R. C.  Shannon, ?Review of the American xylotine syrphid-flies?, Proceedings of the United States National Museum, vol. 69, pp. 1-52, 1926.

H.  Hippa, ?Classification of Xylotini (Diptera, Syrphidae)?, Acta Zoologica Fennica, vol. 156, pp. 1-153, 1978.