Trilacuna yunmeng Ma & Tong, 2024

Ma, Jimeng, Chen, Qiang & Tong, Yanfeng, 2024, Four new species of the genus Trilacuna Tong & Li, 2007 (Araneae, Oonopidae) from China, ZooKeys 1219, pp. 331-346 : 331-346

Trilacuna yunmeng Ma & Tong sp. nov.

Figs 6 F , 9 , 10

Material examined.

Holotype: China • ♂ ( SYNU-1180 ); Hebei Province, Baoding City, Yi County, Yunmeng Mountain ; 39°23'52"N, 115°16'17"E; 11. VI. 2012; F. Zhang leg.

Etymology.

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

Diagnosis.

The new species is similar to Trilacuna hansanensis Seo, 2017 , but can be distinguished by the many ridges on posterior area of sternum (Fig. 9 E ), vs a pair of ridges ( Seo 2017: fig. 1 B), and the steeply elevated epigastric region (Fig. 9 H ) vs flat ( Seo 2017: fig. 1 B).

Description.

Male (Holotype). Body: yellow, legs lighter; habitus as in Fig. 9 A – C ; body length 1.57. Carapace: 0.67 long, 0.57 wide; sides granulate, lateral margin rebordered (Fig. 9 D ). Eyes: nearly equal sized; posterior eye row recurved from above, procurved from front; ALE separated from edge of carapace by 1.3 diameters (Fig. 9 D, G ). Mouthparts: chelicerae straight; labium rectangular, anterior margin deeply incised; endites slender, distally branched (Figs 6 F , 9 G ). Sternum: surface finely smooth, with many ridges on posterior area (Fig. 9 E ). Abdomen: 0.84 long, 0.57 wide; booklung covers ovoid, surface smooth; sperm pore situated at level of anterior spiracles; apodemes present, posterior spiracles not connected by groove; epigastric region steeply elevated (Fig. 9 C ). Leg spination: legs I – II: tibia: v 2-2 - 2 - 2 - 0, metatarsus: v 2-2 - 0. Palp: orange; 0.50 long (0.14, 0.11, 0.11, 0.14); femur elongated (width / length = 0.62); bulb triangular, basally strongly bulged; embolus system with ear-shaped projection (bep) at base, with a lateral curved branch (lcb) and narrow medial branch (mb) (Fig. 10 A – L ).

Female. Unknown.

Distribution.

Known only from the type locality (Fig. 11 ).

Figures

Figure 6. Trilacuna qingliangfeng sp. nov., female paratype (A, B), Trilacuna guangwu sp. nov., male holotype (C), Trilacuna qingliangfeng sp. nov., male holotype (D), Trilacuna taoyuanyu sp. nov., male holotype (E), Trilacuna yunmeng sp. nov., male holotype (F) A, B copulatory organ in ventral and dorsal views C – F endites in ventral view. Abbreviations: ap = apodemes; as = anterior sclerite; glo = globular structure; mr = membranous region; psp = posterior spiracle; sar = sclerotized, recurved arches; sdb = slightly curved distal branch; tsc = transverse bars. Scale bars: 0.4 mm (A, B); 0.2 mm (C – F).

Figure 9. Trilacuna yunmeng sp. nov., male holotype A – C habitus in dorsal, ventral and views D – G prosoma in dorsal, ventral, lateral and anterior views, arrow shows the small ridges H abdomen, lateral view, arrow shows the steeply elevated epigastric region. Scale bars: 0.4 mm (A – H).

Figure 10. Trilacuna yunmeng sp. nov., left male palp, A – F (light) and G – L (SEM) A, G prolateral view B, H dorsal view C, I retrolateral view D, J distal part of palpal bulb, prolateral view E, K distal part of palpal bulb, dorsal view F, L distal part of palpal bulb, retrolateral view. Abbreviations: bep = basal ear-shaped projection; lcb = lateral curved branch; mb = medial branch. Scale bars: 0.1 mm (A – C, G – I); 0.05 mm (D – F, J – L).

Figure 11. Distribution records of four new species from China. 1 = Trilacuna guangwu sp. nov.; 2 = Trilacuna qingliangfeng sp. nov.; 3 = Trilacuna taoyuanyu sp. nov.; 4 = Trilacuna yunmeng sp. nov.