Leucopsina Westwood, 1876

Winterton, Shaun L., 2012, Review of Australasian spider flies (Diptera, Acroceridae) with a revision of Panops Lamarck, ZooKeys 172, pp. 7-75 : 11-13

Leucopsina Westwood, 1876 Figs 2B7-11

Leucopsina Westwood, 1876: 510 - Bigot 1890: 314, 315; Hardy 1921: 78; Paramonov 1957: 524; Neboiss 1971: 219; Schlinger and Jefferies 1989: 375. Type species: Leucopsina odyneroides Westwood, 1876 by monotypy.

Diagnosis.

Body length: 9.0 mm [male], 12.0 mm [female]. Colouration black and yellow [wasp mimic]; head slightly smaller than thorax width, shape hemispherical; postocular ridge and occiput rounded; three ocelli, anterior ocellus reduced in size (female) or absent (male); posterior margin of eye emarginate; eye apilose; position of antennae on head adjacent to ocellar tubercle; male frons width above antennal base not contiguous, eyes contiguous below antennal base; palpus present; proboscis greater than head length; flagellum shape elongate, cylindrical; apex lacking terminal setae; scapes separate; subscutellum enlarged; tibial spines present; pulvilli present; wing markings present (infuscate anteriorly); costa circumambient (weaker along anal margin); costal margin straight; humeral crossvein present; radial veins straight; R1 not inflated distally; pterostigma and cell r1 membranous, not ribbed; R2+3 present; R4+5 originating separately from cell r4+5 (or at same point); cell r4+5 bisected by 2r-m, basal cell narrow elongate, closed; 2r-m joining M1 to R5; R4 with spur vein; medial vein compliment: M1, M2 and M3 present (M3 fused with CuA1); discal cell closed completely; medial veins reaching wing margin; cell m3 present; CuA1 joining M3, petiolate to margin; CuA2 fused to A1 before wing margin, petiolate; wing microtrichia absent; anal lobe well-developed; alula weakly developed; abdominal tergites smooth, rounded, tergites raised along posterior margins; abdomen constricted anteriorly.

Included species.

Leucopsina burnsi (Paramonov, 1957); Leucopsina odyneroides Westwood, 1876.

Comments.

Leucopsina is an endemic Australian genus of contrastingly coloured yellow and black flies, with distinct sexual dimorphism between males and females; male having more pronounced constriction of the abdomen anteriorly. The body colouration, darkening of the costal wing margin and abdominal waist allows members of this genus to be convincing wasp mimics ( Neboiss 1971). Leucopsina can be differentiated from all other acrocerid genera by the wasp mimicking habitus, elongate cylindrical flagellum, apilose eyes and elongate mouthparts. Neboiss (1971) provides a key to species of this genus. Leucopsina burnsi was originally described as a variety of Panops flavipes (= Mesophysa flavipes Latreille, 1811) but subsequently transferred to Leucopsina and thoroughly differentiated from Leucopsina odyneroides by Neboiss (1971).