Molecular phylogeny of moss-inhabiting flea beetles from the Chabria group (Coleoptera: Chrysomelidae: Alticini) reveals multiple colonizations and radiations in Taiwan

Moss-inhabiting flea beetles form a very diverse and understudied ecological group of leaf beetles (Coleoptera: Chrysomelidae) characterized by cryptic lifestyle, loss of flight ability and feeding on mosses as both adults and larvae. We present the first DNA-based study of the phylogenetic position of moss-inhabiting flea beetle genera Ivalia Jacoby and Cangshanaltica Konstantinov et al., based on sequences of two mitochondrial and three nuclear genes. We confirm that both genera are members of the monophyletic Chabria group, along with Chabria Jacoby, Parathrylea Duvivier, Chabriosoma Chen and Sutrea Baly. Moss-inhabiting species form at least three independent lineages within the Chabria group, indicating multiple parallel origin of the association with mosses within the clade. We reveal the monophyly of Cangshanaltica and confirm its separate generic status from Ivalia. Ivalia is revealed as polyphyletic, consisting of at least two unrelated moss-inhabiting lineages. In contrast, the externally similar moss- and leaf-litter inhabiting genera Mniophila Stephens, Adamastoraltica Biondi et al. and Clavicornaltica Scherer are not closely related to the Chabria group. Our study specifically focused on the moss-inhabiting flea beetles of Taiwan. We reveal that the Taiwanese fauna is a result of four independent colonizations of the island: one from China (Cangshanaltica) and three from the Philippines (three lineages morphologically assigned to Ivalia). Two of these lineages (Cangshanaltica and the core Ivalia) radiated in Taiwan and gave rise to the majority of modern Taiwanese species. The evolutionary history of Cangshanaltica and its diversification in China are also discussed.