip, notch inconspicuous, translucent lobe elongate, ~ 1/6 of width of paracymbium, knob with a truncated tip. Tegulum oval, ~ 2 × wider than long. Conductor without fold, proximal 2/3 of conductor expanded dorsally, distal portion twisted and curved towards dorsal side. Embolus completely enveloped by conductor.

Female (paratype HNU-HB-IV-1610) (Fig. 4A-F ). Total length 6.82. Carapace 1.75 long, 1.16 wide. Eye sizes and interdistances: AME 0.10, ALE 0.08, PME 0.09, PLE 0.10; AME-AME 0.12, AME-ALE 0.16, PME-PME 0.14, PME-PLE 0.15. MO anterior width 0.27, posterior width 0.28, length 0.28. Clypeus 0.12 high. Leg measurements: I, 18.40 (4.78, 5.92, 6.07, 1.62); II, 13.39 (3.83, 4.32, 3.98, 1.26); III, 6.89 (2.35, 2.03, 1.87, 0.64); IV, 11.77 (4.14, 3.54, 3.34, 0.75). Chelicera: AXu absent; upper row with 7 teeth: Gu much smaller than U2, U2 largest, other teeth decreasing in size gradually; AXl absent; lower row with 6 teeth: Gl largest, other teeth decreasing in size gradually. Abdomen 5.06 long, 1.7 wide, dark grey, pattern same as in male.

Epigyne (Fig. 4G, H ). Fold slightly longer than wide. Vulva with 1 pair of bean-shaped spermathecae, ~ 2 × longer than wide, and spaced by ~ 5 × width. Central membranous sac absent.

Distribution.

Known only from the type locality (Fig. 7 ).

Figures

Figure 3. Tetragnatha bimaculata sp. nov., holotype ♂ A-C habitus A dorsal view B lateral view C ventral view D-F left chelicera D upper view E inner view F lower view G, K, L conductor and embolus detail H-J left palp H prolateral view I ventral view J retrolateral view. Scale bars: 1 mm (A-C); 0.3 mm (D-J); 0. 1 mm (K, L).

Figure 4. Tetragnatha bimaculata sp. nov., paratype ♀ A-C habitus A dorsal view B lateral view C ventral view D-F left chelicera D upper view E inner view F lower view G, H female genitalia G epigynal fold, ventral view H vulva, dorsal view. Scale bars: 1 mm (A-C); 0.5 mm (D-H).

Figure 7. Collection localities for Tetragnatha bifurcata sp. nov., Tetragnatha bimaculata sp. nov., and Tetragnatha tortilis sp. nov. in China.