Over much of southern temperate Australia pastures are dominated by imported grasses. In such areas the dominant grass-living Thripidae are species of Aptinothrips, Chirothrips and Limothrips, all introduced from Europe, also more rarely Apterothrips that presumably came from the west coast of North America (Hoddle et al., 2008). In contrast, Australian native Poaceae in southern Australia support one species of Caprithrips, and three species of Odontothripiella, all endemic to Australia. Karphothrips breeds only on the leaves of the native sword-grass Gahnia (Cyperaceae), and Moundothrips lives either on Poaceae or Restionaceae. Physemothrips is found only much further south, on grasses in the Antarctic Islands.
In the warmer parts of Australia, widespread introduced grasses such as Buffel Grass, Cenchrus ciliaris, usually bear New World species of the genera Arorathrips and Plesiothrips. These thrips species now occur throughout the tropics and subtropics, and they are commonly found together with species such as Anaphothrips sudanensis, A. obscurus, and A. swezeyi. The introduced tropical grasses also support species of Caliothrips, Edissa, Phibalothrips and Stenchaetothrips, all of which presumably originated in the Old World tropics. Certainly, there is considerable overlap between the thrips fauna of northern Australia and that of Indonesia and Southeast Asia (Mound & Tree, 2011). But it is on the native grasses of northern Australia that the greatest diversity of endemic grass thrips is found, with species of Aliceathrips, Kranzithrips, Masamithrips, Monothrips, Ozanaphothrips and Striathrips known only from Australia. In contrast, the genera Bolacothrips, Bregmatothrips, Exothrips, Monothrips, Organothrips, Parexothrips, Stenchaetothrips and Takethrips all occur in other tropical countries, despite including some species that are presumed to be endemic to Australia. This thrips fauna of northern Australia is particularly complex, and the patterns of structural variation between populations are not yet fully understood, particularly in Aliceathrips and Masamithrips.