Genetic variation of the green chafer, Anomala albopilosa (Hope) (Coleoptera: Scarabaeidae), in the Ryukyu Islands of Japan detected by mitochondrial DNA sequences

In the Ryukyu Islands of Japan, larvae of the green chafer Anomala albopilosa (Hope) are known as a serious pest of sugarcane. Based on sequences of mitochondrial ribosomal RNA genes obtained from specimens collected in this and adjacent areas, the phylogenetic relationships among local populations and geographic distribution patterns of haplotypic groups were examined. As a result, individuals were divided into five groups of haplotypes (Groups A-E). The shape of the phylogenetic trees suggested that they have been separated for a long period in their evolutionary history. Among the three groups distributed in the Ryukyu Islands, Groups B and D were restricted to the northern Amami region and Yaeyama region, respectively, while the range of Group C extended from the Amami to Yaeyama regions through the Okinawa and Miyako regions and largely overlapped the other two groups. This result was considered to suggest that the insular populations of this species were genetically muddled by the recent expansion of Group C that probably originated in the Okinawa region in the central Ryukyu Islands. Causes of these phenomena are discussed in relation to the food habits of this species and the paleogeography of this area.