Scaeva affinis, commonly known as the white-bowed smoothwing, is a species of hoverfly found in western North America.

[1] The larval form feeds voraciously on aphids.

[2] Scaeva affinis is the only Scaeva likely to be encountered in the Nearctic realm, where it is common in the west and rare in the east.

[4] In 1823, Thomas Say originally described it as "tergum black with three yellow lunules on each side...inhabits Arkansa.

"[5] S. affinis was later combined with (and then determined to be a distinct species and was split back off from) Scaeva pyrastri.