Palirika decora, Lambkin & Yeates, 2003: 812.

Small black, rounded, dense, adpressed metallic scales dorsally on thorax and abdomen (Fig. 6D); no abdominal white scales, sternal vestiture black, not metallic. Epandrium rounded, strongly curved, red, extended smoothly basolaterally (Fig. 4E, F). Gonocoxae deeply narrowed medially, with thickened setae ventromedially, tuft of 6–8 very long, basally-directed, thick setae medially; H projecting in lateral view; EP without lateral lobes, medial projection laterally; LAEA large, convex, extending to G margin; EJA racquet-shaped, longer than the length of G (Fig. 5). Female T₈ A little more than marginal thickening (Fig. 6F), spermathecal tube more than 8 × length of SP, clear thick-walled ring joining clear thick-walled BB and pigmented subquadrate SR.

Included species: Palirika anaxios Lambkin & Yeates 2003, Palirika basilikos Lambkin & Yeates 2003, Palirika blackdownensis Lambkin & Yeates 2003, Palirika bouchardi, Palirika culgoafloodplainensis sp. n., Palirika cyanea Lambkin & Yeates 2003, Palirika danielsi Lambkin & Yeates 2003, Palirika decora, Palirika mackenziei sp. n., Palirika marginicollis (Gray, 1883), Palirika viridula Lambkin & Yeates 2003, Palirika whyalla Lambkin & Yeates 2003.

Holotype. Queensland: ♂, 28.94°S, 146.918°E, Culgoa Floodplain NP, 7km NNW Toulby Gate, 160m, (CG4AM), Malaise, 20Jan-19Mar2010, C. Kelly, A. Coward, 19273, [dissected], PS1937, A006859, T165704 (QM). Condition: Fair (see remarks below).

Wing length 20.0 mm

Large dark flies with distinct triangular basal infuscation on the wings wings. Face and frons with transparent scales. Occiput with white scales broadly filling indentation. Collar whitish-cream. Broad laterothoracic stripe of dense white flattened scales. Scutum black with lime-green metallic scales except pink metallic scales anterolaterally to PR bristles and posterolaterally anterior to APA. Scutellum with lime-green metallic scales; very long, white, flattened-scale fringe on posterior margin. Widened base of costa with reddish-brown scales, white scales posteriorly. Wing pattern dimidiate (Fig. 4C); with distinct indentation base of first r₂₊₃; extension along R₄₊₅, covering basal 1/3 of first r₂₊₃ and r₅; indistinct mottling base of m₁ along m-m; no infuscated band; anal and posterior cells with apically notched hyaline area, infuscation extending along CuA₂; cup infuscated basal 4/5; anal infuscated basal 2/3. Squama edged with dense white scales admixed with some reddish-brown scales. T₁ with Ma white dorsally, black medially and ventrally, dense very long flattened white scales posterolaterally. Abdominal tergites black with bluish-green scales. Epandrium with long setae grouped loosely apically. Epiphallus with short, medial projection. G with long black setae medially, directed basally, longest on weak ventral ridge; LAEA very large, extending well beyond G margins.

Male. Head (Figs 4A–D). Face red with transparent scales, frons brown with transparent scales; setae black, frontal depression distinct. Antennal scape red, 3 × length of pedicel, with long black setae dense laterally and ventrally; pedicel red; PP black, conical, 3 × length of pedicel, distinct apical joint; BSM rod-like, black, 3 × length of pedicel; ASM black, conical, length at least width of BSM (Fig. 4B). Occiput with white scales broadly filling indentation (Fig. 4A).

