Dianous vietnamensis Puthz, 1980

(Figs. 1, 7, 13, 23, 29)

Dianous vietnamensis Puthz, 1980: 234; Puthz, 2000: 452; Puthz, 2016: 751.

Material examined. China: Guangxi: 42♂♂ 44♀♀, Jingxi County, Tonglinxiagu, 25.VII.2006, Li-Zhen Li leg. (SHNU); 7♂♂ 12♀♀, Shangsi County, Shiwandashan, alt. 300–400m, Peng, Zhai & Zhu leg. (SHNU) ; Yunnan: 24♂♂ 26♀♀, Xishuangbanna, Nabanhe N. R., Nabancun, alt. 700m, 26.VII.2005, Li & Li leg. (SHNU) ; Hainan: 11♂♂ 24♀♀, Linshui County, Diaoluoshan, alt. 900m, 18.XI.2006, Li leg. (SHNU) ; 1♂, Changjiang County, Bawangling, alt. 1000m, 13.IV.2010, Feng & Yuan leg. (SHNU) ; 1♂ 1♀, Ledong County, Jianfengling, alt. 900 m, 16.IV.2010, Feng & Yuan leg. (SHNU) ; 18♂♂ 24♀♀, Linshui County, Diaoluoshan, alt. 930–1000m, 21–23.IV.2010, Yuan & Feng leg. (SHNU) ; 4♂♂ 2♀♀, Ledong County, Jianfengling, 800 m, 17.V.2011, Wen-Xuan Bi leg. (SHNU) ; 3♂♂ 3♀♀, Baishan County, Yuanmenxiang, Yinggezui, 600 m, 26.IV.2011, Wen-Xuan Bi leg. (SHNU) ; 1♂ 1♀, Wuzhishan, 700 m, 04.II.2012, He & Tang leg. (SHNU) ; 11♂♂ 10♀♀, Wuzhishan, Guanshandian, 18°53′N, 109°41′E, 650 m, 19.IV.2012, Dai & Peng leg. (SHNU) ; 120♂♂ 146♀♀, Wuzhishan, 18°54′N, 109°41′E, alt. 650–700 m, 18–21.IV.2012, Peng, Dai, Yin, Li & Pan leg. (SHNU) ; 6♂♂ 6♀♀, Linshui County, Diaoluoshan, 18°43′N, 109°51′E, alt. 1000 m, 24.IV.2012, Dai & Peng leg. (SHNU) ; 1♂ 1♀, Linshui County, Diaoluoshan, Shuiku, 18°43′N, 109°53′E, alt. 950–1000 m, 25.IV.2012, Dai & Peng leg. (SHNU) ; 4♂♂ 6♀♀, Ledong County, Jianfengling, 18°44′N, 108°50′E, alt. 900 m, 2.V.2012, Dai & Peng leg. (SHNU)

Measurements. BL: 3.9–4.7 mm, FL: 2.4–2.7 mm. HW: 0.88–0.97 mm, PL: 0.74–0.80 mm, PW: 0.74–0.82 mm, EL: 1.11–1.23 mm, EW: 1.11–1.25 mm, SL: 0.96–1.06 mm. Head 0.74–0.80 times as wide as elytra, pronotum 0.95–1.00 times as long as wide, elytra 0.97–1.01 times as long as wide.

Distribution. China (Yunnan, Guangxi, Hainan), Vietnam, Laos.

Remarks. The species is similar to D. rougemontianus Puthz, 2000 from Sichuan and Hubei, D. ruginosus Zheng, 1993 from Sichuan, and D. aerator Puthz, 2016 widely distributed in China, but can be easily distinguished from them by body with blue metallic tinge and smaller ratio of HW/EW. The species is new to Guangxi.