Sidarena aurantia, Irwin, Michael E. & Winterton, Shaun L., 2016

Irwin, Michael E. & Winterton, Shaun L., 2016, New genera of Australian stiletto flies (Diptera, Therevidae), ZooKeys 618, pp. 97-128 : 99-103

Taxon classification Animalia Diptera Therevidae

Sidarena aurantia sp. n. Figs 5, 6

Type material.

Holotype male, AUSTRALIA: Western Australia: 158 km S Newman, 9 km N Kumarina Roadhouse, Malaise in wide sandy wash, 21/23.V.2003, M.E. Irwin F.D. Parker, 638 m 24°37.8'S, 117°36.8'E (GPS) (ANIC).

Paratypes. AUSTRALIA: Western Australia: 13 males, same data as holotype (ANIC, CSCA); male, same data as holotype, 18/21.V.2003 (CSCA); male, 74 km S Newman on Great Northern Highway, Malaise in wash with drying pools, 6/18.V.2003, M.E. Irwin F.D. Parker, 631 m 23°56.0'S, 119°46.0'E (GPS) (ANIC).

Diagnosis.

Medium-sized fly with distinct yellow-orange colouration on body; pleuron base colour yellow-orange dorsally, blackish suffusion ventrally and on coxae; abdomen yellow-orange, sternites 1-3 with black suffusion laterally; postocular macrosetae relatively short; femora orange with black suffusion (variable); wing uniformly dark infuscate.

Description.

Body length. 8.0 mm (male). Head. (Fig. 5) Yellowish-grey pubescent; frons flat, brownish-orange pubescent, admixed with scattered black setae dorsolaterally and immediately above antennal socket, narrow dark pubescence present along eye margin; occiput convex with two rows of dark postocular setae, dark setae extending ventrally onto gena and admixed with finer white setae; antennal scape length less than pedicel and flagellum combined, orange-yellow pubescent with numerous robust black setae laterally; pedicel brownish-orange pubescent with numerous black setae; flagellum with extensive brown pubescence; mouthparts yellowish with dark pile. Thorax. Base colour dark yellow-orange on scutum and dorsally on pleuron; scutum overlain with pubescence as broad brown lateral stripes and broad metallic-grey stripe medially (some individuals with brownish suffusion anteromedially); very fine, sparse setal pile on scutum; postpronotal lobe orange pubescent; pleuron dark-yellow orange dorsally, darker suffusion ventrally and anteriorly; pleuron with fine white pile on anepisternum and katatergite; chaetotaxy: notopleural setae (np), 4; supra alar setae (sa), 2; postalar setae (pa), 1; dorsocentral setae (dc), 3; scutellar setae (sc), 1; wings dark infuscate, most cells slightly paler centrally; venation dark; coxae black; femora dark yellow- orange with variable extent of black suffusion, more pronounced on hind femur; tibiae and tarsi dark yellow-orange, distal tarsomeres blackish. Abdomen. Mostly dark yellow-orange, dark suffusion laterally on anterior sternites; silver velutum on tergites 1-5; sparse setal pile on all segments, short and dark dorsally, elongate and white laterally on anterior segments, setal pile denser and more robust posteriorly. Male Terminalia. (Fig. 6) Dark yellow-orange; epandrium numerous dark robust setal laterally, setal pile shorter medially; tergite 8 quadrangular with dark setae laterally; gonocoxite rounded with outer process well developed and rounded, extensive robust setal pile present; hypandrium triangular and fused with gonocoxites laterally; velutum pile very sparse ventrally on gonocoxites (barely evident in some cases); ventral lobe triangular; gonocoxite halves approximating medially, lacking medial atrium; inner gonocoxal process articulating dorsally on gonocoxite, curved medially and with few setae apically; gonostylus narrow and slightly curved medially, numerous setae midway along medial surface; aedeagus with dorsal apodeme of parameral sheath ‘T’ -shaped, subequal in length to ventral apodeme; distiphallus broad distally with small spines apically.

Comments.

Sidarena aurantia sp. n. is known only from a series of males collected in Malaise traps in northern Western Australia. The yellow-orange abdomen is highly distinctive for this species, and it is very similar to Sidarena macfarlandi sp. n. There are subtle differences between the two species, which at this stage, based on the material examined, we recognise as separate species. The abdomen of Sidarena aurantia sp. n. is more uniformly orange (darker on anterior tergites in Sidarena macfarlandi sp. n.), while the lower half of the pleuron, coxae and hind femora are darker in Sidarena aurantia sp. n. The female is unknown for this species.

Etymology.

The specific epithet is a Latin adjective in the nominative feminine singular, meaning orange-coloured, referring to the body colouration.