Seven new species of Gonioctena Chevrolat are described from the Oriental region and Palaearctic China: Gonioctena (Asiphytodecta) mausonensis sp. nov., G. (A.) oudai sp. nov., G. (Brachyphytodecta) arunensis sp. nov., G. (B.) mauroi sp. nov., G. (B.) medvedevi sp. nov., G. (Gonioctena) fujiana sp. nov. and G. (G.) mongolica sp. nov. Gonioctena (Asiphytodecta) subgeminata tonkinensis (Chen, 1934) is removed from synonymy with G. (A.) subgeminata (Chen, 1934) and raised to the species level. Gonioctena (Gonioctena) suwai Takizawa, 1985 is synonymized with G. (G.) ogloblini Medvedev & Dubeshko, 1972. Gonioctena (Asiphytodecta) sapaensis nom. nov. is proposed as a replacement name for G. (A.) unicolor Medvedev, 1987 not Phytodecta quinquepunctata var. unicolor Weise, 1884. Lectotype is designated for Phytodecta subgeminatus var. tonkinensis Chen, 1934.

An updated list of Chrysomelidae of Korea is provided with comments on all taxonomic, nomenclatural, and distributional changes. This paper is the first attempt to divide the distributional records of all Korean Chrysomelidae into records for North and South Korea. In total, 128 genera and 424 species are reported: 293 species in North Korea, 340 in South Korea, and 10 without precise localities in Korea; 22 species are excluded from the Korean fauna; 15 new national records from South Korea are reported, 10 of which are new to Korea.

The Gonioctena kanfani species-group of the nominotypical subgenus Gonioctena Chevrolat, 1836 is proposed and reviewed. This group comprises the following five species, including two new to science, distributed in eastern China and northern Laos: G. kanfani (Chen, 1941), G. kamikawai (Chûjô, 1958), G. fujiana Cho & Borowiec, 2016, G. jolantae new species, and G. lukasi new species. Members of this species-group are easily distinguished from other species by their metallic lustre, two yellowish-brown markings on the elytral humeri, and the trifurcated tip of the flagellum of the aedeagus. Photographs of habitus, illustrations of male genitalia, and diagnostic characters for each species are given. A distribution map and literature records are also provided.

This paper defines and reviews the Gonioctena subgeminata species group of the subgenus Asiphytodecta Chen, 1935. The group contains the following five species, including two new to science: G. subgeminata (Chen, 1934), G. tonkinensis (Chen, 1934), G. oudai Cho & Borowiec, 2016, G. allardisp. nov., and G. mantilleriisp. nov. The species group restricted to China and Vietnam is characterized by a labrum without a tooth-like projection, elytral punctures arranged in discernible rows, and a setose aedeagus with a broad apical process. Gonioctena tonkinensis is newly reported as an ovoviviparous species. Habitus photographs, illustrations of diagnostic characters of each species, and a key to the species are provided.

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