Trechus (Trechus) luzhangensis Deuve and Liang, 2016

Deuve, Thierry, Kavanaugh, David H. & Liang, Hongbin, 2016, Inventory of the Carabid Beetle Fauna of the Gaoligong Mountains, Western Yunnan Province, China: Species of the Tribe Trechini (Coleoptera: Caraboidea), with Descriptions of Four New Genera, One New Subgenus and 19 New Species., Proceedings of the California Academy of Sciences 63 (12), pp. 341-455 : 397-400

Trechus (Trechus) luzhangensis Deuve and Liang , sp. nov.

( Figs. 22 , 43a , 46–48 )

TYPE MATERIAL.— Holotype, a male, in IOZ, labeled: “CASENT 1017595”/ “ CHINA, Yunnan, Lushui County, Luzhang Township, Piana Road at Fengxue Yakou , N25.97228° / E98.68336°, 3150 m, 11 May 2005,”/ “Stop# 2005-007, D.H. Kavanaugh , H.B. Liang, C.E. Griswold, D.Z. Dong & K.J. Guo collectors”/ “ HOLOTYPE Trechus luzhangensis Deuve & Liang , sp. nov. designated 2016” [red label] . Paratypes (only 1): a female (in CAS) labeled same as holotype, except first label “CASENT 1017596” and last label “ PARATYPE Trechus luzhangensis Deuve & Liang , sp. nov. designated 2016” [yellow label] .

TYPE LOCALITY.— China, Yunnan, Lushui County, Luzhang Township, Pianma Road at Fengxue Yakou [Pass], N25.97228° / E98.68336°, 3150 m .

ETYMOLOGY.— The species epithet, luzhangensis , is derived from the name of the township, Luzhang, in which the type locality is found, and the Latin suffix, -ensis, denoting place.

DIAGNOSIS.— Adults of this species ( Fig. 22a ) can be distinguished from those of all other species in the region by the following combination of character states: size medium (BL = 3.7 to 3.8 mm), apterous; body color dark piceous, shiny, elytra with interval 1, lateral margins and apicomedial area reddish; tempora glabrous, convex, half as long as diameter of eyes; pronotum transverse (ratio PW/PL = 1.46), basal angles rectangular and sharp; elytra ovoid, convex, striae finely impressed, striae 1 to 3 deeply impressed on disc, not attenuated apically, remaining striae successively less distinct, the outermost very faint but still evident; recurrent stria terminated anteriorly at distinct convexity of interval 7; two discal setae present, inserted on interval 3 next to stria 3; preapical seta present and inserted in a discal position on interval 3, near stria 2 in forward position near apical one-fourth of elytra; median lobe of male aedeagus ( Fig. 22b ) with moderate-sized sagittal aileron, apical lamella short and thick, with apex blunt, endophallus with a sclerotized line and a scaly area.

DESCRIPTION.— Size medium, BL = 3.7 to 3.8 mm. Body color dark piceous, shiny, elytra with interval 1, lateral margins and apicomedial area more or less reddish, appendages paler, yellowish-orange, palpi pale yellow. Body surface smooth, head capsule faintly alutaceous.

Head. Moderate in size; eyes only slightly projected but convex, their diameter twice as long as tempora, the latter short, moderately convex and glabrous. Frons not flattened; frontal furrows deep, rounded, prolonged and not attenuated posterior to the eyes. Two pairs of supraorbital setae present, the anterior pair inserted in foveae. Clypeus with four setae. Labrum with six setae, anterior margin distinctly concave. Mandibles short; right mandible distinctly tridentate with middle tooth closer to basal tooth (premolar) than to distal tooth. Mentum and submentum not fused but nearly so, suture between them only faintly impressed. Mentum with medial tooth apically truncate, less than half the length of the lateral lobes. Submentum with six setae anteriorly, swollen anteriorly. Gula wide. Genae with a single seta ventrally on each side. Antennae rather short, with about 2 antennomeres extended posteriorly beyond basal pronotal margin; antennomeres 2 and 3 about equal in length, antennomere 4 slightly shorter.

