The long-horned beetle family Cerambycidae is one of the largest. But despite its popularity amongst entomologists relatively little is known about the Fijian taxa. A survey by Dillon & Dillon (1952) recorded 120 species in Fiji of which approximately 98% are unknown elsewhere. In addition to the unique character of the Fijian cerambycid fauna overall it also contains the world’s second largest beetle. Xixuthrus heros can grow to ~15cm in length, however little else is known about this rare and possibly endangered endemic.
Based on morphology Dillon & Dillon (1952) produced a taxonomic key to the Fijian Cerambycidae. However, evolutionary relationships among the species have not yet been investigated. This is one focus of my PhD. project. A molecular phylogeny for the group in Fiji would contribute to a better understanding of the origins and evolutionary patterns within Fiji, as well as how the Fijian species relate to others in the Pacific and the family as a whole. A second goal of the project is to explore the host-specificity of Fijian cerambycids. A preliminary study in Papua New Guinea has shown a high degree of host-specificity in the larval stages of the long-horned beetle life cycle. Understanding host-specificity in the Fijian taxa would provide a useful comparison but in combination with the phylogeny may help us to better understand the processes underlying diversification of Fijian long-horned beetles.
Results of this study will provide vital information on the taxonomy, phylogeny, and host-specificity of Fijian Cerambycidae. This information will also have practical value; based on an understanding of host-specificity it may be possible to use plant species richness as a bioindicator of cerambycid diversity in an area. This would further contribute to the conservation of this unique but understudied group.
Dr. Richard Winkworth (USP), Dr Steve Trewick (Massey University, NZ), and Dr. Steve Lingafelter (Smithsonian Institute, USA).