Thorax.(Figs 4C–D). Collar whitish-cream. Broad laterothoracic stripe of dense white flattened scales (Fig. 4D). Scutum black with lime-green metallic scales except pink metallic scales anterolaterally to PR bristles and posterolaterally anterior to APA; black setae. Pleural hairs black with reddish-brown iridescence. AN with black Ma; long, lightly iridescent scales at base of wing reddish-brown; long flat broad pale brown scales posteromedially. K with very long fine reddish-brown scales medially. Ma on LT black with reddish-brown iridescence. Tympanal ridge and PL with dense very long fine white flattened scales. Scutellum red, darker basally with lime-green metallic scales; very long, white, flattened-scale fringe on posterior margin. Legs. Legs reddish-brown, darkening apically, with black scales and setae, tarsi dark reddish-brown to black; fore-tarsi with straight microtrichia. Pulvilli sharp, curved, 1/3 length of mid- and hind-tarsal claws. Halter knob reddish-brown with apical margin yellow. Wing (Fig. 4C), cup narrowly open or closed only at wing margin. Patagium distinct with dense white long flat scales. Widened base of costa with reddish-brown scales, white scales posteriorly. Wing pattern dimidiate (Fig. 4C); with distinct indentation base of first r₂₊₃; extension along R₄₊₅, covering basal 1/3 of first r₂₊₃ and r₅; indistinct mottling base of m₁ along m-m; no infuscated band; anal and posterior cells with apically notched hyaline area, infuscation extending along CuA₂; cup infuscated basal 4/5; anal infuscated basal 2/3. Anal basal edge with dense black scales; alula edged with dense reddish-brown scales; squama edged with dense white scales admixed with some reddish-brown scales.

Abdomen.Black, T_1–4 dark reddish-brown posterolaterally; tergites with bluish-green scales; T₁ with Ma white dorsally, black medially and ventrally, dense very long flattened white scales posterolaterally; T_2–7 with tufts of long, black setae laterally and posteriorly. Sternites black with dark reddish-brown scales and hairs. Genitalia (Figs 4E–H, 5A–H). Epandrium strongly convex, red with convex apical margin; tapering basal flange; long, black setae loosely grouped apically; SES large, fused medially (see Fig. 4E). Gonocoxae red, narrowed apically; GA short, triangular; thick tufts of long black setae medially, directed basally, longest on weak ventral ridge (Fig. 5C); EJA very large, extending well beyond gonocoxal margins, racquet-shaped; LAEA very large, extending well beyond G margins, deeply convex (Fig. 5A); AAES strong wedges (Fig. 5E, H); GS (Fig. 5B) cupped within G margins, large subquadrate base projecting apically; EP long, expanded slightly apically, without lateral lobes, short medial projection; medioventral flange above AE present (Fig. 5G); large recurved R (Fig. 5F, H); H triangular, projecting slightly in lateral view (Fig. 5C).

Female. Unknown.

Etymology. This species is named culgoafloodplainensis after the remote Queensland Culgoa Floodplain National Park where the type specimen was collected, and where CLL and Noel Starick received so much hospitality, enthusiasm, and encouragement over the years from all the staff, but especially RIC Andy Coward.

(Fig. 11). This species has only been collected from the type locality in central south-western Queensland.

Due to extended storage in propylene glycol as retrieval of sample was prevented by extensive and prolonged flooding the specimen bears few setae, hairs or scales, therefore colour patterns referred to in the description are based on those remaining, usually at junctions of sclerites.

Holotype. Queensland: ♀, 26°43.7'S, 142°39.1'E, Plevna Downs, Tompilly Hill summit, 13 Dec 2007, C. Lambkin, N. Starick & R. Mackenzie, 15454, sweep net, hilltopping, 220m, [dissected], PS1893, A007533, T152481 (QM). Condition: Good.

Wing length 9.0 mm.

Small dark flies with heavily infuscated wings, hyaline only apically and medial spot. Face orange with shiny reddish-brown scales, frons black with shiny black scales. Collar yellow. Narrow laterothoracic stripe of whitish scales. Scutum black with dull lime-green metallic scales except pinkish metallic scales anterolaterally and posteromedially. Scutellum dark brown, darker basally with royal-blue metallic scales, purple metallic scales laterally and posteriorly. Widened base of costa with shiny reddish-brown scales, no paler scales posteriorly. Wing pattern broadly dimidiate (Fig. 6A); black with hyaline areas, apically and medially. Apical hyaline area covering extreme apex of r₁, apex of first r₂₊₃, apical half of second r₂₊₃, all r₄, and extreme apex r₅. Medial hyaline area covering middle of dc extending from M₁ across m-cu and into m₂. Paler prediscoidal opaque area distinct. Alula and squama edged with long broad grey scales. T₁ with white Ma; long white flattened scales posterolaterally. Tergites black with royal-blue metallic scales that reflect purple (Fig. 6D). Female T₈ A short, plate-like support distinct.

Female. Head.(Figs 6B–E). Face orange with shiny reddish-brown scales, frons black with shiny black scales; setae black, longest below distinct frontal depression. Antennal scape red, 3 × length of pedicel, with long black setae dense laterally and ventrally; pedicel red with black setae shorter and sparser dorsally; PP conical, 5 × length of pedicel, black with silvery pruinescence, distinct apical joint; BSM rod-like, expanded apically, reddish-brown, 2 × length of pedicel; ASM reddish, conical, length less than width of BSM (Fig. 6E). Occiput with shiny black scales broadly filling indentation.

