Female. Internal organ of reproductive system (Fig. 4d). Vagina elongate, with median oviduct situated at ventro-apical part, vagina abruptly narrowed in apical part and extended into a long tube from where diverticulum and spermathecal duct are arising; diverticulum long, 0.3 times as long as adult body length, evenly thinned apically, slender tube-shaped and spiral; spermathecal duct 0.2 times as long as diverticulum; spermatheca slender tube-shaped and spiral, thinner than spermathecal duct and 1.1 times longer than diverticulum, with basal part extended into a short tube, at opening of accessory gland. Accessory gland thin in basal part and the remainder relatively thick, 0.8 times as long as spermatheca.
Description. Male (Fig. 8). Head black, reddish brown on middle line of vertex, mouthparts light yellow, more or less darkened at maxillary and labial palpi, dark brown at apices of mandibles, antennae black, light yellow at apex of each antennomere, pronotum light yellow, with a large dark brown marking on disc, scutellum light yellow, elytra light yellow and mottled with irregular dark brown markings, legs light yellow, black at bases of coxae and tibiae and apices of femora and tarsomeres, more or less darkened at outer sides of femora and outer and dorsal sides of tibiae, prosternum light yellow, meso- and metasterna and abdominal ventrites dark brown, light yellow at posterior margins of abdominal ventrites and the whole terminal ventrite. Body densely covered with light yellow pubescence, sparsely mixed with slightly long, semirecumbent light yellow pubescence and erect black brown setae on elytra. Head subquadrate, temples straight and slightly converging posteriorly, dorsum distinctly convex in central part, surface semilustrous, densely and finely punctate, each side with a smooth and rectangular impression behind antennal socket; eyes strongly protruding, head width across eyes distinctly narrower than pronotum; terminal maxillary palpomeres long-triangular, widest at basal one-third, with apical parts of inner margins arcuate and sharp, acute at apices; antennae extending to basal two-thirds length of elytra, antennomeres II about twice as long as wide at apices, III slightly longer than II, IV longest, from V to XI gradually shortened, XI pointed at apex. Pronotum about 1.30 times as wide as long, widest nearly in middle, anterior margin rounded, lateral margins rounded, posterior margin nearly straight and narrowly bordered, anterior angles rounded, posterior angles sharp, protruding, disc distinctly convex on posterolateral parts, surface semilustrous, finely and sparsely punctate. Elytral length about 5 times length of pronotum, 3 times as long as humeral width, with lateral margins slightly diverging posteriorly, surface semilustrous, rugulose-lacunose and finely punctate. Aedeagus (Figs. 39 ‒ 41): ventral process of each paramere bent ventrally about 60 degrees, with the bent portion at apical part distinctly shorter than the basal part, slightly thickened terminally and circular at apex in lateral view, dorsal plate distinctly shorter than ventral process, abruptly narrowed apically, narrowly rounded at apex; laterophyse rounded at apex. Female. Similar to males, but head slightly convex on dorsum, antennae shorter and extending to elytral midlength, pronotum moderately convex on posterolateral parts of disc, lateral margins distinctly diverging posteriorly, abdominal sternite VIII (Fig. 20) abruptly narrowed posteriorly, nearly parallel-sided on posterior part, longitudinally convex on middle sclerotized part, the convex global at anterior portion and nearly parallel-sided at posterior portion, with lateral margins slightly sclerotized at posterior part and moderately sclerotized at anterior part, posterior margin roundly emarginated in middle, lateroapical angles triangular, the lobe moderately sclerotized, triangular and acute at apex. Body length: 7.0 ‒ 9.0 mm; width: 1.5 ‒ 1.8 mm.
Diagnosis. This species is similar to S. leishanensis sp. nov., but can be distinguished by the pronotum distinctly wider than long; aedeagus: ventral processes of parameres slightly thickened terminally and circular at apex in lateral view.
Remarks. The left antennomeres IX ‒ XI, left metatarsomeres II ‒ V and right middle leg of the holotype are missing. The head, thorax and abdomen of the male paratype are separated but adhered, and the right antennomeres X ‒ XI, right mesotarsomeres IV ‒ V and hind legs are missing.
Distribution. China (Xizang).
Etymology. The specific name is derived from Latin latus (broad) and collum (neck), referring to its pronotum, which is distinctly wider than long.
Type material. Holotype ♂ (IZAS): CHINA: Xizang, Nyingchi, Pêlong, 2100 m, 1. IX. 2005, leg. X. L. Chen. Paratypes: 8 ♀♀ (IZAS): same data as holotype; 1 ♂, 3 ♀♀ (MHBU): same locality, 23. ‒ 28. IX. 2007, leg. F. M. Shi. [all transliterated from Chinese labels].