Aristosyrphus (Aristosyrphus) primus Curran  

From original description (Curran 1941).

MALE.

Head: black, black pilose, the cheeks and sides of the face with brassy-yellow pile; sides of face broadly yellow. Antennae black, the first segment shining, the third brownish gray pollinose; arista brown.

Thorax: black; the humeri, posterior calli and irregular areas on the pleura brownish yellow to brownish red. Legs: black, black pilose, the tibiae and tarsi in large part brown pilose. Wings: orange, yellow in front and basally, yellowish brown posteriorly, the apical fourth brown. Squamae and halteres reddish yellow.

Abdomen: First and second abdominal segments yellow, the second with a broad median brown vitta and the sides brown except on the broad base and apex; third segment brownish with a broad, medianly interrupted apical band and a blackish median vitta; fourth segment black with the apex narrowly reddish, the genitalia shining black. Pile yellow on the first two segments and on very large apical triangles on the third segment, tawny on the apex of the fourth segment, otherwise black. Color of the venter following that of the dorsum but there is no median vitta.

New description:

MALE.

Head: Face straight without facial tubercle, black with 2 lateral white pollinose areas broadening ventrally towards mouth margin, black pilose; gena black, black pilose; dichoptic, frons black, black poise; vertical triangle black, black pilose; antenna black, scape and basoflagellomere elongate (more than 4 times as long as broad), arista subbasal, bare; occiput black, black pilose except yellow pilose ventrally.

Thorax: Scutum and scutellum black, black pilose; postpronotum brownish, black pilose. Pleuron black, black pilose on anepisternum, dorsally on katepisternum and dorsomedially on anepimeron; metasternum bare; calypter and halter orange. Wing: entirely microtrichose except narrow area of vein A2; orange basally, darker on apical 1/3; veins sc-r and M2 present. Alula broad, microtrichose. Legs entirely black, black pilose.

Abdomen: Parallel-sided, 2nd tergum strongly margined; 1st tergum brownish yellow, yellow pilose; 2nd tergum yellow except brown lateral margins and brown medial broad vita, yellow pilose except black pilose on brown areas; 3rd tergum dark brown with 2 sublateral yellow maculae on posterior margin, black pilose except yellow pilose on maculae; 4th tergum black, black pilose; genitalia black, black pilose.