Thorax. (Figs 6B–D). Collar yellow. Narrow laterothoracic stripe of whitish scales. Long white flattened scales posteromedially. Scutum black with dull lime-green metallic scales except pinkish metallic scales anterolaterally and posteromedially; black setae. AN with black Ma, long yellow setae anteriorly; long, lightly iridescent scales at base of wing black. Prealar bristles strong, black and long. Postalar bristles strong, black and reaching almost apex of scutellum. Pleural hairs black with reddish iridescence. Ma of LT black, reddish-brown dorsally. Tympanal ridge and PL with yellowish flattened scales. Scutellum dark brown, darker basally with royal-blue metallic scales, purple metallic scales laterally and posteriorly; strong, black apical bristles. Legs. Reddish-brown, tarsi darker; scales and setae black. Pulvilli sharp, curved, half length of mid- and hind-tarsal claws. Halter knob dark reddish-brown, posteromedial edge broadly yellow. Wing (Fig. 6A), cup open. Widened base of costa with shiny reddish-brown scales, no paler scales posteriorly. Wing pattern broadly dimidiate; black with hyaline areas, apically and medially. Apical hyaline area covering extreme apex of r₁, apex of first r₂₊₃, apical half of second r₂₊₃, all r₄, and extreme apex r₅. Medial hyaline area covering middle of dc extending from M₁ across m-cu and into m₂. Paler prediscoidal opaque area distinct. Anal edged with long black scales basally. Alula edged with long broad grey scales. Squama edged with dense overlapping long grey scales.

Abdomen. (Figs 6C–D). T₁ with white Ma; long white flattened scales posterolaterally. Tergites black with royal-blue metallic scales that reflect purple when not viewed dorsally, pleura with lateral tufts of long black setae on T_2–7. Sternites black, with black scales and setae. Genitalia (Fig. 6F–H). Dorsal T₈ A short, plate-like support distinct; T₁₀ with 4 pairs of stout AC spines. Furca with 2 long broad posteriorly directed arms with small recurved hook-like dorsal extensions apically.

Male. Unknown.

This species is named mackenziei to acknowledge the enthusiasm and interest in all kinds of natural history by the Mackenzie family of Plevna Downs Station where the type, and only, specimen was collected. Since 2007, following the discovery of dinosaurs on their property, together with a large undescribed spider, CLL and Noel Starick have been welcomed by the Mackenzie family. Robyn Mackenzie was thrilled to be helping catch hill-topping beeflies on the summit of Tompilly Hill when the only female specimen of this unusual Palirika was captured (Fig. 1A). We have happily instructed the family, the local Natural History Society, students, teachers, regional property owners and community members on the ins and outs of biodiversity of arid areas, especially the insects.

(Fig. 11). This species has only been collected from the type locality in remote far south-western Queensland.

Dimidiate wing pattern as in Figure 7A–B, dark basally, hyaline apically; infuscation forming a distinctly separated, basal triangle leaving the apex of the posterior cubital and anal cells broadly hyaline. Cream laterothoracic stripes, white scale bands on T₃, sparse white scales on T_6–7. Epandrial basolateral flange longer and broader than the length of the epandrial base. Gonocoxae deeply narrowed medially, tufts of thickened setae on distinct ventral flange that projects basally; EP with rounded, projecting, lateral lobes; short, wedge-shaped AAES; EJA long. Sperm pump long with unpigmented papillae, collar or clear ring surrounding join between BB and thick-walled round SR.

Included species: Larrpana bushblitz sp. n., Larrpana dimidiatipennis, Larrpana collessi Lambkin & Yeates 2003, Larrpana zwicki.

Holotype. Western Australia: ♂, 29.302°S, 116.725°E, Karara, 23.5km ESE Boiada Camp, 356m, 17 Sep 2009, Lambkin, sweeping, 18402, rocky hilltop, hilltopping, PS1714, WAM 82396 (WAM). Condition: Good.

