Macrosiagon vittata (Erichson), M. mutilata (Gerstaecker) and M. gracilis Manfrini de Brewer are assigned to the new provisional species group vittata on the basis of possessing two protibial apical spurs, a transversely flattened vertex not elevated above the dorsal margin of the eyes and thread-like antennal rami in males. A key to these species is presented and each is redescribed. The following nomenclatural changes are made: M. mutilata (Gerstaecker) (= M. quadrimaculata (Gerstaecker), = M. melanoptera (Chevrolat), = M. vitraci (Fleutiaux and Sallé)) new synonymies, and M. vittata (Erichson) (= M. vittata var. biinterrupta Pic, = M. vittata var. bahiensis Pic, = M. vittata var. latelutea Pic, = M. discicollis (Gerstaecker), = M. brasiliensis Pic, = M. pectoralis Pic) new synonymies. Lectotypes and paralectotypes are designated for the following species: M. mutilata, M. quadrimaculata and M. vittata. A brief discussion of Macrosiagon taxonomy and phylogenetic relationships within the Macrosiagonini is also presented.