Title

Phylogenetic relationships of New Zealand cicadas

Date of Completion

January 2002

Keywords

Biology, Molecular|Biology, Entomology|Biology, Genetics

Degree

Ph.D.

Abstract

New Zealand cicadas, a group of nearly 40 species (some not yet described), are divided into 5 genera. They are endemic to New Zealand and to the surrounding “outer islands”: the Kermadec, Chatham, and Norfolk islands. Based on molecular sequence data from a variety of mitochondrial genes (COI, COII, 12S, 16S, ATPase6 and ATPase8) and a nuclear gene (EF1alpha), I examined (1) the phylogenetic relationships of the genera to each other and to closely related Australian and New Caledonian taxa, (2) the relationships of the “outer island” species to species on the New Zealand North and South Islands, (3) relationships within the most speciose genus, Kikihia. Two of the New Zealand genera (Amphipsalta and Notopsalta) were found to be derived from Australian taxa, while the other three genera (Kikihia, Maoricicada , and Rhodopsalta) had affinities with New Caledonian taxa. The timing of divergence between New Zealand, Australian, and New Caledonian taxa was estimated using a molecular clock. This divergence was estimated to have occurred within the last 12 million years. This result indicated that New Zealand must have been colonized from overseas via long distance dispersal. Long distance dispersal within the last 4.62 million years was also responsible for the colonization of the “outer islands” from New Zealand. Based on molecular sequence data two of these “outer island” cicadas, K. convicta and K. cutora exulis, were found to very closely related. This result questioned the taxonomy of the K. cutora subspecies group. The genus Kikihia was found to have evolved within the last 10 million years, with a species explosion 3–5 million years ago. The results of these phylogenetic analyses were compared with previously published hypotheses of New Zealand cicada relationships, and examined within the context of the well studied geological and climatological history of New Zealand. ^