Paratypes. Western Australia: 1♂, same data as holotype, T152479 (QM); 1♂, 29.309°S, 116.731°E, Karara, Forest lookout, 24.4km SE Boiada Camp, 17 Sep 2009, 18405, Lambkin, sweeping, 410m, rocky hilltop, hilltopping, [dissected], PS1894, WAM 82397 (WAM); 1♂, same data Forest lookout, A007534, T152480 (QM).

Wing length 14 mm

Medium, dark, densely setose, flies with black, dimidiate wings with five indistinct yellowish spots (Fig. 7A, B); infuscation indented in 1st r₂₊₃; no lobe or medial band; dc infuscated except for rectangular hyaline area at junction of m-cu and m-m. Thoracic collar yellow. Dorsal surface of thorax, scutellum and abdomen covered with long upstanding setae, producing distinct fluffy appearance. T₃ with uninterrupted white band of upstanding scales narrowing medially, laterally spanning entire tergite. Alula and squama edged with dense long cream scales; proximal 1/3 of anal cell edged with black scales, longest basally. Male (Fig. 8) E with basal flange very long, broad, extending basally, apically recurved. H large, subquadrate in lateral view, distinctly projecting.

Male. Head(Fig. 7A–D). Frons reddish-brown, face red, face and frons with transparent scales, black setae longest below shallow frontal depression. Antenna (Fig. 7C). Scape 2.5 × length of pedicel, red; pedicel red; PP long, 3–4 × length of pedicel, as long as scape and pedicel combined, dark reddish-brown, with reddish pruinescence; BSM dark reddish-brown, 2 × length of pedicel, not expanded apically; ASM minute blunt cone, length less than width of BSM. Narrow band of cream scales at posterior margin of eye medially.

Thorax (Fig. 7A, B). Collar yellow. Very broad distinct laterothoracic stripe of dense long white scales. Scutum black; scales long, reddish-brown, white posteriorly; long dense black setae, longest anteriorly and posteriorly. AN and PN with Ma admixed black and reddish-brown; long, slightly iridescent, reddish-brown scales at base of wing. Pleural hairs black, with reddish-brown iridescence. Scales on APA white. Laterotergite with dark reddish-brown Ma ventrally, white dorsally and red medially. Plumula with dense long white scales and TR with dense long yellow scales. Scutellum dark reddish-brown, black basally; scales black basally, transparent pale-brown medially and posteriorly, posterior scales longest; long dense, black setae. Legs reddish-yellow with black scales. Microchaetae on fore-tarsi curved apically. Pulvilli straight sharp cones, more than 1/3 length of mid- and hind-tarsal claws. Halter knob red with pale whitish apical edge. Wing (Fig. 7A, B). Widened base of C with black scales with pale band posteriorly. Spur-veins present on base of R₄ extending into r₄ and on apex of m-cu extending into m₂ in some specimens; bump at basal bend of m-cu. Wing pattern (Fig. 7A, B) black, dimidiate, broad basal infuscation following R proximal to i-r₁ to wing margin in apical 4/5 anal cell; indented in 1st r₂₊₃; no lobe or medial band; dc infuscated except for rectangular hyaline area at junction of m-cu and m-m; apex hyaline. Dark yellowish-brown areas bordering base of CuA₁, join of R₁ and R_s, r-m continuing onto base of R₂₊₃, and base m-cu; together with prediscoidal opaque area forming indistinct pentagonal pattern of spots within infuscation. Anal and cup infuscated for basal 4/5. Alula and squama edged with dense long cream scales; proximal 1/3 of anal cell edged with black scales, longest basally.

Abdomen.

(Fig. 7A, B). Tergites black with red anterolateral areas medially rounded on T_2–3 < 1/4 width of tergite. Scales dense, black except: T₃ with uninterrupted white band of upstanding scales narrowing medially, laterally spanning entire tergite; T_1–3 with dense long white upstanding lateral scales; T_6–7 with white scales. T₁ with Ma white dorsally and laterally, yellow ventrally. T_1–3 with long dense white setae laterally, pale brown anteriorly, and black posteromedially; T_4–7 with long dense thick black setae. Sternites red with sparse long pale reddish scales, dense long black setae. Genitalia (Fig. 8). Epandrium red with distinct anterolateral flange bearing cluster of long black setae; basal flange very large, long, broad, extending basally and apically upcurved; setae black, loosely grouped anterolaterally; SES very long, linear, broadened basally. Gonocoxae red, strongly narrowed medially; ventral ridge projecting; LAEA deeply convex; GS cupped within G margins, subquadrate base projecting apically; very large recurved rami extending beyond G margins; setae long black, not short apically, dense tufts of long, thickened setae medially, directed basally, very long thin setae continuing laterally; H large, subquadrate in lateral view, distinctly projecting. Epiphallus 1.4 × neck width; with apical margins inturned forming projecting rounded lobes.

