Revision of the chrysomeline genera Potaninia, Suinzona and Taipinus (Coleoptera) from eastern Asia, with a biogeographic scenario for the Hengduan mountain region in south‐western China

The eastern Asian leaf beetle genera Potaninia Weise, Taipinus Lopatin and Suinzona Chen (Entomoscelina) are revised. A cladistic analysis, a key to the species, a generic redescription, descriptions of new species and distributional records are provided. The analysis of 44 exoskeletal and genitalic characters and one character of the altitudinal distribution suggests a clade comprising all three genera, a clade including Suinzona and Taipinus, the monophyly of the latter genus and a clade comprising 20 species of Suinzona occurring in high altitudes in the Hengduan Mountain region. The three species of Suinzona occurring at lower altitudes (S. yunnana, S. laboissierei and S. monticola) are isolated from this successful lineage. The strict consensus tree of the initial analysis is not well resolved, but only one tree was obtained after applying the successive reweighting option (in paup). This analysis suggests that Taipinus may be nested within Suinzona, which would imply paraphyly of the latter genus as it is presently defined. Nevertheless, considering the results of the initial analysis and the apparent instability of the phylogenetic results based on morphological data alone, we decided to maintain the generic rank of Taipinus at this stage. Eighteen new species from China are described and illustrated: Suinzona bergealisp.n., Suinzona bienkowskii sp.n., Suinzona chenisp.n., Suinzona cuiaesp.n.,Suinzona faldermannisp.n., Suinzona geblerisp.n., Suinzona jacobsonisp.n., Suinzona konstantinovisp.n., Suinzona lopatinisp.n., Suinzona medvedevisp.n., Suinzona menetriesisp.n., Suinzona mikhailovisp.n., Suinzona motschulskyisp.n., Suinzona ogloblinisp.n., Suinzona pallasisp.n., Taipinus convexussp.n., Taipinus elatussp.n. and Taipinus globosussp.n. Six described species are transferred from Oreomela Jacobson to Suinzona Chen: Suinzona belousovi (Lopatin) comb.n., Suinzona potanini (Lopatin) comb.n., Suinzona parva (Lopatin) comb.n., Suinzona wangi (Lopatin) comb.n., Suinzona yangi (Lopatin) comb.n. and Suinzona yunnana (Lopatin) comb.n. A biogeographic scenario for the genera is discussed. Whereas S. yunnana, S. laboissierei, S. monticola and the species of Taipinus are restricted to relatively low mountains, a major radiation of a clade within Suinzona took place in the Hengduan Mountain region above 3300 m a.s.l., which is presently the centre of diversity of the genus. These species are flightless and show a preference for scree slopes and rock crevices.