Sidarena geraldton, 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 : 105-107

Taxon classification Animalia Diptera Therevidae

Sidarena geraldton sp. n. Figs 10, 11

Type material.

Holotype male, AUSTRALIA: Western Australia: Geraldton, 7.vii.1972, N. McFarland (at light) (ANIC) (MEI028795).

Diagnosis.

Relatively small and slender species; scape grey pubescent, relatively narrow; pleuron uniform grey pubescent; abdomen dark brown-black; scutum with broad metallic grey stripe with medial brown suffusion; wing with faint infuscation, darker anteriorly and along veins; legs brown.

Description.

Body length. 5.5 mm (male). Head. Occiput silver-grey pubescent with two rows of elongate postocular setae; frons flat, dark brown pubescent admixed with elongate black setae, especially just above antennal socket; pubescence also as black line along eye margin and silver spot lateral to antennal socket; face silver pubescent; gena silver-white pubescent with fine, white, elongate setae; antenna as long as head length, scape similar width to pedicel and flagellum and as long as both combined, brown with grey pubescence with extensive black setae on outer surface; flagellum brown pubescent, tapered to dark arista; mouthparts dark brown with black setae. Thorax. Dark base colour overlain with extensive grey pubescence; scutum overlain with pubescence as broad brown lateral stripes and broad metallic-grey stripe medially with brown suffusion along axis; scutellum yellowish with grey pubescence; pleuron mostly grey pubescent, lacking setae except anepisternum and katatergite which have scattered short, white setae; coxae dark grey pubescent; legs uniformly brown with black setae; chaetotaxy: np, 4; sa, 1; pa, 1; dc, 3; sc 1; wing uniformly tinted infuscate, venation dark. Abdomen. Dark brown-black with cream-yellow areas laterally and on tergite 1, extensive silver velutum on at least tergites 1-4 in male, velutum not unidirectional, but with triangular pattern depending on angle viewed; thin setae present on all segments, black medially and posteriorly, white laterally and anteriorly. Male terminalia. (Fig. 11) Epandrium longer than wide, setae more robust laterally; cerci distinctly separate, ovoid; tergite 8 quadrangular with short robust setae laterally; gonocoxite wider than long; outer gonocoxal process elongate, pointed; inner gonocoxal process elongate, its apex protruding posteriorly to apex of gonostylus but more thinly sclerotized and slightly spatulate apically; gonostylus slender with scattered black setae anteriorly at about 1/3 distance from base to apex; ventral lobe broad and rounded; hypandrium connected to gonocoxite along anterior edge; aedeagus shape similar to other species in genus.

Comments.

Sidarena geraldton sp. n. is a western species known only from the male holotype collected from Geraldton, Western Australia. This is a relatively diminutive species with dark legs, abdomen and narrow wings.

Etymology.

The specific epithet is the unaltered place name of the type locality for this species; a noun in apposition.