Trilacuna songyuae Tong & Li

Tong, Yanfeng, Guan, Xijin & Li, Shuqiang, 2018, Two new species of the genus Trilacuna from Chongqing, China (Araneae, Oonopidae), ZooKeys 771, pp. 41-56 : 41

Trilacuna songyuae Tong & Li sp. n. Figs 6, 7, 8, 9, 10

Type material.

Holotype ♂, (SYNU-101), China, Chongqing Municipality, Jiangjin Dist., Simianshan Natural Reserve, Dawopu, 28°34'43.956"N, 106°21'2.424"E, 28 m, 20.X.2014, leg. S. Lyu and Y. Tong. Paratypes: 2 ♂, 2 ♀ (SYNU-101), same data as holotype; 5 ♂, 4 ♀ (SYNU-102), same data as holotype; 7 ♂, 5 ♀ (IZCAS Ar-25088), China, Chongqing Municipality, Jiangjin Dist., Simianshan Natural Reserve, Dawopu, 28°35'14.628"N, 106°22'44.790"E, 1000 m, 20.X.2014, leg. S. Lyu and Y. Tong.

Other material studied.

7 ♂, 1 ♀ (SYNU-103), same data as holotype; 8 ♂, 2 ♀ (SYNU-105), China, Chongqing Municipality, Jiangjin Dist., Simianshan Natural Reserve, Dawopu, 28°35'14.628"N, 106°21'44.790"E, 1000 m, 20. X. 2014, leg. S. Lyu and Y. Tong.

Etymology.

The specific name is after Miss Songyu Lyu (吕松宇), one of the collectors of this species.

Diagnosis.

The new species is similar to T. hansanensis Seo, 2017. Both species have an elevated ridge on the posterior part of the male sternum, but can be distinguished by the long oval bulb, the very long setae (nls) on the prolateral surface of the male palpal tibiae and the two small, spear-like setae (sps) on the basal part of the prolateral surface of male palpal cymbium. Trilacuna hansanensis has a pear-shaped bulbus, and there are no special setae on the male palpal tibia or cymbium (see Seo 2017: figs 1 A–K).

Description.

Male. Body yellow-brown, chelicerae and sternum lighter, legs yellow. Habitus as in Fig. 6 A–C. Body length 1.87; carapace 0.86 long, 0.73 wide; abdomen 0.97 long, 0.71 wide. Carapace sides granulate; lateral margin rebordered, with a row of short, fine hairs and small, blunt denticles. Eyes six, well developed, arranged in a compact group; ALE largest, PLE smallest; ALE–PLE separated by less than ALE radius, PME touching each other; posterior row recurved from above, procurved from front (Fig. 6D, G). Clypeus sinuous in frontal view, anterior lateral eyes separated from edge of carapace by about 2.0 times their diameter, with needle-like setae. Mouthparts: chelicerae straight, proximal region with one hair with elevated hair base (ehb); labium rectangular, anterior margin deeply incised (ldi) (Fig. 6E); endites slender, distally slightly branched (sdb) (Fig. 6B). Sternum with radial furrows between coxae I–II, II–III, III–IV; lateral margin smooth, middle area reticulate, posterior part with two slightly elevated ridges, each covered with a row of short, strong setae, the region between the two ridges strongly wrinkled (Fig. 6E). Abdomen: booklung covers (boc) large, ovoid, surface smooth (Fig. 7B). Dorsal scutum not fused to epigastric scutum. Apodemes present, posterior spiracles not connected by groove (Fig. 7A). Leg spination (all spines longer than segment width): legs I‒II: tibiae: v2-2-2-2-0, metatarsi: v2-2-0, leg IV: femur with very long hairs ventrally (Fig. 7F). Trichobothria: tibia: each with 3; metatarsus: each with 1.

Genitalia. Epigastric region (Fig. 7A) with sperm pore small, oval, rebordered, situated before anterior spiracles; with a small dark dot (dd) between the posterior spiracles, a cluster of long hairs around the dark dot. Palp (Figs 7C, D, 8): orange. 0.42 long (0.14, 0.07, 0.10, 0.11). Femur strongly swollen (width/length = 0.08/0.14) (Fig. 7C, D). Tibia with numerous, very long, penniform setae (nls) on prolateral surface and two long, strong setae (tss) on retrolateral surface (Fig. 7C, D). Cymbium with two small, spear-like setae (sps) on basal part of prolateral surface (Figs 7C, 8G, H). Bulb long, oval, stout, tapering apically. Embolus system (Fig. 8B, D, F) complex, bearing numerous small “papillae”; with a strongly sclerotized, sickle-shaped protuberance (ssp) and a fan-shaped outgrowth (sso) prolaterally; between the two outgrowths is a cluster of long, line-like structures (cll); with a ribbon-like, nearly transparent outgrowth (rlo) and a broom-like outgrowth (blo) retrolaterally.

Female. As in male except as noted. Slightly larger than male. Body length 1.91; carapace 0.89 long, 0.75 wide; abdomen 1.02 long, 0.78 wide. Postepigastric scutum long. Posterior spiracles connected by groove (Fig. 10B).

Genitalia. Ventral view (Fig. 10H): surface without external features, a dark knob-like marking (dk) can be seen through the cuticle. Dorsal view (Fig. 10I): with a very small, cone-shaped structure (css). Transverse bars with two relatively long, lateral apodemes.

Distribution.

China (Chongqing).