Female.

Unknown.

This species is named as a noun in apposition after the three-year, multimillion dollar Bush Blitz program that organised and funded the survey on Charles Darwin Reserve, Karara, Lochada and Kadji Kadji Pastoral Leases in Western Australia on which this species was collected. The core focus of the Bush Blitz program is to document the plants and animals in hundreds of properties across Australia’s National Reserve System, and on nature discovery – identifying and describing new species of plants and animals. The Bush Blitz program also funded the survey in western New South Wales and Queensland on which Palirika culgoafloodplainensis sp. n. was collected (ABRS BB 2009/23887) and funded the description of these three species (ABRS BB TTG209-06).

(Fig. 11). Larrpana bushblitz sp. n. has only been collected from Karara Pastoral Lease, 213 km ESE of Geraldton in Western Australia.

On collection, this species appeared similar to the two male specimens of Larrpana zwicki collected only near Windorah (Lambkin et al. 2003) and phylogenetic analysis (Figs 2–3) indicates a close relationship between the two.

Munjua erugata Lambkin & Yeates, 2003: 795.

Wing with medial hyaline band not linear and narrowing apically, apical infuscated band not meeting posterior wing margin more broadly than medial hyaline band. Gonocoxae deeply narrowed medially, broadly indented basally, with tufts of thickened setae ventromedially, H projecting but not forming a finger-like extension; AE short; EP with medioventral process above AE; very long AAES reaching G margins; EJA racquet-shaped, very long. Sperm pump short with unpigmented papillae, apical endplate simple with thin processes; thick-walled round SR with distinct basal bulb.

Included species: Munjua erugata Lambkin & Yeates 2003, Munjua lepidokingi Lambkin & Yeates 2003, Munjua paralutea Lambkin & Paramonov 2003.

See reference to the rediagnosis of the genus Munjua in the phylogenetic results.

Munjua trigona Lambkin & Yeates, 2003: 804.

Wing with medial hyaline band linear and narrowing apically, apical infuscated band meeting posterior wing margin twice breadth of medial hyaline band (Fig. 9A, B). Gonocoxae deeply narrowed medially, broadly indented basally, with tufts of thickened setae ventromedially, H projecting forming finger-like extension (Figs 9E, 10F); AE short; EP with medioventral process above AE; very long AAES reaching G margins; EJA racquet-shaped, very long (Fig. 10). Sperm pump short with unpigmented papillae, apical endplate simple with thin processes; thick-walled round SR with no basal bulb (Fig. 9F–H).

The name for the genus Ngalki is from the aboriginal term ngalki for “little finger” from the Ngiyampaa language spoken in much of central New South Wales (Donaldson 1994), referring to the diagnostic character of the male genitalia for this genus, and is treated as neutral. This follows the tradition set in Lambkin et al. (2003), of using appropriate aboriginal terms for the names of new genera of Australian exoprosopines.

Included species: Munjua trigona Lambkin & Yeates, 2003

See reference to the erection of the genus Ngalki in the phylogenetic results.

Paratypes. New South Wales: 1♂, Round Hill Nature Reserve, 27 Dec 1976, G. Daniels, GDCB Reg # 14199, K 253709; 1♀, Round Hill Nature Reserve, same, GDCB Reg # 17925, K 253717 (AM). Victoria: 1♀, Wyperfield Nat Park, 7 Dec 1976, G. Daniels, GDCB Reg # 14163, K 253707; 3♂, Wyperfield Nat Park, 8 Dec 1976, G. Daniels, GDCB Reg # 17924, #14164, # 17923, K 253720, (PS1936) K 253702, K 253712 (AM).

New South Wales: 1♀, Round Hill area, 24–25 Nov 1991, A. Sundholm, [dissected], PS1935, K 289927 (AM). Western Australia: 1♂, Fraser Range, 8 Nov 1977, A. Atkins, [dissected], GDCB Reg # 14165, PS1934, K 253698 (AM).

