OBSCUROMYIA, A REMARKABLE NEW GENUS OF THE ENDEMIC AUSTRALIAN TRIBE MYIOTRIXINI (DIPTERA, TACHINIDAE, TACHININAE)

The endemic Australian tribe Myiotrixini is reviewed and a new genus a nd species described. The monotypic genus Myiotrixa Brauen & Bergensta mm, 1893, is known from all States except the Northern Territory, but has been most frequently collected from south-eastern Australia, the s ingle species, M. Prosopina, is a purasite of the native Australian co ckroach Platyzosteria castanea Brunnen. Obscuromyia, a new monotypic g enus of Myiotrixini from northern Western Australia, is described and the relationship between it and Myiotrixa discussed Striking synapomor phies of the male and female terminalia corroborate the sister-group r elationship between Obscuromyia and Myiotrixa. These synapomorphies ar the medially fused pregonites which encircle the base of the aedeagal apodeme in the male, and in the female the lack of sclerotised sterni tes in most of the abdomen and ovipositor, and the non-extensible and non-piercing ovipositon in which segment 8 forms a sclerotised cylinde r incised dorsally and ventually. A revised diagnosis of the Myiotrixi ni is provided along with a diagnostic key to the two genera.