Trichotichnus (s. str.) angustitarsis, 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 : 312-315

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

( Figs. 9 , 19, 21 , 23–28 )

Type material. Holotype. Male , “ CHINA, Yunnan Provin., Gongshan, Dulongjiang Bapo, along roadside 27.73902°N, 98.34975°E ”, “ 1412 m, 2004.11.3 night Liang Hongbin collector California Academy & IOZ., Chinese. Acad. Sci.” ( IOZ).

Paratypes. China. YUNNAN: 1 male, 1 female, Gongshan, Dulongjiang, Elidang village , beach, 28.00287°N 98.32145°E, 1640 m, 3.XI.2004, D. Kavanaugh leg. ( CAS) ; 1 male, 1 female, Gongshan, Dulongjiang, Maku , road, light trap, 27.68545°N 98.30419°E, 1814 m, 29.VIII.2006, Y. Liu leg. ( IOZ) ; 1 female, Gongshan, Dulongjiang , 1.0 km SW of Maku, 27.97775°N 98.29771°E, 1970 m, 29.VIII.2006, D. Kavanaugh, J.A. Miller leg. ( IOZ) ; 1 male, Gongshan, Dulongjiang , 0.5 km WSW Maku, trail, 27.68310°N 98.30038°E, 1845 m, 30.VIII.2006, D. Kavanaugh, J.A. Miller leg. ( CAS) ; 1 female, Gongshan, Dulongjiang, Kongdang , light trap, 27.87755°N 98.33612°E, 1511 m, 27.VIII.2006, Y. Liu leg. ( CAS) ; 2 males, 1 female, Longling Co., Longjiang, Xiaoheishan , tree & log, 24.83671°N 98.76185°E, 2067 m, 28.V.2005, H.M. Yan leg. ( IOZ, ZIN) ; 1 male, 3 females, Baoshan Pref. , mountain range 25 km S Tengchong, 1900 m, 24°48'28"N 98°32'03"E, devasted primary decid. forest, litter, sifted, 2.VI.2007, D.W. Wrase leg. [17] (cWR) ; 1 male, 6 females, same data but litter, fungi, sifted, M. Schülke leg. (cWR, ZIN) .

Laos. 1 male, “NE-LAOS Pr. Hua Phan Ban Saleul, Phou Pan (Mt.), ~ 20°12′N, 104°01′E, 01.–31.V.2011, 1300–1900 m, local collector” ( NME) .

Description (5 males and 5 females measured). Body length 10.0– 11.4 mm. Habitus as in Fig. 9 .

Dorsal side of body black or dark brown, shiny, slightly iridescent on elytra; ventral side blackish brown. Mandibles basally, labrum and narrow lateral margins of pronotum reddish or yellowish brown; palpi and antennae brownish yellow; legs brownish yellow or brown, occasionally femora slightly infuscate.

Head moderately sized (HWmax/PWmax 0.67–0.70, HWmin/PWmax 0.51–0.55). Eyes large and very convex, almost hemispherical (HWmax/HWmin 1.26–1.33), in lateral view almost round. Genae very narrow, narrower than antennomere 2 basally. Tempora very short, glabrous. Fronto-clypeal suture fine, shallow, slightly rounded. Frontoocular furrows fine, impressed at clypeus, reaching supraorbital furrows. Supraorbital furrows narrow, touching upper margin of eye. Supraorbital setigerous pores small, situated slightly before level of posterior margin of eye and removed from supraorbital furrows by distance approximately equal to width of antennomere 1; in some specimens one or two very small unsetigerous punctures present medially of each supraorbital seta. Labrum very shallowly concave anteriorly. Clypeus somewhat flat, slightly emarginate along anterior margin, with a pair of setigerous pores each located at anterior angle. Mentum separated from submentum, with moderately wide median tooth; epilobes narrow; submentum with one pair of long setae. Ligular sclerite markedly widened apically, truncate at apex, with one pair of ventroapical setae. Paraglossae narrow, markedly longer than ligular sclerite and separated from it by wide notches. Penultimate labial palpomere about as long as ultimate palpomere. Left mandible sharply bent in the apical fifth, blunted at tip. Dorsal microsculpture very fine, consisting of more or less isodiametric meshes, in some specimens highly obliterated. Antennae slender, surpassing pronotal basal edge by two apical antennomeres, with antennomeres 4–8 about three times as long as wide. Basal antennomere very slightly longer than antennomere 3.

