Behavior, biogeography and speciation: the curious case of the Nesobasis damselflies of Fiji

The Nesobasis damselflies, endemic to the Fiji Islands, offer a number of evolutionary puzzles. First, they are a very speciose group, with 21 described species and 14 more being described--a surprising level of diversity for an endemic island genus. Second, they show a broad range of morphological diversity, yet little in the way of ecological diversity; many species in the genus are found flying together in the same habitats. Finally, for some species, males are very difficult to find, while the males of other species are abundant along forested streams. Here we present phylogenetic and biogeographic analyses aimed at understanding the evolution of diversity in Nesobasis. While species of Nesobasis are distributed over a number of islands, two major groups exist: those species associated with the island of Viti Levu and those associated with Vanua Levu. The distribution of these species will be considered in light of phylogenetic relationships and the history of island development in the archipelago.