Ngalki trigonium (Lambkin & Yeates) Lambkin, Christine L. & Bartlett, Justin S., 2011

Lambkin, Christine L. & Bartlett, Justin S., 2011, Bush Blitz aids description of three new species and a new genus of Australian beeflies (Diptera, Bombyliidae, Exoprosopini), ZooKeys 150, pp. 231-280 : 247-248

Ngalki trigonium (Lambkin & Yeates) comb. n. Figs 23910

Munjua trigona Lambkin & Yeates, 2003: 804.

Material examined.

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).

Other material.

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).

Rediagnosis.

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, T4-5 with black scales, T6-7 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.

Redescription.

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; T3-4 with black medial band <1/4 width, black apical band; T5-7 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. T4-5 with black scales, T6-7 with white scales. Sternites red; S2-3 and S4-5 basally with dense white scales and dense long, fine white hairs; S4-5 apically with dark reddish-brown scales, S6-7 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. 9 F–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.

Etymology.

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.

Distribution.

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

Comments.

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.