Stomis dilaticollis, Sciaky, 2024

Sciaky, Riccardo, 2024, Review of the Chinese Stomis, with description of nine new taxa and a new key (Carabidae: Pterostichini), Zootaxa 5523 (1), pp. 1-34 : 17-18

Stomis dilaticollis sp. nov.

https://zoobank.org/eb164bac-a09a-49b7-aae5-79676a87194a

Diagnosis. A Stomis of short length (8.2 mm) black, rather dull, convex. Head small, with markedly reduced eyes, pronotum almost as long as broad, with base sparsely punctate, elytra rather short and broad, with rounded shoulders and striae deep and punctate. Aedeagus small, depressed in the apical portion, with very short apical lamella.

Description. Habitus as in Fig. 23 . Length 8.2 mm; integuments rather shiny, black, body rather convex; legs and antennae dark reddish-brown, rather short; tarsi paler; head of medium size, with shallow collar constriction right behind the eyes; mandibles rather long, longer than the rest of the head; the right one without notch; eyes very small and flat; antennae relatively long, reaching the elytral base with the 7th article. Pronotum almost as broad as long, rather convex at sides; lateral margins markedly dilated in the anterior half, strongly and linearly constricted in regular curve towards the base; anterior margin advanced at middle; anterior angles projecting forward, very small; base almost straight; basal foveae well defined, linear, sparsely punctate; basal angles obtuse; lateral gutter very narrow all along. Elytra oval, very feebly dilated in the posterior half, all striae deep and evidently but finely punctate, intervals feebly convex; shoulders not constricted, rounded, without tooth. Median lobe of aedeagus in lateral view slightly but regularly curved downwards; in dorsal view with apical lamella very short and blunt ( Fig. 47 ). Ratios: El/Pl = 2.20; Ew/Pw = 1.37; El/Ew = 1.52.

Type-locality: China, China, Yunnan, pass 50 km N Qiaojia, 2850–3000 m.

Type-series. Holotype ♂: China, Yunnan, pass 50 km N Qiaojia , 2850–3000 m, 13–15.VII.2010, S. Murzin leg. ( CW).

Etymology. This specific epithet derives from the Latin and means “dilated neck”, with reference to the pronotum markedly dilated anteriorly.

Affinities. This species certainly belongs to the S. robustus -group, within which it seems to show some affinities with S. robustus . It can be distinguished from the latter by the much smaller size, shorter head and mandibles, less dilated elytra and pronotum less dilated anteriorly.

Distribution. Known from a single locality in Northern Yunnan, near the border of Sichuan.

Figures

FIGURES 21–24. Habitus of: (21) S. bousqueti HT (8.1 mm); (22) S. magrinii HT (10.1 mm); (23) S. dilaticollis HT (8.2 mm); (24) S. jani HT (10.2 mm).

FIGURES 43–47. Aedeagus in lateral and dorsal view of: (43) S. robustus HT; (44) S. schoenmanni from Yunnan, Ailao Shan; (45) S. bousqueti HT; (46) S. magrinii HT; (47) S. dilaticollis HT.