Weevils in the genus Rhyncogonus occur exclusively on oceanic islands in the Pacific, with a distribution that extends northwestwards from Pitcairn Island to Hawaii and Wake Island. All but one of the 127 described species in the genus are restricted to single islands, though multiple species often occur on any one island. Molecular sequence data and phylogenetic methods can be used to gain an insight into the direction and patterns of island colonisation and speciation seen within the genus. Preliminary results are presented here for species collected from the Marquesas and Society Islands. A phylogeny was derived from 453 b.p. of the cytochrome oxidase 1 mitochondrial gene region. The most parsimonious topology for this data set indicates that Marquesan and Society Islands weevils are quite distinct. The high levels of divergence between specimens from different archipelagos (>15% divergent in all cases) implies that the genus has a long history in the Pacific, this is supported by the observation that multiple species have been described from the oldest islands in the Hawaiian and Marquesan chains. Within the Society Islands the geographic location and phylogenetic relationship of specimens is consistent with the chronological age of the islands, though further sampling of the weevils in the Societies is necessary to verify this. On the basis of this preliminary work further study and sampling of the weevil diversity from these and other Pacific archipelagos would seem extremely worthwhile.
Species 1: Coleoptera Curculionidae Rhyncogonus
Keywords: weevil, colonisation
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA