Toxomerus jussiaeae Vigé, 1939:66

Toxomerus jussiaeae is a small species (less than 9 mm in lenght), scutum with lateral yellow vitta continuos from postpronotum to scutellum; thorax with yellow macula above procoxa (on proepimeron); scutellum yellow, yellow pilose; male metatibia with basal calcar (=spur); anepimeron partially yellow; and abdomen with pale medial areas with submedial black vittate maculae.

New description:

MALE.

Head: Face produced forward ventrally, with facial tubercle, yellow, yellow pilose; gena black, yellow pilose; frontal triangle yellow, yellow pilose; vertical triangle black, black pilose; antenna yellow, basoflagellomere brown dorsally, arista brown; eye bare, dichoptic, eyes separated by ocellus’ width; occiput black, silvery-golden pollinose, withish-yellow pilose.

Thorax: Scutum black with yellow vita on lateral margin from postpronotum to scutellum, bluish-white pollinose with 2 submedial broad bronze pollinose vittae, yellow pilose; postpronotum yellow, bare; scutellum yellow, yellow pilose, subscutellar fringe sparse with yellow pile. Pleuron mostly black, except proepimeron with yellow macula, posterior anepisternum yellow on posterior half, metaepisternum yellow, and katepisternum black with dorsal yellow macula; metasternum bare; calypter yellow; plumula yellow; halter yellow; spiracular fringes yellow. Wing: Wing membrane hyaline, stigma yellow; microtrichose. Alula broad, microtrichose. Legs: Entirely yellow except pro- and mesocoxae black, femora black subbasally (yellow very basally) forming a broad black ring, metatibia and metatarsus brown, black and yellow pilose. Metafemur arcuate with subbasal large spina (=spur).

Abdomen: Very variable, parallel-sided. 1st tergum black, yellow on lateral and anterior margins; 2nd tergum black with 2 lateral broad yellow maculae; 3rd and 4th terga yellow with posterolateral corners black; 5th tergum yellow with medial black macula; or abdominal pattern very similar to Toxomerus geminatus. Sterna yellow, yellow pilose; genitalia enlarged.

FEMALE.

Differs from the male as follows: frons yellow with medial broad balck vita extending below antennal base not reaching mouth apex and divided in two ventrad to antennae, facial tubercle yellow; legs yellow, metatibia and metafemur brownish; metafemur simple, not arcuate and without calcar. Abdomen more yellow: 2nd, 3rd and 4th and 5th terga yellow with black fascia on posterior margin and 2 submedial vittate maculae, joined in a medial black vitta on 5th tergum.

Toxomerus jussiaeae Vige, 1939.

Vige, L. (1939) A new syrphid fly from Louisiana (Diptera). Entomological News 50, 66-68.

Toxomerus is the single genus of the tribe Toxomerini. Recently, Mengual et al. (2008) included several species of Toxomerus in their phylogenetic analysis and Toxomerini was resolved as a monophyletic group within the clade of the genus Ocyptamus.

Nearctic species known from Illinois, Tennessee, Misouri, Mississippi, Louisana and North Carolina.