Molecular relationships between populations of South African citrus thrips (Scirtothrips aurantii Faure) in South Africa and Queensland, Australia

Abstract   In response to the recent establishment of a population of South African citrus thrips ( Scirtothrips aurantii Faure) in Australia, we used DNA sequence data to examine whether this population is distinct from populations in South Africa. Mitochondrial and internal transcribed spacer (ITS2) DNA from populations from different host plants in Australia and South Africa showed no clear separation between populations that was entirely congruent with host plant or country of origin. Analysis of the ITS2 data was confounded by the presence of multiple different copies of the spacer in some populations. Neither the presence or absence, nor the sequence of these copies was clearly diagnostic for any one population. These preliminary data suggest that the Australian population is not a distinct species or subspecies from the populations of S. aurantii on either citrus or Bryophyllum in South Africa.