''Scaeva affinis'', commonly known as the white-bowed smoothwing, is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

hoverfly Hover flies, also called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while ...

found in western North America. The larval form feeds voraciously on aphids. ''Scaeva affinis'' is the only ''

Scaeva ''Scaeva'' is a genus of hoverflies. The taxonomy of the genus, and the related genera '' Simosyrphus'' and ''Ischiodon'' has been discussed by Láska et al. (2006) Species * ''Scaeva affinis'' (Say, 1823) * ''Scaeva albomaculata'' ( Macquar ...

'' likely to be encountered in the Nearctic realm, where it is common in the west and rare in the east. This species is believed to be migratory.' In 1823,

Thomas Say Thomas Say (June 27, 1787 – October 10, 1834) was an American entomologist, conchologist, and herpetologist. His studies of insects and shells, numerous contributions to scientific journals, and scientific expeditions to Florida, Georgia, the ...

originally described it as "

tergum A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'm ...

black with three yellow lunules on each side...inhabits Arkansa." ''S. affinis'' was later combined with (and then determined to be a distinct species and was split back off from) ''

Scaeva pyrastri ''Scaeva pyrastri'', common name the pied hoverfly, is a species of hoverfly. Distribution These hoverflies are present in most of Europe, the Near East, the East Palearctic realm, the Nearctic realm, North Africa, and the Indomalayan realm. ...

''.

References

Syrphini Insects described in 1823 Taxa named by Thomas Say Hoverflies of North America {{Syrphidae-stub