Common in many parts of Maryland, especially in the fall. In Maryland, it flies primarily from April to May and September to early November. The summer gap in observations suggests the possibility that this is at least in part a migratory species in the state. Some nearctic flower flies (family Syrphidae) have been found to be migratory, but flower fly migration in North America has been little studied overall. In the fall it can be found on a variety of flowering plants in meadows and fields near the coast, but it is otherwise associated with forests.
Description
By far the most common large flower fly in Maryland with the general pattern of a wide, dark abdomen punctuated by several thin white transverse lines. The small black triangular area at the base of the wings distinguishes it from all other members of the genus except E. saxorum, which shows a variable amount of metallic blue, visible from certain angles, on the abdomen and/or scutum.
Use of media featured on Maryland Biodiversity Project is only permitted with express permission of the photographer.
A Black-shouldered Drone Fly in Baltimore Co., Maryland (3/23/2019). Determined by Ken Wolgemuth and Bill Dean via BugGuide.
View Record Details
Media by
Emily Stanley.
Black-shouldered Drone Fly in Prince George's Co., Maryland (4/15/2021). (c) Sergei Drovetski, all rights reserved.
View Record Details
Media by
Sergei Drovetski.
A Black-shouldered Drone Fly in Baltimore Co., Maryland (4/8/2017). Determined by Ken Wolgemuth/BugGuide.
View Record Details
Media by
Emily Stanley.
Black-shouldered Drone Fly in Prince George's Co., Maryland (4/15/2021). (c) Sergei Drovetski, all rights reserved.
View Record Details
Media by
Sergei Drovetski.
A Black-shouldered Drone Fly in Talbot Co., Maryland (9/23/2019). Verified by Kelsey J.R.P. Byers/BugGuide.
View Record Details
Media by
Jim Moore.
Black-shouldered Drone Fly in Anne Arundel Co., Maryland (5/7/2016). (c) Timothy Reichard, all rights reserved.
View Record Details
Media by
Timothy Reichard.
A male Black-shouldered Drone Fly in Prince George's Co., Maryland (10/6/2016). Verified by Ken Wolgemuth/BugGuide.
View Record Details
Media by
Barbara Thurlow.
Black-shouldered Drone Fly in Frederick Co., Maryland (4/5/2015). Verified by Kelsey J.R.P. Byers/BugGuide.
View Record Details
Media by
Mark Etheridge.
Black-shouldered Drone Fly in Baltimore City, Maryland (10/14/2013). Verified by Martin Hauser/BugGuide.
View Record Details
Media by
Pauline Horn.
A Black-shouldered Drone Fly in Baltimore City, Maryland (4/23/2009). Determined by Ted Kropiewnicki/BugGuide.
View Record Details
Media by
Thomas Wilson.
A Black-shouldered Drone Fly in Baltimore Co., Maryland (4/27/2014). Determined by Martin Hauser/BugGuide.
View Record Details
Media by
Steve Bennett.
Eristalis dimidiata, the black-shouldered drone fly, is a species of hoverfly native to much of Canada and the eastern and northern United States.[1][2][3][4][5] It flies year-round in southern areas and from late March to mid-November further north.[5] It is one of the earliest hoverflies to fly in the spring, and as such likely overwinters as an adult.[5] It lives primarily in forests.[5]
Hoverflies get their names from the ability to remain nearly motionless while in flight. The adults are also known as flower flies as they are commonly found on and around flowers, from which they get both energy-giving nectar and protein-rich pollen. The larvae are aquatic filter-feeders of the rat-tailed type.[4][6]
^ abcdSkevington, 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.
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.