Revision of the Australian bee fly genus Eusurbus Roberts, 1929 (Bombyliidae, Bombyliinae), and description of Zentamyia gen. Nov.

We review the endemic Australian bee fly genus Eusurbus Roberts (Bombyliidae, Bombyliinae) and recognize two described species and three new species. The monotypic genus Bromoglycis Hull is identified as a new junior synonym of Eusurbus. Another species, E. nigracinctus Roberts, is designated as the type species of a new genus Zentamyia gen. nov. This new genus is similar to Eusurbus based on several combined external characters including two-segmented palp, one-segmented flagellomere, open anal cell and cell r₅, and the cell br much longer than cell bm. However, Zentamyia gen. nov. has a more flattened scutum, and the apex of the flagellum is tapered. Moreover, the male genitalia are very different from Eusurbus, the male epandrium is narrow and long, and its posterolateral margin has a cluster of dense hairs; the female lacks a sand chamber, and the sperm pump is long and strong. A morphological phylogeny to Eusurbus species is provided.