Suitability of four palm species for the development of the invasive pest Brontispa longissima (Coleoptera: Chrysomelidae) in the field

The coconut hispine beetle Brontispa longissima (Gestro) supposedly originated in Indonesia and Papua New Guinea. It is a serious invasive pest of the coconut palm Cocos nuciferaL. in Southeast and East Asia. In Japan, it has established itself using Satakentia liukiuensis (Hatushima) H.E. Moore as a main host on Ishigaki and Iriomote Islands where C.nucifera is rare. To assess the probability of further establishment of B.longissima in novel habitats where C.nucifera and S.liukiuensis are not available, we examined the suitability of four common palm species in Japan for oviposition and immature development of B.longissima: Chrysalidocarpus lutescens (Bory) H. Wendl., Phoenix roebeleniiO'Brien, S.liukiuensis and Washingtonia filifera (Linden ex Andre) H. Wendl. When seedlings of the four palm species were placed in pots in an experimental field on Ishigaki Island, all four species were inhabited and infested by wild B.longissima adults. Oviposition and immature development were observed on P.roebelenii and S.liukiuensis but not on C.lutescens and W.filifera. When field-collected adults were released into mesh bags enclosing the potted seedlings, they oviposited on all four species. The eggs developed into adults on P.roebelenii, S.liukiuensis and W.filifera. On C.lutescens, however, hatched larvae died during the first or second instar.