Toxomerus circumcinctus (Enderlein) Mengual, Ximo, 2011

Mengual, Ximo, 2011, Black-tie dress code: two new species of the genus Toxomerus (Diptera, Syrphidae), ZooKeys 140, pp. 1-26 : 8

Toxomerus circumcinctus (Enderlein) stat. n. Figure 28

Mesogramma circumcincta Enderlein 1938: 232. Type Locality: Peru, Lima [HT ♂, ZMHB].

Toxomerus circumcinctus as synonym of Toxomerus marginatus : Thompson et al. 1976: 52 (cat.).

Differential diagnosis.

Species with yellow face and a medial broad black vitta, which ends ventrad to antennal bases. Scutum black, yellow pilose, with postpronotum and notopleuron entirely yellow; supra-alar area looks black, although it might have a thin yellow vitta connecting to the yellow postalar callus. Scutellum black with lateral and apical margins yellow. Pleuron black except katepisternum with a dorsal broad yellow macula and posterior anepisternum yellow on posterior third. Halter and calypter yellow. Femora dark brown with yellow apical tips, pro- and mesotibia yellow, metatibia brown with basal and apical extremes yellow, and tarsi brown. Abdomen dark brown, becoming yellowish brown on terga 4 and 5, with continuous yellow lateral margins from tergum 1 to tergum 5.

Toxomerus circumcinctus is similar to Toxomerus anthrax but the last has the notopleuron black and postalar callus dark brown, and the scutellum black with apical margin yellow (Fig. 15). Male genitalia are different (see Figs 28, 29).

Length.

body, 6.0 mm; wing, 5.1 mm.

Distribution.

Species only known from the holotype, collected in Peru.

Material examined.

♂ holotype.

Remarks.

After the original publication ( Enderlein 1938), this species has been only cited in two works. Fluke (1956) listed Toxomerus circumcinctus in his Neotropical catalogue as Mesograpta circumcinctum , and Thompson et al. (1976) synonymized it with Toxomerus marginatus (Say, 1823). Toxomerus marginatus occurs from Canada south to Central America and it was introduced in Hawaii ( Thompson 2010) and it has a typical yellow/black abdominal pattern (http://eol.org/pages/750927/overview). After my study of the circumcinctus type, I consider them two different valid species based on morphological characters and male genitalia.