The first study of genus Phacaspis, external characteristics were considered for classification (Grootaert and Meuffels, 1988). The result showed that stalk hypopygium of Phacaspis was similar to genus Medeterinae but the shape of antennae and the external bristle on the posterior coxae were different. In addition, Phacaspis has characters similar to other genera as well. It was reasonable to infer that the position of genus Phacaspis in family Dolichopodidae was uncertain (incertae sedis).