Pronotum transverse (PWmax/PL 1.45–1.55), widest at the end of the anterior third (PWmax/PWmin 1.14– 1.19), more strongly narrowed apically than basally, with one lateral seta inserted in widest point. Sides rounded along entire length; lateral bead narrow, complete. Apical margin shallowly or moderately emarginate, very narrowly bordered along entire length, but occasionally border obliterated at the middle. Apical angles widely rounded, slightly protruding ahead. Basal margin slightly rounded in middle portion, scarcely oblique laterally, bordered along entire length, slightly longer than apical margin and slightly shorter than base of elytra between humeral angles. Basal angles very obtuse, with very small, occasionally almost indistinct obtuse denticle at tip. Disc moderately convex, strongly flattened at basal angles. Lateral depression very narrow in apical third, strongly widened in the basal half and fused with wide and shallow basal foveae; area between basal foveae convex. Median line distinct, superficial. Surface densely and finely punctate laterobasally and along sides, with sparser and finer punctures at base medially and at apical margin laterally. Microsculpture very fine, consisting of isodiametric (mostly anteriorly) and transverse meshes.

Elytra convex, elongate oval (EL/EW 1.44–1.54, EL/PL 2.85–3.14, EW/PWmax 1.28–1.38), widest in the apical third; sides slightly concave before the middle. Humeri angularly rounded, with a tiny denticle visible in caudal view. Subapical sinuation very shallow. Sutural angle acutangular, sharp or blunted at tip. Basal edge evenly arched or oblique, forming a very obtuse angle (internal humeral angle) with lateral margin. Striae impunctate, impressed along entire length, reaching anteriorly basal edge. Intervals slightly convex, moderately narrowed apically. Parascutellar (abbreviate) striole long, with a small setigerous pore basally. Interval 3 with a very small discal setigerous pore adjacent to stria 2 in the beginning of apical third (in one specimens two such pores present on each elytron). Marginal umbilicate series without distinct gap at middle. Microsculpture on intervals strongly obliterated, consisting of indistinct transverse lines.

Wings fully developed.

Prosternum with very fine short setae. Metepisternum ( Fig. 21 ) markedly longer than wide, strongly narrowed posteriorly.

Legs relatively short. Metacoxae without additional setae medially. Metafemur ventrally with two setae at posterior margin and without setae at anterior margin. Protibia on dorsal side without longitudinal sulcus, in both sexes with three similar sized preapical spines on outer margin ( Fig. 19 ). Tarsi glabrous dorsally, pro- and mesotarsomeres 1–4 in both sexes with comparatively sparse moderately long ventro-lateral setae; tarsomere 5 with three or four pairs of ventro-lateral setae. Metatarsus slender, almost as long as or slightly shorter than HWmax, with tarsomeres weakly widened distally; metatarsomere 1 slightly shorter than metatarsomeres 2 and 3 combined; metatarsomeres 1–4 moderately densely setose ventrally. In male, pro- and mesotarsomeres 1–4 comparatively weakly widened (only slightly wider than in female) and with adhesive scales ventrally; pro- and mesotarsomeres 2 and 3 longer than wide. In both sexes, mesotarsomere 1 elongate, about as long as mesotarsomeres 2 and 3 combined.

Abdominal sternites without additional long setae; last visible abdominal sternite (VII) with one pair of marginal setae in male and with two pairs in female, in both sexes rounded at apex, but in male more widely.

Median lobe of aedeagus ( Figs. 23–25 ) in lateral view arcuate on dorsal side, with ventral margin almost straight in middle portion and with apex angularly bent dorsally; ventral side edged laterally in apical part and flattened between margins; terminal lamella ( Fig. 23 ) in dorsal view wide, wider than long, concave, strongly narrowed posteriorly, with sides very slightly concave just before narrowly rounded apex. Apical orifice in dorsal position, wide apically. Internal sac without spines, with spiny patch apically.

Female genitalia ( Figs. 26 & 27 ): gonocoxite comparatively narrow in ventral view, about 0.6 times as long as gonosubcoxite, with wide base.

Etymology. The specific name is a Latin compound adjective, referring to the narrow pro- and mesotarsi of male.

Comparison. This new species is very similar in habitus to T. fukuharai , but differs in having pronotum relatively smaller, with deeper laterobasal depressions and more distinct microsculpture, and elytra with wider apical portions of intervals. In addition, the males of T. angustitarsis sp. n. are distinguished from those of T. fukuharai by having pro- and mesotarsi narrower (see Figs. 18 & 19 ), last abdominal sternite with one pair of marginal setae and very different structure of median lobe of aedeagus (bent terminal lamella apex, no thick spine in internal sac, etc.), as described above.

Distribution ( Fig. 28 ). Known from western Yunnan ( China) and North West Laos. The species occurs at altitudes of 1300–1970 m. The range of T. angustitarsis sp. n. is probably located to the west of the range of T. fukuharai .

Figures

FIGURE 28. Trichotichnus angustitarsis 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 23–27. Trichotichnus angustitarsis sp. n. 23, terminal lamella of aedeagus; 24 & 25, median lobe of aedeagus (holo- type); 26, gonocoxite; 27, laterotergite, gonosubcoxite, and gonocoxite (Kongdang). Dorsal (23 & 25), lateral (24 & 26) and ventral (27) views. Scale bars: A = 0.5 mm (23, 26 & 27), B = 1.0 mm (24 & 25).