Phylogeny and divergence time of island tiger beetles of the genus Cylindera (Coleoptera: Cicindelidae) in East Asia

Abstract

To examine the diverse colonization histories in eight tiger beetle species of the genus Cylindera (Coleoptera: Cicindelidae) on the East Asian islands, we conducted phylogenetic analyses and divergence time estimation using mitochondrial cytochome oxidase subunit I (COI) and nuclear 28S rDNA sequences. The island fauna consisted of four subgenera: Apterodela, Cicindina, Ifasina, and Cylindera. Apterodela is a flightless group with large bodies, whereas the others are fliers with small bodies. In Apterodela, the divergence among endemic species in Taiwan, Japan, and the mainland was ancient (2.1-4.7Mya), as expected from their flightlessness. Their dispersal might have occurred across the extended landmass in East Asia during the Pliocene. In the subgenus Cicindina, Cylindera elisae has spread throughout East Asia, from which an endemic species, Cylindera bonina, was derived on the oceanic Bonin Islands during the early Pleistocene (0.9Mya). This indicates the significance of Cylindera bonina, which is currently confined to a single island, for conservation. In the subgenus Ifasina, Cylindera kaleea is widely distributed in East Asia, and its sister species Cylindera humerula, endemic to Okinawa Island, diverged 1.0Mya, whereas Cylindera psilica on Taiwan and the Yaeyama Islands diverged approximately 0.8Mya. In the subgenus Cylindera, the colonization of Cylindera gracilis in Japan from the mainland occurred during the last glacial period. With the exception of C. bonina, which likely colonized new territories by flight or drifting, other dispersal events might have used land connections that occurred repeatedly during the Pliocene and Pleistocene.© 2011 The Linnean Society of London.