A systematic revision of the Macropsinae (Hemiptera: Cicadellidae) leafhoppers of Australia

In this systematic revision of the genera of Macropsinae (Cicadellidae: Hemiptera) of Australia, a particular focus was to determine whether the two largest genera in the subfamily, Macropsis and Oncopsis, mostly known from the Northern Hemisphere and including four plant disease vectors, are represented in Australia. At least half of the 45 species (currently in 9 genera) described from Australia are placed in the holdall genus Macropsis Lewis. Assessment of the external and internal (male genitalia) morphological characters resulted in the discovery of at least 50 undescribed species amongst the Australian fauna, twice as many species as currently described. Morphological and molecular characters were further examined and analysed separately. Specimens were evaluated using data captured in a morphological character matrix with over 120 characters, representing 180 taxa, and analysed using Maximum Parsimony methods. Partial COI (549 basepairs) and 28S (663 basepairs) gene sequences were analysed for over 60 specimens, representing 40 taxa from Australia and overseas. DNA sequences for each gene were tested individually and in combination using Neighbour Joining, Maximum Parsimony, and Bayesian Inference methods. Three new undescribed Australian genera were recognised and at least one new generic record for Australia was found. In total, 12 macropsine genera are recognised in Australia in this revision. Phylogenetic trees revealed a distinct clade of Australian-only species and confirmed that 21 of the Australian species currently recognised as “Macropsis” don’t belong to this genus. Only two Australian specimens potentially belong to the genus Macropsis. However, Macropsis was found to be paraphyletic or polyphyletic in some trees and the genus and its subgenera require revision. None of the Australian taxa appear to be closely related to Oncopsis. A combined total evidence (morphological and molecular) analysis, using both Maximum Parsimony and/ or Bayesian Inference methods would likely further elucidate the macropsine relationships.

Submission note: A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy to the Department of Zoology, School of Life Sciences, Faculty of Science, Technology and Engineering, La Trobe University, Bundoora.