Eristalis dimidiata

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]

Eristalis dimidiata
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Diptera
Family:	Syrphidae
Genus:	Eristalis
Species:	E. dimidiata
Binomial name
Eristalis dimidiata Wiedemann, 1830
Synonyms[1]
Eristalis chalybaeus Macquart, 1842 Eristalis chalybeus Macquart, 1842 Eristalis dimidiatus Wiedemann, 1830 Eristalis haesitans Walker, 1849 Eristalis incisuralis Macquart, 1850 Eristalis inflexus Walker, 1849 Eristalis lherminierii Macquart, 1842 Eristalis niger Macquart, 1834

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]

Description

Black-shouldered drone flies have opaque, infuscated humeral cells (at the base of their wings), with the rest of the wing entirely hyaline (transparent), except for possibly a diffuse medial spot on the wing.^[5][6] Their hind tarsi are entirely black.^[6] Overall, much of the fly is black, though the wings are mostly transparent and the posterior margins of the abdominal segments are white. Their pterostigma are dark brown and distinct.^[4][5] They have one to six short bristles on the dorsus (back) of their arista.^[5]

Female, showing the darkened, opaque, infuscated humeral cells on the leading edges of the wings, close to the base.

Female