Grouvellinus nujiangensis sp. nov.

(Figs 4A–B, 11A–C, 16A–C)

Type material examined: holotype, male (IAECAS): “ China: Yunnan (30) / Nujiang Pref./ Fugong County / Shiyueliang Townļ 27°14′2″N 98°53′25″E / 1074 m, 2019.7.8 / Leg. Peng & Dong. Paratypes: 2 males, 1 female (IAECAS), the same data as holotype; 1 male (IAECAS): “ China: Yunnan / Yingjiang Pref. / Nabang Town ļ 24°37.38′N 97°37.48″E ” / 1478 m / 26. VI. 2019 / Leg. Peng et al. (6); 1 ex. (IAECAS): “ China: Yunnan / Tengchong City / Jietou Vill. ļ 25°31′14″N 98°33′49″E / 1910 m, 30.VI. 2019 / Leg. Peng & Dong (14)”; 1 male (IAECAS): “ China: Yunnan / Tengchong, Mingguang / Zhongtang Vill. ļ 25°26′2″N 98°31′16″E / 1823 m, 30.VI. 2019 / Leg. Peng & Dong (16)”; 1 ex (NHMW).: “China: Yunnan, Xishuangbanna / ca. 15 km W Menglun / 5.11.1999, ca. 700- 800 m / leg. Jäch et al. (CWBS 354)”; 4 exs. (NHMW): “ CHINA: Yunnan, Xishuangbanna / ca. 10 km NW Menglun / 7.11.1999, ca 700 m / leg. Jäch et al. (CWBS 359)”; 20 exs. (NHMW): “ CHINA: Yunnan, Xishaungbanna / pass betw Jinghong, Mengyang / 12.11.1999, ca. 1100 m / leg. Jäch et al. (CWBS 379)”; 1 ex. (NHMW): “ CHINA: Yunnan, Xishuangbanna / ca. 10 km NW Menglun / 7.11.1999, ca. 700-800 m / leg. Jäch et al. (CWBS 380)”; 2 exs. (NHMW): “China: Yunnan, Simiao Pref. / 40 km S Simiao, 16.11.1999 / Caiyang River, NR, ca. 135 m / Schönmann & Wang (CWBS 389); 1 ex. (NHMW): “ CHINA: Yunnan, Chuxiong Pref. / Da Shui go riv. Ban Jiu / 10 km N Yiping lang / 27.11.1999, ca. 1700 m / Schönmann & Wang (CWBS 409) .

Diagnosis. Body broadly obovate, 2.2–2.3 mm long, dorsum black; disc of pronotum without carina or sulcus, sublateral carina present in basal 0.3 on pronotum; elytra distinctly attenuated in distal half; strial punctures small in basal half, smaller in distal half; elytral intervals 7, 8 carinate; prosternal process is subquadrate. This species can be distinguished from Grouvellinus spnaericus sp. nov. and G. elongatus sp. nov. which also with broad body by its smaller body size, by its distal half of elytra distinctly attenuated, by its paramere with an indention in basal half, and also by distal third of parameres distinctly narrowed.

Description. BL 2.3 mm, BW 1.2 mm. Body broadly obovate, habitus see Figs 4A–B. Dorsum black, antennae yellowish brown. Legs light brown. Ventral side brown to dark brown.

Head. Labrum smooth and shining, sparsely punctate and pubescent, anterior margin densely pubescent laterally. Clypeus and frons smooth and shining, pubescence denser than on labrum.

Pronotum (Fig. 11A). PL 0.7 mm, PW 0.9 mm, broadest at basal 0.4, distinctly attenuated anteriorly and slightly attenuated posteriorly. Disc distinctly convex, densely punctate and pubescent. The pubescence short and semierected. Median carina absent. Sublateral carinae present in basal 0.3, a shallow groove extending from apex of the carina towards anterior angle on each side.

EL 1.6 mm, EW 1.2 mm. Elytra subparallel in basal 1/2, distinctly attenuated in distal half. Strial punctures small, separated by 2–3 times of their diameters in basal half, then smaller and well separated in distal half. Intervals convex, sparsely punctate, with a row of pubescence on intervals 1, 3, 5. Intervals 7, 8 carinate.

Prosternal process (Fig. 11B) is subquadrate, with lateral sides almost subparallel, lateral margin distinctly rimmed, disc sparsely punctate and pubescent, apex broadly cambered. Metaventrite (Fig. 11C) slightly and broadly impressed, disc sparsely pubescent and punctate; lateral area densely pubescent. A row of large punctures behind of mesocoxa, and a row of small punctures in front of metacoxa.

Disc of ventrites I–IV smooth and shining, sparsely punctate and pubescent, and the lateral area densely pubescent. Disc of ventrite V smooth and shining in basal half, and the other area densely pubescent and granulate (Fig. 11C).

Aedeagus (Figs 16A–C). 0.6 mm long. Penis slightly longer than phallobase. Penis is broad in basal half, gradually narrowed in distal half. Paramere with a big indention in basal half, distal half broad, apex broadly rounded.

Males: BL 2.2–2.3 mm, BW 1.1–1.2 mm (n=4); females: BL 2.0– 2.4 mm, BW 1.1 mm (n=2).

Distribution. China: Yunnan.

Etymology. This species is named after Nujiang autonomous prefecture in Yunnan Province.