This comprehensive study presents the prevalence of total visual impairment in the adult Japanese population. The projected increases in the prevalence of visual impairment over time reflect the demographic changes of a declining and aging Japanese population. These projections highlight that the burden of disease due to visual impairment and imposed on society is likely to increase.

Maternally inherited bacterial endosymbionts in arthropods manipulate host reproduction to increase the fitness of infected females. Cytoplasmic incompatibility (CI) is one such manipulation, in which uninfected females produce few or no offspring when they mate with infected males. To date, two bacterial endosymbionts, Wolbachia and Cardinium, have been reported as CI inducers. Only Wolbachia induces complete CI, which causes 100% offspring mortality in incompatible crosses. Here we report a third CI inducer that belongs to a unique clade of Alphaproteobacteria detected within the coconut beetle, Brontispa longissima. This beetle comprises two cryptic species, the Asian clade and the Pacific clade, which show incompatibility in hybrid crosses. Different bacterial endosymbionts, a unique clade of Alphaproteobacteria in the Pacific clade and Wolbachia in the Asian clade, induced bidirectional CI between hosts. The former induced complete CI (100% mortality), whereas the latter induced partial CI (70% mortality). Illumina MiSeq sequencing and denaturing gradient gel electrophoresis patterns showed that the predominant bacterium detected in the Pacific clade of B. longissima was this unique clade of Alphaproteobacteria alone, indicating that this endosymbiont was responsible for the complete CI. Sex distortion did not occur in any of the tested crosses. The 1,160 bp of 16S rRNA gene sequence obtained for this endosymbiont had only 89.3% identity with that of Wolbachia, indicating that it can be recognized as a distinct species. We discuss the potential use of this bacterium as a biological control agent.

The beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae) is a serious invasive pest of the coconut palm, Cocos nucifera I., in Southeast Asia and the Pacific region. Genetic analysis is essential to ecological and evolutionary study of such invasive species. We therefore conducted molecular analyses by using partial sequences (1044 bp) of the mitochondrial cytochrome oxidase subunit I (COI) genes of B. longissima collected from several locations. We found two monophyletic groups: one distributed over a limited area (Australia, Papua New Guinea, Samoa, and Sumba Island; referred to as the Pacific group) and the other collected from a wide area of Asia and the Pacific region (referred to as the Asian group). We compared the biological and morphological traits of the two groups. We found that insects in the Pacific group had a shorter developmental time from hatching to adult emergence, produced fewer eggs, and had a larger adult body size than insects in the Asian group. Elytral color patterns did not differ between the two groups. Our interpopulation crosses produced significantly fewer progeny than intrapopulation crosses, suggesting that B. longissima represents two cryptic species.

The coconut hispine beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae) is considered native to Indonesia and Papua New Guinea, and it has been established and causing serious leaf damages on Cocos nucifera (L.) in Asia, Australia and the Pacific Islands. Although this insect was found on only C. nucifera in the Yaeyama Islands, Japan in the 1980s, it was unknown whether it had established in the islands and whether it attacked the endemic palm Satakentia liukiuensis (Hatusima) H. E. Moore. We conducted field surveys in the Yaeyama Islands in 2007 to 2009 to determine whether B. longissima causes serious damages on S. liukiuensis in the islands. Although B. longissima infested leaves of the young trees in most nurseries or roadsides on Ishigaki, Iriomote and Kohama islands, no serious damage was observed on wild mature trees of the S. liukiuensis communities, which are protected as national natural monuments. All the developmental stages of B. longissima were found in November 2008 and May 2009. The present study first shows that B. longissima is common and attacks the endemic palm S. liukiuensis as a main host in the Yaeyama Islands where C. nucifera is very rare.

No abstract