Large dark flies (wing length 15-20 mm), wings as in Figure 9B, dark with narrow, linear, medial hyaline band; long, finger-like apically-directed projection on hypandrium (Figs 9E, 10F). Laterothoracic stripe creamy-white. Broad white scale band on T₃, T_4–5 with black scales, T_6–7 with white scales. Epandrium with long golden setae; SES joined medially. Epiphallus with short medial projection. Female with no BB between pump and pale, square SR.

Male. Head (Fig. 9C). Face and frons red with reddish-yellow scales, black setae longest below deep frontal depression. Antennal scape 3 × length of pedicel, red; pedicel red; PP 3.5 × length of pedicel, black with reddish pruinescence; BSM dark reddish-brown, 3.5 × length of pedicel, expanded apically; ASM short, blunt (Fig. 9D). Narrow line of creamy-white scales on posterior margin of eye.

Thorax. Collar yellow, with tips of Ma darker, reddish. Laterothoracic stripe broad creamy-white, distinct. Scutum black with long hair-like reddish-brown scales, sparse white flattened scales posteromedially. Pleural vestiture dark-red with mauve iridescence; admixed dark-red and black Ma on PE and AN; long scales at base of wing with mauve iridescence. Anepimeral setae admixed dark-red and black. Scales on APA yellow. Plumula and TR hairs creamy yellow. LT with black Ma, red dorsally. Scutellum red with scales yellowish-red, setae black, sparse long white scale fringe on posterior margin. Legs red with dark reddish-brown scales. Pulvilli chisel-like wedges, less than a half length of mid- and hind-tarsal claws. Halter knob dark reddish-brown, with yellow apical edge. Wing (Fig. 9B). R₄₊₅ with abrupt bend basally, cup closed at wing margin, or narrowly open. Widened base of C with dark, reddish-brown scales, paler brown scales posteriorly. M₂ very sinuous, width of m₁ at wing margin < 1/2 width of m₂. Wing pattern (Fig. 9A, B) black, with broad infuscated band following R proximal to i-r₁, obliquely through 1st r₂₊₃, r₅ and m₁ to meet wing margin in m₂; no infuscation in 2nd r₂₊₃. Hyaline band very narrow, linear, from dc through m₂ basally, apex of cua, cup and anal cells. Squama with reddish-yellow scales.

Abdomen (Fig. 9B). Integument with large red areas laterally, leaving black medial band; T₂ with black medial band broad basally, width > 1/3 width of the tergite, tapering sharply apically; T_3–4 with black medial band < 1/4 width, black apical band; T_5–7 with red areas laterally < 1/4 width. T₁ with Ma white, reddish-brown scales medially. T₂ with dense long cream hairs anterolaterally, dark reddish-brown scales, some white scales laterally. Broad white scale band on T₃, interrupted medially, dark reddish-brown scales anteromedially, black scales posteromedially. T_4–5 with black scales, T_6–7 with white scales. Sternites red; S_2–3 and S_4–5 basally with dense white scales and dense long, fine white hairs; S_4–5 apically with dark reddish-brown scales, S_6–7 with black scales, black setae. Genitalia (Figs 9E, 10). Epandrium red with basal flange short and broad; setae black, long golden setae apically; SES joined medially. Gonocoxae red, strongly narrowed medially; setae black, short apically, medially with thick tufts of basally directed setae, long setae laterally around apex of H; distinct ventral ridge; LAEA deeply convex, extending past G margins; GS cupped within G margins, large subquadrate base with slight projection apically; large recurved R; H crescent-shaped, laterally delimited by swollen and expanded G, laterally subrectangular, with distinct large, blunt finger-like apical projection. Epiphallus long, not expanded apically; with medial projection.

Female. Same as male. Genitalia (Fig. 9F–H). Dorsal T₈ A short, entire; T₁₀ with 4 pairs of short, thick AC spines; apical endplate with long thin processes; basal endplate with thick processes; long unpigmented papillae, no BB, narrow ring between pump and lightly pigmented, square SR.

In Lambkin et al. (2003), the name trigona given to this species was derived from the Greek trigonas “triangular” This was the name the late Sergei Paramonov gave to this species in his unpublished manuscript, and was used to honour his extensive work on Australian bombyliids. With the transfer to Ngalki, the specific emendation requires adjustment, and becomes trigonium to reflect the neutral gender of the new genus-group name.

This species has been collected in the southern Australian Bassian region, from semi-arid and arid mallee areas.

The finger-like projection on the H (Figs 9E, 10F) in the males of Ngalki trigonium is apparent without dissection and, together with the unusual wing pattern, allows easy identification.