Revision of Taiwanese species of Atrachya Chevrolat, 1836 (Coleoptera, Chrysomelidae, Galerucinae): descriptions of three new genera, two new species, and designations of three new synonyms.

The genus Atrachya Chevrolat is redefined based on study of the type species A. menetriesii (Faldermann, 1835). All Taiwanese species of Atrachya are transferred to three new genera: A. hirashimai Kimoto, 1976 and A. nitidissima (Chûjô, 1935) are transferred to Neochya gen. nov.; A. mediofasciata Kimoto, 1976 is transferred to Tsouchya gen. nov.; A. unifasciata Takizawa, 1978 is transferred to Chinochya gen. nov. Two species are described: N. chengi sp. nov. and N. tsoui sp. nov. Atrachya bicoloripennis (Chûjô, 1938) and A. saramao (Chûjô, 1962) are regarded as synonyms of N. nitidissima (Chûjô, 1935) comb. nov., and Monolepta tsoui Lee, 2009 is synonymized with T. mediofasciata (Kimoto, 1976) comb. nov. Monolepta sublata Gressitt & Kimoto, 1963 is redescribed and transferred to Chinochya gen. nov. Taiwanese records of Monolepta sublata are based on misidentifications and represent specimens of C. unifasciata. Variablity of adult color patterns is discussed.