Eristalis stipator, the yellow-shouldered drone fly, is a species of hoverfly native to North America.[1][2][3][4] It is abundant in western North America, with a few scattered records in the east.[4] It flies from mid-May (or as early as February in the south of its range) to early November, and is known to hilltop.[4]
^ abcSkevington, Jeffrey H.; Locke, Michelle M.; Young, Andrew D.; Moran, Kevin; Crins, William J.; Marshall, Stephen A. (2019). Field Guide to the Flower Flies of Northeastern North America. Princeton, New Jersey: Princeton University Press. ISBN9780691189406.
Further reading
Telford, H. S. (1970). "Eristalis (Diptera: Syrphidae) from America North of Mexico". Annals of the Entomological Society of America. 63 (5): 1201–1210. doi:10.1093/aesa/63.5.1201.