Larrpana dimidiatipennis (Bowden)
Medium-sized dark flies (wing length 14-18 mm) with dimidiate wings. Male E red, short apical flange, 6-8 thick black flattened spines strongly grouped anterolaterally; very broad upcurved basal flange longer than base. Collar yellow medially, black ventrally on PN. Wing pattern basally black, dimidiate; with distinct line from apex of R1, deeply through base of dc, basal 1/3 of cua. Abdominal tergites black except T2-4 with dark red areas laterally; with dense shiny black scales, T3 with very broad, dense, white scale band, T6-7 with sparse white scales, no cream scales on T2. Sternites with black scales and dense long setae. Female SR round with broad blunt, apical extension.
Male.
Head. Face and frons yellowish-red with transparent yellow scales, black setae longest below shallow frontal depression. Antennal scape 3 x length of pedicel, yellow; pedicel yellow. Narrow line of yellow scales filling indentation at posterior margin of eye.
Thorax. Collar yellow medially, black ventrally on PN. Laterothoracic stripe of long reddish-yellow scales. Scutum black with transparent yellowish-red scales; long reddish-yellow setae anteriorly. Antepronotum and AN with black Ma; long, slightly iridescent, dark-reddish-brown scales at base of wing. Pleural hairs black, scales dark reddish-brown. Scales on APA reddish-brown. LT with black Ma, reddish-yellow medially, cream dorsally. Scutellum dark reddish-brown, black basally; with transparent red scales, black setae. Tympanal ridge and PL with long, fine, white, flattened scales. Legs red, with dark reddish-brown scales. Pulvilli chisel-like wedges, more than 1/3 length of mid-tarsal claws. Halter knob red. Wing. m-cu almost 2 x m-m. Patagium and widened base of C with dark reddish-brown scales. Wing pattern basally black, dimidiate; infuscation in distinct line from apex of R1, proximal to i-r1 by length of r-m, deeply through base of dc to M2; infuscated basal 1/3 of cua, 3/4 of cup, 2/3 of anal. Squama edged with long dense black scales.
Abdomen. Tergites black, except T2-4 with dark red areas laterally, rounded medially, < 1/3 width of abdomen; dense shiny black scales, T3 with dense white scales except posteromedially, T6-7 with sparse white scales. T1 with Ma white dorsally, reddish-yellow medially, black ventrally. Sternites red, black scales and dense long setae. Genitalia. Epandrium red with short apical flange; black setae, 6-8 thick flattened spines strongly grouped anterolaterally; very broad, upcurved, basal flange longer than base of E; SES linear, broader basally. Gonocoxae red, strongly narrowed apically; LAEA deeply convex, extending past G margins; GS cupped within G margins, large subquadrate base projecting slightly apically; very large recurved rami extending past G margins; setae black, short apically, long dense thick tufts medially, directed basally, continuing laterally around apex of H; distinct ventral ridge; G medial line of fusion above H; H large triangular, not projecting, laterally delimited by swollen and expanded G. Epiphallus long, not expanded apically; with lateral margins inturned forming blunt lateral lobes, short medial projection.
Female.
Same as male except: Laterothoracic stripe of long dark reddish-brown scales, TR and PL with long, fine, black, flattened scales. Genitalia. Dorsal T8 A as long as wide, medially divided; T10 with 4 pairs of short, thick AC spines; apical and basal endplates with long processes, pump with numerous unsclerotised papillae; clear, thick-walled ring at junction of rounded BB and SR; SR round with distinctive broad blunt, apical extension.
Comments. The specimen from Cooper Creek has the head detached and carded beneath. This head, with the only complete antennae, is clothed in dense long cream scales, unlike the holotype or the other specimen, and is probably not the head of the specimen concerned. The female holotype has only one, apically broken PP.
Only three specimens of Lar. dimidiatipennis have been collected, all from coastal Northern Territory.