Systematics, biogeography and conservation of the Pheidole roosevelti group (Hymenoptera: formicidae) in Fiji

This taxonomic revision treats the members of the Pheidole roosevelti group. The group is remarkable in the extreme modification of their propodeal spines, mesonotal shapes and head shapes. Seven species, all endemic to the Fiji Islands, are recognized: P. bula sp. n., P. colaensis Mann 1921, P. furcata sp. n., P. pegasus sp. n., P. roosevelti Mann 1921, P. simplispinosa sp. n., P. uncagena sp. n. Descriptions and diagnostic keys are provided for the minor, major and queen castes. All species are illustrated with digital images, and a map illustrates their geographic distributions across the Fijian archipelago. The group is compared to Pacific congeners with special attention given to species of the subgenus Pheidole (Pheidolacanthinus) F. Smith. A molecular phylogeny based on mitochondrial and nuclear genes is used to test hypotheses of relationship based on morphology, in addition to biogeographical patterns within Fiji and the Western Pacific.