F.  Walker, List of the specimens of dipterous insects in the collection of the British Museum. London: British Museum (Natural History), 1849, pp. Part II, [iii]+231-484. [1849.04.21]; Part III: [iii]+485-687. [1849.06.30]; Part IV. Pp. [3] + 689-1172 + [2] [1849.12.08].

H.  Loew, ?Diptera Americae septentrionalis indigena. Description H. Loew.?, in Diptera Americae septentrionalis indigena, vol. Centuria quinta, Berolini, typis A.W. Schadii: Berliner entomologische Zeitschrift, 1864, pp. 49-104.

H.  Loew, ?Diptera Americae septentrionalis indigena. Description H. Loew.?, in Diptera Americae septentrionalis indigena, vol. Centuria quarta, Berolini, typis A.W. Schadii: Berliner Entomologische Zeitschrift, 1863, pp. 275-326.

F. C.  Thompson, ?Keys to Nearctic Syrphidae (Diptera)?, p. 88, 1991.