Laemostenus (Pristonychus) zhamensis, Zhu & Shi & Liang, 2021

Zhu, Pingzhou, Shi, Hongliang & Liang, Hongbin, 2021, The first record of the genus Laemostenus from China, with descriptions of two new species from the Himalaya (Carabidae, Sphodrini, Sphodrina), ZooKeys 1017, pp. 77-88 : 77

Laemostenus (Pristonychus) zhamensis sp. nov. Figs 2 , 6-8 , 12-14

Type locality.

China, Xizang: Nyalam (27.9815°N, 85.9770°E), altitude 2163 m.

Type material.

Holotype: male (IZAS), body length 15.9 mm, pin mounted, with genitalia dissected and glued on cardboard pinned under the specimen; labeled: "CHINA: Xizang, Xigazê Prefecture, Nyalam County, 100 m lower of Zham Town, 27.9815°N 85.9770°E, 2163m"; "2010.VII.26, along road, Zhu Xiaoyu lgt., Institute of Zoology, IZAS 聂拉木县樟木镇下 100 m"; "Holotype ♂ Laemostenus (Pristonychus) zhamensis sp. n. des. Zhu, Shi & Liang 2020" [red label].

Diagnosis.

Body dark brown. Head medium in width. Eyes very small, hardly prominent laterally; temporae slightly swollen, twice as long as eyes. Elytra with lateral margins distinctly sinuate near sutural angles; sutural angles rounded. Parascutellar pores absent. Ventral side of profemora smooth, with one seta on posterior margin, without tooth on anterior margin. Mesotibiae faintly curved in males. Meso- and metatibiae inner sides with a dense brush of reddish yellow setae in apical half. Metatrochanters reniform, not elongate. Apical lamella of median lobe short, length half its basal width, apex slightly truncate, somewhat rounded. Right paramere strongly curved (the angle between basal and apical portions near 120°), slightly widened at middle and slightly narrowed apically, apex moderately thin.

Comparison.

This new species also belongs to the Laemostenus brunneus species group, as does the previous new species.

It is distinguishable from most species of this group by the absence of the parascutellar pores on the elytra. There are three other species in this species group which have this character: Laemostenus (Pristonychus) tentiobtusus (Morvan, 1979), L. (P.) brunneus (Hope, 1831), and L. (P.) pseudobrunneus Casale, 1981, from India and Nepal. Laemostenus (P.) zhamensis sp. nov. differs from the first by the ventral side of profemora not having a tooth on the anterior margin, and it differs from the latter two species by the narrower and not globular head and the shallow and impunctate striae of the elytra.

Description

(male). BL = 15.9 mm, BW = 5.5 mm. Body (Fig. 2 ) dark brown, without metallic luster; labial and maxillary palpi and apex of mouthparts light brown; venter light brown. Head and pronotum with weak isodiametric microsculpture, elytra with strong isodiametric microsculpture.

Head (Fig. 6 ) medium in width. Vertex smooth; frontal impressions reduced to two small pits in front of eyes, which are shallow but distinct; anterior margin of labrum emarginate, with six setae; eyes very small, hardly prominent laterally; tempora slightly swollen, twice as long as eyes; two pairs of supraorbital setae present; antennae long and slender, extending to basal one-third of elytra.

Pronotum (Fig. 7 ) narrow, width subequal to length, PW/PL = 1.03, widest near anterior quarter; apical margin nearly straight, its width subequal to basal margin; sides distinctly converged to base (PW/PBW = 1.23), moderately sinuate before posterior angles, with two pairs of setae, at widest points of pronotum and at posterior angles, respectively; basal margin almost straight; anterior angles rounded, distinctly projecting forward; posterior angles forming distinct right angles; disc gently convex, smooth; median line fine but clearly defined, not reaching anterior and posterior borders; basal foveae deep and wide, extending to middle of pronotum, without punctures and wrinkles.

Elytra elongate, EL/EW = 1.65, slightly dilated towards apex, widest at posterior third; lateral margins distinctly sinuate near sutural angles; sutural angles rounded (Fig. 8 ); basal ridges straight; shoulders strongly oblique; shoulder angles between basal and lateral margins forming obtuse angles; humeral teeth very small, not pointed; striae shallow, impunctate; parascutellar striae well developed, short, located between suture and stria 1; parascutellar pores absent; intervals feebly convex, interval 3 without setigerous pores, interval 7 with one setigerous pore near apex; umbilicate series composed of 16 or 17 setigerous pores, very sparser in middle. Hind wings reduced.

Venter. Propleuron, mesepisternum, and metepisternum smooth. Mesosternum not denticulate in front of mesocoxae. Metepisternum slightly longer than wide. All abdominal sternites with a few shallow wrinkles laterally, without ambulatory setae.

Legs long and slender; ventral side of profemora smooth, with one seta on posterior margin, without tooth on anterior margin; protibiae with sparse pubescence on apices; mesotibiae faintly curved (in male); meso- and metatibiae with a dense brush of reddish yellow setae in apical half of their inner sides; metatrochanters reniform, not elongate; tarsi elongate and narrow; metatarsomere 1 sparsely pubescent dorsally; claws smooth on internal margin. Protarsomeres 1-3 (in male) distinctly dilated and with ventral adhesive vestiture.

Male genitalia. Median lobe (Fig. 12 ) short and stout, distinctly bent ventrally; apical orifice very long, stretching from basal bulb to apical lamella, not narrowed in middle; in dorsal view, left and right straightly converged to apex and rounded to base; apical lamella short, length half its basal width, apex slightly truncate, somewhat rounded; in lateral view, ventral margin straight, not expanded at the middle; apex slightly thickened, faintly bent ventrally at tip; left paramere (Fig. 14 ) large and round, apical membranous filament small; right paramere (Fig. 13 ) markedly styloid; strongly curved (the angle between basal and apical portions near 120°), slightly widened in middle, slightly narrowed apically, apex moderately thin.

Female unknown.

Distribution and habitat.

This species is only known from Zham Town, Nyalam County, Xizang, China (Fig. 15 ). The only specimen was caught along road during day in a cloudy forest at 2163 m a.s.l. (Fig. 17 ).

Etymology.

The new species is named for its type locality, Zham Town.

Figures

Figure 15. Distribution map of Laemostenus spp. L. zhentangensis sp. nov. (blue); L. zhamensis sp. nov. (red).

Figures 1, 2. Holotypes of Laemostenus spp. (general view and labels) 1 L. zhentangensis sp. nov. (male, Xizang, China, IZAS) 2 L. zhamensis sp. nov. (male, Xizang, China, IZAS).

Figures 3 - 8. Morphological features of Laemostenus spp. 3 - 5 L. zhentangensis sp. nov. 6 - 8 L. zhamensis sp. nov. 3, 6 head 4, 7 pronotum 5, 8 sutural angle of elytron.

Figures 9 - 14. Male genitalia of Laemostenus spp. 9 - 11 L. zhentangensis sp. nov. 12 - 14 L. zhamensis sp. nov. 9, 12 median lobe of aedeagus A dorsal view B left lateral view 10, 13 right paramere 11, 14 left paramere.

Figures 16, 17. Habitats in the type localities of Laemostenus spp. 16 Zangqiong, Zhentang Town, Dinggye County, Xigaze, Xizang, China; locality of L. zhentangensis sp. nov. 17 Nyalam County, 100 m below Zham Town, Xigaze, Xizang, China; locality of L. zhamensis sp. nov.