MengualXimoBlack-tie dress code: two new species of the genus Toxomerus (Diptera, Syrphidae) Zookeys26102011201114012610.3897/zookeys.140.1930 Toxomerus nitidus http://species-id.net/wiki/Toxomerus_nitidus (Schiner)Figure 24Mesogramma nitidaSchiner 1868: 349. Type locality: South America [Venezuela] [ST ♂, NMW].Mesogramma ovataHull 1942b: 19. Type locality: Panama, Yape, Tuirar [HT ♀, MCZ] syn. n.Differential diagnosis.

Species with yellow face and a medial black facial vitta in both sexes, geba black. Scutum black, green-bronze pollinose with a medial bluish-white pollinose vitta, sometimes with two submedial whitish vittae. Postpronotum yellow and notopleuron partly yellow, usually with triangular yellow macula anteriorly narrowing towards transverse suture. Wing partly bare basally, with costal cell entirely microtrichose and brown, darker than the rest of the wing except stigma. Male abdomen usually bicolor, with terga 1 and 2 black (tergum 1 with yellow anterior corners) and terga 3 to 5 reddish-orange; postanal process of the male gentialia long. Female abdomen usually shiny black with black lateral margins; tergum 2 with submedial black pollinose fascia and terga 3 and 4 with four black pollinose vittate maculae (Fig. 9).

Species close to Toxomerus dispar and Toxomerus sp. 3 but males of nitidus have black facial vitta and notopleuron partly yellow.

Length

(5): body, 6.1–7.4 (6.9) mm; wing, 5.5–6.9 (6.1) mm.

Distribution.

Guatemala, Costa Rica, Panama, Colombia.

Material examined.

2♂ syntypes, ♀ holotype of ovatus, Non-type material: 7♂ 10♀.

Remarks.

Males of Toxomerus nitidus always have a bicolored abdomen and females may have yellowish markings as noted by Hull (1943) (see Fig. 9), although most of the studied specimens had shiny black abdomens with a black pollinose pattern.

Toxomerus nitidus has been cited few times after its original description but only in catalogues (see Appendix I). I had the possibility to study two syntypes of Toxomerus nitidus and compared them with males of Toxomerus ovatus at USNM. Male genitalia were identical and females of ovatus did key out as nitidus. Thus, I realized that Toxomerus nitidus was only known from male specimens. Therefore, Toxomerus ovatus is here considered to be a junior synonym of Toxomerus nitidus.

16 Toxomerus picudus, lateral 17 Toxomerus picudus, dorsal 18 Toxomerus hauseri, lateral 19 Toxomerus hauseri, dorsal 20 Toxomerus hauseri, head, frontal 21 Toxomerus picudus, head, frontal 22 Toxomerus hieroglyphicus, head, lateral 23 Toxomerus picudus, head, lateral 24 Toxomerus nitidus, thorax, lateral 25 Toxomerus laenas, thorax, lateral 26 Toxomerus paragrammus, abdomen, dorsal 27 Toxomerus incaicus, abdomen, dorsal 28 Toxomerus circumcinctus, male genitalia, 9th tergum and associated structures: a dorsal b lateral 29 Toxomerus anthrax, male genitalia, 9th tergum and associated structures: a dorsal b lateral.

18 Toxomerus dispar: 1 Abdomen of pale male, dorsal 2 Abdomen of dark male, dorsal 3 Abdomen of very dark male, dorsal 4 Abdomen of dark female, dorsal 5 Abdomen of very dark male, dorsal 6 wing 7 Female genitalia: a dorsal, b ventral 8 Male genitalia, 9th tergum and associated structures: a dorsal b lateral 9 Toxomerus nitidus, abdomen of female, dorsal 10 Toxomerus flaviplurus, abdomen of female, dorsal 11 Toxomerus hieroglyphicus, abdomen of male, dorsal 12 Toxomerus laenas, abdomen of male, dorsal 13 Toxomerus sp. 1, thorax, lateral 14 Toxomerus flaviplurus, thorax, lateral 15 Toxomerus anthrax, thorax, lateral (Figs 1, 2, 4, 6, 7 and 8 from Thompson 1981; Figs 915 from Hull 1943).

SchinerIR (1868) Diptera. In: von Wullerstorf-Urbair B (Eds) Reise der österreichischen Fregatte Novara um die Erde in den Jahren 1857, 1858, 1859 unter den Befehlen des Commodore B. von Wüllerstorf-Urbair. Zoologischer Theil, 2 Band. Carl Gerold’s Sohn, Wien, vi + 388 pp, 4 pls.HullFM (1942b) Some flies of the genus Mesogramma.Proceedings of the New England Zoölogical Club 30: 17-24.ThompsonFC (1981) The flower flies of the West Indies (Diptera: Syrphidae).Memoirs of the Entomological Society of Washington 9: 1-200.HullFM (1943) The genus Mesogramma. Entomologica Americana 23: 1–41, 7 pls.