Flies regifted? Did Australia give New Zealand its horse flies (Scaptia Diptera: Tabanidae)

Bryan Lessard *1, David Yeates 2, Stephen Cameron 2, John Trueman 3


1 CSIRO Ecosystem Sciences, Clunies Ross St, Acton, ACT 2601, Australia
2 CSIRO Ecosystem Sciences, GPO Box 1700, Canberra, ACT 2601, Australia
3 Australian National University, Canberra, ACT 200, Australia

Horse flies are notorious for their feeding behaviour and transmission of disease in both humans and livestock, but also have a beneficial and underestimated role in pollination.  The tabanid genus Scaptia has an exclusively austral distribution, occurring in Australasia, New Zealand, and South America. Contemporary molecular techniques are combined with traditional morphological methods to create the first robust phylogenetic hypothesis for Scaptia. We analysed a 5KB concatenated matrix of CAD, PGD, AATS, 28s, COI and COII DNA sequences, and 30 morphological characters.  Results suggest that Scaptia and its five included subgenera are monophyletic, however new subgenera will be required for a small subset of species.  Divergence time estimation using the molecular data calibrated with fossils suggests that the New Zealand Scaptia evolved in situ from a Gondwanan ancestor, rather than being colonized by long distance dispersal after the Oligocence drowning.


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