Quaternary donaciine beetles (Coleoptera, Chrysomelidae) in Japan: Colonization and divergence patterns inferred from fossil and molecular data

Abstract

We review the current knowledge of the distribution, ecology, fossils, and molecular phylogeny of donaciine beetles in Japan and its adjacent regions, and discuss historical faunal change on the Japanese islands during the Quaternary. The present Japanese fauna consists of 23 species within the genera Donacia, Plateumaris, and Macroplea, nine of which are endemic to Japan. Five fossil species have been found in strata from the Late Miocene to the Middle Pleistocene; the fossil species became extinct by the Middle Pleistocene. The oldest fossils of the extant species are of two endemic species Plateumaris akiensis and P. constricticollis from the Pliocene. P. akiensis is currently confined to a single locality, whereas P. constricticollis occurs over a wide geographic range and shows marked morphological and genetic divergence. Early Pleistocene fossils of the endemic species Donacia japana and D. ozensis, and the non-endemic Donacia vulgaris have been found. Middle Pleistocene fossils of non-endemic species such as Plateumaris sericea and D. splendens have been found, suggesting their colonization of Japan during this period. Mitochondrial COI gene sequences indicate that the haplotype coalescence times date back to the Middle–Late Pleistocene in most extant species, suggesting the occurrence of colonization and/or bottleneck events during this period. Exceptionally, P. constricticollis shows a Pliocene coalescence coincident with fossil records. In addition, P. sericea likely colonized Hokkaido and Honshu/Kyushu separately during the Middle Pleistocene following the divergence of two different haplotype lineages during the Early Pleistocene.