Pronotum. Transverse (ratio PW/PL = 1.46), moderately narrowed posteriorly, greatest width anterior to middle; lateral margins widely rounded, straightened only just anterior to basal angles, the latter very small, but projected, acute and sharp. Disc convex, smooth and glabrous, median longitudinal impression slender but sharply impressed, extended anteriorly to near anterior margin; basal foveae distinct, subcircular; median basal area faintly, longitudinally rugulose, delimited laterally by obliquely curved furrows. Lateral borders of pronotum moderately slender, narrowly reflexed, lateral grooves deeply impressed. Single midlateral setae on each side inserted near anterior one-third; single basolateral seta on each side, inserted at basal angle.

Elytra. Ovoid, only slightly more narrowed basally than apically, humeri distinct but rounded. Disc convex and smooth. Striae finely impressed, not or only faintly punctate; striae 1 to 3 deeply impressed on disc, not attenuated apically, remaining striae successively less distinct, the outermost very faint but still evident. Parascutellar striole present. Recurrent stria terminated anteriorly at distinct convexity of interval 7. Basal setiferous pore present at common origin of striae 1 and 2. Two discal setae present and inserted next to stria 3, one at anterior one-fourth and one near middle of elytra. Preapical seta present and inserted in a prediscal position on interval 3, closer to stria 2 than 3 in forward position at apical one-fourth of elytra. Umbilicate setae of humeral group equidistance from each other and setae of median group inserted slightly posterior to middle.

Legs. Relatively short, protibiae with longitudinal furrow. Male protarsomeres 1 and 2 dilated and apicomedially toothed.

Abdomen. Abdominal ventrites glabrous, except for a single paramedial seta on each side, and ventrite VII of males apically with one pair of paramedial setae, of females with two pairs.

Male aedeagus. Median lobe ( Fig. 22b ) only moderately enlarged basally but with a mediumsized sagittal aileron present; shaft narrow subbasally, progressively thicker toward subapical portion; apical lamella short and thick, with apex blunt, endophallus with a sclerotized line and a scaly area, similar to that seen in males of T. shiyueliang sp. nov. ( Fig. 18b ).

HABITAT DISTRIBUTION.— Members of this species have been found under stones on slopes above ( Fig. 43a ) and below the road and both side of the pass at an elevation of 3150 m. The habitat in this area includes broken scrub vegetation of two to four meter high bamboo and Rhododendron thickets on a thin layer of organic substrate, as well as open areas with stones on granitic sand substrate, and small seeps. Both specimens were found at the edges of thickets on organic substrate. No other trechines were found at this site.

GEOGRAPHICAL DISTRIBUTION WITHIN THE GAOLIGONG SHAN. Fig. 22c . We examined a total of 2 specimens (1 male and 1 female), both from the crest of the southcentral part of the Gaoligong Shan in Lushui County (see Type material above for exact collection data). This locality straddles Core Areas 4 and 5 .

OVERALL GEOGRAPHICAL DISTRIBUTION. This species currently is known only from the type locality on the crest of the southcentral part of the Gaoligong Shan , in western Yunnan Province, China .

Figures

FIGURE 22. Trechus luzhangensis sp. nov.; a. Dorsal habitus (CASENT1017595). b. Median lobe of aedeagus of male (CASENT1017595), left lateral aspect. c. Map of locality records (red circles) for T. luzhangensis in the Gaoligong Shan region. Scale lines a, b = 0.5 mm, c = 100 km.

FIGURE 43. Photographs of habitats for trechine species in the Gaoligong Shan region. a. Lushui County, Luzhang Township, Piana Road 0.1 km E of Fengxue Yakou, elevation 3150 m; habitat in which specimens of Trechus luzhangensis sp. nov. were collected. b. Lushui County, Luzhang Township, 100 m S of Fengxue Yakou on east side of pass, elevation 3150 m; habitat in which specimens of Trechepaphiopsis unisetosa (Deuve) were collected. Photos by David H. Kavanaugh.

FIGURE 46. Chart showing the representation of trechine species in project-designated Core Areas (see Fig. 3) in the Gaoligong Shan region.

FIGURE 47. Chart illustrating the altitudinal ranges of trechine species represented in the Gaoligong Shan region.

FIGURE. 48. Chart illustrating the co-occurence (syntopy) of trechine species in samples from the same habitats and at the same sites in the Gaoligong Shan region.

FIGURE 18. Trechus shiyueliang sp. nov.; a. Dorsal habitus (CASENT1021004). b. Median lobe of aedeagus of male (CASENT1021004), left lateral aspect. c. Map of locality record s(red circles) for T. shiyueliang in the Gaoligong Shan region. Scale lines a, b = 0.5 mm, c = 100 km.