Tachynomyia have males with the head posteriorly strongly concave and the margins there adorned with long setae. This feature is also shared with Tachyphron and Tachynoides (both genera not found in Tasmania) but can be distinguished by the presence of a digitate process of the cheek (gena) situated low to the base of each mandible. The concavity of the head and the setae fringe serve to hold regurgitate that females will feed from while being carried. Composed of more than 25 Australian species. Tachynomyia abdominalis is the only species known for Tasmania.