Orthonevra Macquart, 1829

Miranda, Gil F. G., Soares, Matheus M. M. & Thompson, Christian, 2024, The Neotropical Orthonevra Macquart, 1829 (Diptera: Syrphidae), Zootaxa 5484 (1), pp. 1-78 : 6-7

Genus Orthonevra Macquart, 1829

Orthonevra Macquart 1829: 188 (40). Type-species, Chrysogaster elegans Meigen (monotypy). Refs. Sedman 1964 (revision, keys), 1966a (revision, keys), b (female genitalia).

Thompson 1972: 119–121 (redescription and taxonomic history); Thompson et al. 1976: 90–91 (catalog); Thompson 1981: 141 (taxonomic notes).

Orthoneura authors (misspelling). Thompson et al. 1976 (emendation).

Cryptineura Bigot 1859: 308 . Type-species, C. hieroglyphica Bigot (monotypy) = nitida Wiedemann.

Chrysogaster authors (part).

Differential diagnosis: Face and frontal triangle/frons rugose/regulose, frons with medial longitudinal sulcus; antennae slightly elongate, postpedicel and pedicel elongated [pedicel short in O. chilensis Thompson and O. quadristriata (Shannon & Aubertin) ] and without setae; lunule smooth; eyes often with complex markings; occiput inconspicuous dorsally in lateral view; body with metallic reflections; scutum with matte dark vittae; scutellum without subscutellar fringe, with protuberances (except for O. chilensis ) on most of its surface from where the pile arises; wing often with dark markings; vein M1 forming a right or obtuse angle (i.e. recessive in O. chilensis and O. quadristriata ) with vein R4+5; alula wholly microtrichose; abdomen mostly dark matte medially and metallic shiny laterally. Male genitalia: subepandrial sclerite as two rectangular plates (arms), which might widen or narrow towards apex, and are only narrowly connected at the base (forming a V-shape); postgonites merged into the hypandrium; phallapodeme fused to base of phallic complex, dorsal to the basal tubular process; phallus complex, with a variable apical process (usually hook or beak-like, hypothesized here to anchor inside the genital chamber of the female), pilose at least medio-dorsally, and with a basal tubular process (where the ejaculatory apodeme connects dorsally), originating between the base of the phallus and the fused apex of the phallapodeme, which bears the phallotrema on its apex. Female genitalia: sternum 8 large and wide; sternum 9 usually as a distinct plate.

Comments. The species Orthonevra bellula (Williston) and O. nitida were not confirmed as occurring in the Neotropical region (also see Sedman 1964), but are added to the key in case they occur in the border between the Nearctic and Neotropical areas of Mexico and to highlight the differences between those species and the currently known species with Neotropical distribution. We found Neotropical specimens that agree with O. nitidula (Curran) , a mainly Nearctic species, and hereby extend its records to that region (see species distribution and Fig. 41 ). Thompson (2006) also lists a morphospecies ‘79-3’ from Ecuador which has an immaculate wing according to his key in that work; unfortunately, we couldn’t find any specimens with that description, neither among material under Thompson’s care at the USNM. However, all the other morpho-species previously delimited by Thompson are represented in the current work.

Figures

FIGURE 41. Distribution map for Orthonevra flukei (sedman, 1964), O. gli sp. nov., O. hypnotica sp. nov., O. nitidula (Curran, 1925), and O. sternolobosa sp. nov.