Trilacuna difeng Tong & Li, 2021

Wang, Ying, Tong, Yanfeng, Bian, Dongju & Li, Shuqiang, 2021, Two new species of the genus Trilacuna from Chongqing Municipality, China (Araneae, Oonopidae), Zootaxa 4927 (3), pp. 431-443 : 433

Trilacuna difeng Tong & Li , sp. nov.

Figs 1 , 2 A–D, 3, 4, 5A–B, 9

Type material. Holotype: Male (SYNU-264), Difeng National Park (26º10'45.93''N, 105º28'44.886''E, elevation 1438 m), Fengjie County, Chongqing Municipality, China, 23 October 2014, S. Lyu and Y. Tong leg. Paratypes: 2 males (SYNU-265–266) and 3 females (SYNU-267–269), same data as holotype . Other materials examined: 1 male (SYNU-270) and 3 females (SYNU-271–273), same data as holotype .

Etymology. The specific name is a noun in apposition from the type locality.

Diagnosis. This new species is similar to Trilacuna gongshan Tong, Zhang & Li, 2019 , but males can be distinguished by the broad sickle-shaped branch of embolus system ( Fig. 3E, H ), and females by the large globular structure of the endogyne ( Fig. 5B ). T. gongshan males have three long, tooth-like lobes of embolus system, and females have a very small globular structure of endogyne ( Tong et al. 2019: figs 11B, D, 24H).

Description. Male (holotype, SYNU-264). Body yellow, chelicerae and sternum lighter. Habitus as in Fig. 1A, C, E . Body length 1.97; carapace 0.93 long, 0.76 wide; abdomen 1.03 long, 0.68 wide. Carapace sides granulate; lateral margin rebordered. Six eyes, well developed, arranged in a compact group; ALE, PME and PLE subequal; ALE-PLE separated by less than ALE radius, PME touching each other; posterior row recurved from above, procurved from front ( Fig. 1B, I ). Clypeus sinuous in frontal view, anterior lateral eyes separated from edge of carapace by about 1.4 times their diameter. Mouthparts: chelicerae straight, proximal region with one hair with elevated hair base; labium rectangular, anterior margin deeply incised ( Fig. 1D ); endites slender, distally strongly branched ( Fig. 1D ). Sternum with radial furrows between coxae I-II, II-III, III-IV; surface medially strongly reticulated ( Fig. 1D ). Abdomen ( Fig. 1G, H ): booklung covers ovoid, surface smooth; dorsal scutum not fused to epigastric scutum; apodemes present, posterior spiracles not connected; sperm pore oval, situated between anterior and posterior spiracles. Leg spination (all spines longer than segment width): legs I-II: tibia: v2-2-2-2-0, metatarsus: v2-2-0. Palp ( Figs 2 A–D, 3): orange; 0.62 long (0.19, 0.14, 0.14, 0.15); femur greatly swollen (width/length = 0.68); bulb oval, tapering apically; embolus system ( Fig. 3E, F, H ) with a broad sickle-shaped branch (ssb) in prolateral view, a median branch (mb) in dorsal view, and a lateral curved branch (lb) in retrolateral view.

Female (SYNU-267): Same as male except as noted. Habitus as in Fig. 4A, C, E ; slightly larger than male. Body length 2.02, carapace 0.91 long, 0.76 wide, abdomen 1.15 long, 0.72 wide. Endites: unmodified. Epigastric area ( Figs 4G , 5A ): surface without external features. Endogyne ( Fig. 5B ): with narrow, transverse sclerite (tsc), an anterior stick-shaped sclerite (as), and a posterior large globular structure (glo); transverse bar (tba) with two lateral apodemes (ap).

Distribution. Known only from the type locality ( Fig. 9 ).

Figures

FIGURE 1. Trilacuna difeng sp. nov., holotype male.A, C, E. Habitus (A. Dorsal view; C. Ventral view; E. Lateral view); B, D, F, I. Prosoma (B. Dorsal view; D. Ventral view; F. Lateral view; I. Anterior view); G–H.Abdomen (G. Ventral view; H.Anterior view). ehb = elevated hair base, ldi = labium deep incision, sdb = strongly curved distal branch. Scale bars: 0.40 (A–I).

FIGURE 2. Trilacuna difeng sp. nov., holotype male (A–D) and Trilacuna wenfeng sp. nov., holotype male (E–H). A–B, E–F. Left male palp (A, E. Prolateral view; B, F. Retrolateral view); C–D, G–H. Distal part of palp (C, G. Prolateral view; D. Retrolateral view; H. Dorsal view). Scale bars: 0.20 (A, B), 0.10 (C, D, E, F, G), 0.05 (H).

FIGURE 3. Trilacuna difeng sp. nov., holotype male, SEM. A–B. Left palp (A. Prolateral view; B. Retrolateral view); C–D, G. Palpal bulb (C. Prolateral view; D. Retrolateral view; G. Dorsal view); E–F, H. Distal part of palpal bulb (E. Prolateral view; F. Retrolateral view; H. Dorsal view). bp = basal projection, lb = lateral branch, mb = median branch, ssb = sickle-shaped branch, spr = small projection, tll = tooth-like lobes.

FIGURE 4. Trilacuna difeng sp. nov., paratype female. A, C, E. Habitus (A. Dorsal view; C. Ventral view; E. Lateral view); B, D, F, H. Prosoma (B. Dorsal view; D. Ventral view; F. Lateral view; H. Anterior view); G. Abdomen, ventral view. ehb = elevated hair base, ldi = labium deep incision. Scale bars: 0.40 (A–H).

FIGURE 5. Trilacuna difeng sp. nov., paratype female (A–B) and Trilacuna wenfeng sp. nov., paratype female (C–D). Copulatory organ (A, C. Ventral view; B, D. Dorsal view). ap = apodeme, as = anterior sclerite, glo = globular structure, psp = posterior spiracle, sar = sclerotized, recurved arches, tba = transverse bar, tsc = transverse sclerite. Scale bars: 0.20 (A, B), 0.10 (C, D).

FIGURE 9. Distribution records of the species of Trilacuna from China. 1. T. angularis Tong & Li, 2007; 2. T. bawan Tong, Zhang & Li, 2019; 3. T. cuneata Tong, 2019; 4. T. datang Tong, Zhang & Li, 2019; 5. T. difeng sp. nov.; 6. T. fugong Tong, Zhang & Li, 2019; 7. T. gongshan Tong, Zhang & Li, 2019; 8. T. longling Tong, Zhang & Li, 2019; 9. T. rastrum Tong & Li, 2007; 10. T. simianshan Tong & Li, 2018; 11. T. songyuae Tong & Li, 2018; 12. T. wenfeng sp. nov.; 13. T. wuhe Tong, Zhang & Li, 2019; 14. T. xinping Tong, Zhang & Li, 2019.