Trichotichnus (s. str.) subrobustus, Kataev & Hongbin & Wrase, 2022

Kataev, Boris M., Hongbin, Liang & Wrase, David W., 2022, New data on carabid beetles of Trichotichnus s. str. (Coleoptera: Carabidae) of Yunnan (China) and adjacent areas, with description of six new species and two new subspecies, Zootaxa 5159 (3), pp. 301-353 : 316-319

Trichotichnus (s. str.) subrobustus sp. n.

( Figs. 10 , 22 , 29–34 )

Type material. Holotype. Male , “ CHINA, Yunnan Provin., Gongshan, Dulongjiang Bapo, Mabiluo, riverside 27.76208°N, 98.34567°E ”, “ 1503 m, 2004.10.27 day Liang Hongbin collector California Academy & IOZ., Chinese. Acad. Sci.” ( IOZ).

Paratypes. China. YUNNAN: 1 male, Gongshan Co., Dulongjiang, Elidang Village , beach, 28.00287°N 98.32145°E, 1640 m, 3.XI.2004, D. Kavanaugh, D.Z. Dong leg. ( ZIN) ; 1 female, Gongshan, Dulongjiang , 0.5 km N Kongdang, 27.88111°N 98.34062°E, 1500 m, 7.XI.2004, D. Kavanaugh leg. ( IOZ) ; 1 female, Gongshan, Dulongjiang , 0.6 km N Dizhengdang, 28.08442°N 98.32652°E, 1880 m, 29.X.2004, D. Kavanaugh leg. ( CAS) ; 1 female, Gongshan, Dulongjiang, Moqiewang , riverside, 27.89924°N 98.35877°E, 1580 m, 6.XI.2004, H.B. Liang leg. ( CAS) .

Description (2 males and 3 females measured). Body length 9.2–10.0 mm. Habitus as in Fig. 10 . Morphological character states are as described for H. angustitarsis sp. n., but differing or limited as follows.

Dorsal side of body black, shiny, very slightly iridescent on elytra; ventral side blackish brown. Base of mandibles and occasionally the very narrow lateral margins of pronotum reddish brown; palpi and antennae brownish yellow; legs brownish yellow or light brown, occasionally femora very slightly infuscate.

Head comparatively large (HWmax/PWmax 0.71–0.74, HWmin/PWmax 0.58– 0.62). Eyes smaller and less convex than in T. angustitarsis sp. n. (HWmax/HWmin 1.17–1.27), in lateral view oval. Genae wider, about as wide as antennomere 1. Tempora longer (about 0.3–0.4 as long as eye diameter and more oblique. Fronto-clypeal suture more impressed and clypeus more convex. Supraorbital furrows slightly wider. Supraorbital setigerous pores situated slightly behind level of posterior margin of eye and removed from supraorbital furrows by distance wider than width of antennomere 1. Left mandible sharply bent approximately in the apical quarter, subtruncate at tip. Dorsal microsculpture highly obliterated, meshes on frons not recognizable. Antennae shorter, not reaching pronotal basal edge, with antennomeres 4–8 about 2.7–3.0 as long as wide. Basal antennomere about as long antennomere 3.

Pronotum similar to that of T. angustitarsis sp. n. (PWmax/PL 1.50–1.58), also widest at the end of the anterior third, but more strongly narrowed basally (PWmax/PWmin 1.22–1.26), slightly more convex, more deeply emarginate apically and with apical angles more narrowly rounded. Microsculpture even more obliterated, meshes not recognizable medially on disc in some specimens.

Elytra relatively shorter (EL/EW 1.45–1.49, EL/PL 2.81–2.98; EW/PWmax 1.26–1.30), with less distinct humeral denticle, acuter sutural angle and narrower and more convex intervals apically; discal pore on interval 3 more distinct.

Metepisternum ( Fig. 22 ) shorter, only slightly longer than wide.

Tarsi shorter; metatarsus slightly shorter than HWmin; metatarsomeres 1–4 comparatively sparsely setose ventrally. In male, pro- and mesotarsomeres 1–4 comparatively weakly widened, with tarsomeres 2 and 3 about as long as wide. In both sexes, mesotarsomere 1 shorter than mesotarsomeres 2 and 3 combined.

Median lobe of aedeagus ( Figs. 29–31 ) robust, with a small transverse apical capitulum, in lateral view arcuate on dorsal side; its ventral margin almost straight in middle portion and slightly convex before apex; ventral side edged laterally in apical part and very shallowly depressed between margins; terminal lamella ( Fig. 29 ) in dorsal view wide and short, much wider than long, concave, with sides roundly converging to very widely rounded apex. Apical orifice in dorsal position, wide apically. Internal sac with a small, angularly curved apical spine.

Female genitalia ( Figs. 32 & 33 ): gonocoxite comparatively narrow and weakly curved in ventral view, about 0.7 times as long as gonosubcoxite, with moderately wide base.

Etymology. The specific name is a combination of the Latin prefix sub - and the Latin adjective robustus, referring to the rather robust body.

Comparison. In combination of characters, including coloration, shape of pronotum, not sulcate protibia with three similar sized preapical spines on outer margin and one pair of marginal setae on last abdominal sternite of male, this new species is similar to T. angustitarsis sp. n., but well differing from it in having body smaller, more robust, appendages shorter, head larger, genae wider, left mandible subtruncate at apex and metepisternum shorter. In the same characters and having one pair of marginal setae on last abdominal sternite of male, T. subrobustus sp. n. also differs from T. fukuharai which shares with the latter new species strongly obliterated dorsal microsculpture and rather narrow and markedly convex elytral intervals apically. Other distinctive characters of T. subrobustus sp. n. are listed in the description.

Distribution ( Fig. 34 ). Known from northwestern Yunnan ( China), within Gongshan County, where it occurs at altitudes of 1500–1880 m. This new species occurs sympatricly with T. angustitarsis sp. n.

Figures

FIGURE 34. Trichotichnus subrobustus sp. n., distribution.

FIGURES 8–10. Trichotichnus spp., habitus. 8, T. fukuharai Habu, 1957 (Yunnan); 9, T. angustitarsis sp. n. (S Tengchong); 10, T. subrobustus sp. n. (holotype). Scale bar = 1.0 mm.

FIGURES 18–22. Trichotichnus spp. (18–20, right male protarsus; 21 & 22, left metepisternum). 18, T. fukuharai Habu, 1957; 19 & 21, T. angustitarsis sp. n.; 20, T. hamulipenis sp. n.; 22, T. subrobustus sp. n. Scale bar = 0.5 mm.

FIGURES 29–33. Trichotichnus subrobustus sp. n. 29, terminal lamella of aedeagus; 30 & 31, median lobe of aedeagus (holo- type); 32, gonocoxite; 33, laterotergite, gonosubcoxite, and gonocoxite (N Dizhengdang). Dorsal (29 & 31), lateral (30 & 32) and ventral (33) views. Scale bars: A = 0.5 mm (29, 32 & 33), B = 1.0 mm (30 & 31).