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

X.  Mengual, Ståhls, G., and Rojo, S., ?First phylogeny of predatory Flower flies (Diptera, Syrphidae, Syrphinae) using mitochondrial COI and nuclear 28S rRNA genes: conflict and congruence with the current tribal classification?, Cladistics, vol. 24, pp. 543-562, 2008.