Sphaerophoria asymmetrica explained

Sphaerophoria asymmetrica (Knutson, 1972),^[1] the asymmetric globetail , is a common species of syrphid fly observed across northern North America. Hoverflies can remain nearly motionless in flight. The adults are also known as flower flies for they are commonly found on flowers from which they get both energy-giving nectar and protein rich pollen.^[2] The larvae feed on aphids.^[3]

Notes and References

1. Knutson. Lloyd V.. Taxonomic revision of aphid-killing flies on the genus Sphaerophoria in the Western Hemisphere (Syrphidae). Miscellaneous Publications of the Entomological Society of America. 1972. 9. 1–50.
2. Book: Vockeroth . J.R. . 1992 . The Flower Flies of the Subfamily Syrphinae of Canada, Alaska, and Greenland (Diptera: Syrphidae). Part 18. The Insects and Arachnids of Canada . 1–456 . Canadian Government Pub Centre. Ottawa, Ontario . 0-660-13830-1.
3. Book: Skevington, Jeffrey H . 2019 . Field Guide to the Flower Flies of Northeastern North America. . 9780691189406 .