Two new species of Homotrixa Villeneuve (Diptera: Tachinidae: Ormiini) from southwestern Australia, with data on biology and ecology

A synopsis of Old World ormiine systematics and biology is given. <i>Homotrixa</i> Villeneuve is differentiated from all four other Old World genera of Ormiini. The generic identity of <i>Homotrixa</i> is discussed. Both sexes of two new species of <i>Homotrixa</i> from southwestern Australia are described, keyed and figured, namely <i>Homotrixa alleni Barraclough</i> sp.n. and <i>H. hirsuta</i> Barraclough sp.n. The puparium of <i>H. alleni</i> is also described. These are the first species of <i>Homotrixa</i> to be described from Australasia; the genus is otherwise known only from the type locality of the type species in Taiwan. Further species of <i>Homotrixa</i> from northern Western Australia, the Northern Territory, Queensland, New South Wales and the Australian Capital Territory remain undescribed. The genus appears not to occur south of 36 °s in Australia. Recorded hosts of <i>H. alleni</i> include three species of Tettigoniidae: <i>Sciarasaga quadrata</i> Rentz, <em>Mygalopsis pauperculus</em> (Walker) and <i>Pachysaga croceopteryx</i> Rentz.