New species and new records of leaf beetles (Coleoptera: Chrysomelidae) from Thailand and Vietnam

Eight new species of leaf beetles are described from Thailand and Vietnam: Charaea khuntanensis sp. n., Japonitata insolita sp. n., Monolepta quadrifoveolata sp. n., Monolepta trizonalis sp. n., Paleosepharia pseudorubricollis sp. n., Strobiderus excavatipennis sp. n., Eudolia doisaketensis sp. n., and Phygasia oblongomaculata sp. n. The following 13 species are recorded from Thailand for the first time: Lema impressipennis Pic, 1944, Cryptocephalus flavicinctus Jacoby, 1892, Trichochrysea cephalotes (Lefèvre, 1893), Apophylia borowieci Bezděk, 2004, Apophylia clypeata Samoderzhenkov, 1988, Atysa brevicornis (Samoderzhenkov, 1988), A. gressitti (L. Medvedev, 2005), Paridea glyphea Yang, 1993, Chaetocnema yunnanica Heikertinger, 1951, Hyphasis trilineata L. Medvedev, 2008, Philopona shima Maulik, 1928, Yunotrichia mediovittata Chen et Wang, 1980, and Cassida rati Maulik, 1923. Figures of habitus and genitalia are given for all new for science and some related species, as well as for some of newly recorded species. The male habitus and the aedeagus of Atysa brevicornis previously known only from females are imaged for the first time. New morphological data on the rare species Sinoluperoides chenchirae Romantsov, 2025 and Paleosepharia magnitarsis Romantsov, 2025 are presented. An auxiliary identification key to the Phygasia Chevrolat, 1836 species with black body and a pale spot on each elytron is compiled.