Gonioctena (Asiphytodecta) tonkinensis (Chen, 1934) stat. nov.

(Figs 7–8, 28–30)

Phytodecta subgeminatus var. tonkinensis Chen, 1934: 76 (type locality: Tonkin); Chen 1938: 294; Kimoto & Gressitt 1981: 386 (as synonym of G. subgeminata); Kippenberg 2010: 432 (as synonym of G. subgeminata).

Phytodecta (Asiphytodecta) subgeminatus var. tonkinensis: Chen 1935: 131; Chen 1936: 88.

Gonioctena (Asiphytodecta) subgeminata tonkinensis: Gressitt & Kimoto 1963: 360 .

Phytodecta subgeminatus tonkinensis: Chen & Young 1941: 208 .

Types. Lectotype: female (ZMHB), here designated to fix the concept of Gonioctena tonkinensis and to ensure the universal and consistent interpretation of the same, Tonkin, Montes Mauson, April, Mai 2 -3000′, H. Fruhstorfer // Type // TYPE // Phytodecta subgeminata Chen // LECTOTYPUS Phytodecta subgeminata var. tonkinensis Chen, 1934 des. H.W. Cho 2015. Paralectotype: 1 male (ZMHB), same data as lectotype.

Additional material. 1 male (NMPC), Vietnam bor. Tam-Dao, 27.V.–2.VI.1986, J. Macek lgt.; 1 female (NMPC), China, Guangxi A.R., 11.–14.IV.2013, Longsheng Hot Spring (forested river valley, wet rocks), 25°53.6'N, 110°12.4'E, 360 m, M. Fikáček, J. Hájek, J. Růžička leg.; 1 male (LMCM), N. Vietnam (Tonkin), TamDao, 12.–24.V.1989, Pacholatko leg.; 1 male and 1 female (LMCM), Vietnam, Prov. Vinh-Phu, Tam-dao, L. Medvedev @ Dang Dap // on Ormosia (Fab.) .

Distribution. China (Guangxi), Vietnam (Vinh Phuc).

Note. Gonioctena subgeminata tonkinensis (Chen, 1934) was synonymized with Gonioctena subgeminata (Chen, 1934) by Kimoto & Gressitt (1981), however they did not examine any specimens of both species and subspecies. We examined the types of G. subgeminata tonkinensis and specimens which perfectly fit the original description of G. subgeminata, and found that they are two distinct species. Gonioctena subgeminata tonkinensis can be distinguished easily by a pair of basal triangular black markings on pronotum (Fig. 8) (without spots in G. subgeminata, Fig. 6), 2 black spots and 2 sinuate transverse bands on elytra (Fig. 7) (11 black spots in G. subgeminata, Fig. 5) and long and thin aedeagus with blunt apex (Fig. 29) (thick aedeagus with widely rounded apex in G. s u b g e m i n a t a, Fig. 31). Therefore, Gonioctena subgeminata tonkinensis is removed from synonymy with G. subgeminata and raised to the species level.