Baiyuerius tamdao Zhao, B. Li & S. Li, 2023

Zhao, Zhe, Li, Bing, Zhang, Xiaoqing, Ballarin, Francesco, Pham, Dinh-Sac & Li, Shuqiang, 2023, Baiyuerius gen. nov., a new genus of Coelotinae (Araneae, Agelenidae) spiders from China and Vietnam, ZooKeys 1165, pp. 43-60 : 43

Baiyuerius tamdao Zhao, B. Li & S. Li sp. nov.

Figs 4 , 8

Type material.

Holotype ♀ (IZCAS-Ar44393) (ZZ495): Vietnam: Vinh Phuc Province: Tam Dao National Park (field), 21.4720°N, 105.6364°E, elevation: 1023 m, 31.X.2012, H. Zhao and Z. Chen leg.

Etymology.

The new species is named after the type locality, the Tam Dao National Park; noun in apposition.

Diagnosis.

Baiyuerius tamdao sp. nov. can be distinguished from the other congeners of this genus as follows: 1) swell of epigyne as twice as atrium, spherical and uniformly yellow (Fig. 4A ) vs. as the same size as atrium in others, long-eggplant-shaped, with brown margin in others (Figs 2A , 7A ); 2) posterior epigynal sclerite near trapezoidal (Fig. 4A ) vs. pentagonal (in B. daxi ) or near rhomboid (in B. zuojiang ) (Figs 2A , 7A ); and 3) copulatory ducts extending anteriorly, anterior overlapping to each other (Fig. 4B ) vs. extending along the sclerotic margins of the atrium and separated anteriorly in others (Figs 2B , 7B ).

Description.

Female (holotype) (Fig. 4C-E ). Total length 10.94. Carapace 5.86 long, 3.61 wide. Abdomen 5.08 long, 3.34 wide. Eye sizes and interdistances: AME: 0.11, ALE: 0.23, PME: 0.22, PLE: 0.26; AME-AME: 0.05; AME-ALE: 0.14; AME-PME: 0.09; ALE-PLE: 0.02; PME-PME: 0.06; PME-PLE: 0.23. Leg measurements: I: 15.25 (0.96, 0.42, 3.81, 1.69, 3.42, 2.80, 2.15); II: 13.63 (0.83, 0.36, 3.74, 1.60, 2.72, 2.41, 1.97); III: 11.18 (0.79, 0.32, 3.12, 1.53, 2.03, 1.96, 1.43); IV: 15.47 (0.98, 0.38, 4.31, 1.83, 3.19, 2.93, 1.85). Leg formula 4> 1> 2> 3. Carapace brown turning yellow-brown, chelicerae, endites, and labium grey, sternum, spinnerets, and legs milk-white, legs covered with grey hairs. Female epigyne (Fig. 4A, B ): atrium inverted triangular, occupying 1/4 of epigyne, epigynal hood located located central laterally, posterior epigynal sclerite near trapezoidal, c. 3 times longer than wide, swell of epigyne near spherical and uniformly yellow, copulatory ducts originating centrally and near posteriorly, located centrally, extending anteriorly then curved inward, U-shaped, copulatory opening located centrally, on both sides of the midline, spermathecae coiled, fist-like, c. 1/6 the length of copulatory ducts, fertilization ducts slender and transparent, 5 times longer than wide.

Male. Unknown.

Distribution.

Vinh Phuc Province, Vietnam (Fig. 8 ).

Figures

Figure 2. Epigyne and habitus of Baiyuerius daxi sp. nov. A epigyne, ventral view B vulva, dorsal view C female habitus, dorsal view D female habitus, ventral view E female habitus, lateral view. Scale bar equal for C-E. Abbreviations: A = atrium; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct (white dotted lines); H = hood; PES = posterior epigynal sclerite; S = spermatheca; SE = swell of epigyne.

Figure 4. Epigyne and habitus of Baiyuerius tamdao sp. nov. A epigyne, ventral view B vulva, dorsal view C female habitus, dorsal view D female habitus, ventral view E female habitus, lateral view. Scale bar equal for C-E. Abbreviations: A = atrium; CD = copulatory duct (black dotted lines); CO = copulatory opening; FD = fertilization duct (white dotted lines); H = hood; PES = posterior epigynal sclerite; S = spermatheca; SE = swell of epigyne.

Figure 7. Epigyne and habitus of Baiyuerius zuojiang sp. nov. A epigyne, ventral view B vulva, dorsal view C male habitus, dorsal view D female habitus, dorsal view E female habitus, ventral view; Scale bar equal for C-E. Abbreviations: A = atrium; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct (white dotted lines); H = hood; PES = posterior epigynal sclerite; S = spermatheca; SE = swell of epigyne.

Figure 8. Localities of Baiyuerius species in China and Vietnam 1 B. daxi sp. nov. 2 B. pindong sp. nov. 3 B. tamdao sp. nov. 4 B. zhuping sp. nov. 5 B. zuojiang sp. nov.