Trilacuna guangwu 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 guangwu Ma & Tong sp. nov.

Figs 1 , 2 , 6 C

Material examined.

Holotype: China • ♂ ( SYNU-1179 ); Sichuan Province, Bazhong City, Nanjiang County, Guangwu Mountain, Taoyuan Scenic Area ; 32°40'48"N, 106°48'12"E; 5. VIII. 2014; 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 angularis Tong & Li, 2007 , but can be distinguished by the large, thorn-like structure (tls) and brush-like structure (bls) of embolus system (Fig. 2 D, E, J, K ) vs lacking, but with several strongly sclerotized sclerites ( Tong and Li 2007: fig. 15–18), and slightly elevated epigastric region (Fig. 1 H ) vs flat ( Tong and Li 2007: fig. 14).

Description.

Male (Holotype). Body: reddish brown, chelicerae and sternum lighter, legs yellow; habitus as in Fig. 1 A – C ; body length 2.05. Carapace: 1.06 long, 0.81 wide; sides granulate, lateral margin rebordered (Fig. 1 D ). Eyes: nearly equal sized; posterior eye row straight from above, procurved from front; ALE separated from edge of carapace by 1.4 diameters (Fig. 1 D, F ). Mouthparts: chelicerae straight; labium rectangular, anterior margin deeply incised; endites slender, distally not branched, with a membranous region (Figs 1 E , 6 C ). Sternum: surface rugose (Fig. 1 E ). Abdomen: 1.01 long, 0.65 wide; booklung covers ovoid, surface smooth; sperm pore situated at level of anterior spiracles; apodemes present, posterior spiracles connected by groove; epigastric region slightly elevated (Fig. 1 G, H ). Leg spination: legs I-II: tibia: v 2-2 - 2 - 2 - 0, metatarsus: v 2-2 - 0. Palp: orange; 0.66 long (0.21, 0.15, 0.15, 0.15); femur greatly enlarged (width / length = 0.74); bulb quadrangular; embolus system with a large, thorn-like structure (tls), a cluster of brush-like structure (bls), a broad median branch (mb) and a narrow lateral curved branch (lcb) (Fig. 2 A – L ).

Female. Unknown.

Distribution.

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

Figures

Figure 1. Trilacuna guangwu sp. nov., male holotype A – C habitus in dorsal, ventral and lateral views D – F prosoma in dorsal, ventral and anterior views G – H abdomen, ventral and lateral views, arrow shows the elevated epigastric region. Scale bars: 0.4 mm (A – H).

Figure 2. Trilacuna guangwu 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: bls = brush-like structure; lcb = lateral curved branch; mb = medial branch; tls = thorn-like structure. Scale bars: 0.1 mm (A – C, G – I); 0.05 mm (D – F, J – L).

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 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.