Scaptomyza australis Malloch, 1923 is one of Australia’s most often collected drosophilid flies. It is common, especially in Malaise traps, in temperate habitats of southeastern and southwestern Australia. The species has biseriate rows of acrostichal setae, large vibrissal and subvibrissal setae (Figs 3, 13), and the eye, head, and vertex are rounded in lateral view (Fig. 13). Specimens vary in general coloration from meltan (the colour of the Drosophila melanogaster scutum) to blackish-brown (Fig. 6 vs Fig. 9), the tip of the abdomen is invariably dark. The anterior dorsocentral seta is large and well forward (Fig. 6), it is not presutural. Sternite 8 is unusual as noted by Grimaldi (1990:485, J. N. Y. Entomol. 98: 484–488) “in most drosophilines it is divided into two lateral plates and connected anteriorly by a narrow bridge (all of it being the oviscapt)” but in S. australis it has a single, undivided, and setose form (Fig. 5). The species occurs beyond Australia on islands of the South Pacific: on Norfolk, Pitcairn, Vanuatu (Grimaldi, 1990) and the Marquesas Islands (Malloch, 1932, Bernice P. Bishop Mus. Bull. 98: 205–223, and unpubl. obs.).