Borboroides gorodkovi, McAlpine, 2007

McAlpine, DK, 2007, Review of the Borboroidini or Wombat Flies (Diptera: Heteromyzidae), with Reconsideration of the Status of Families Heleomyzidae and Sphaeroceridae, and Descriptions of Femoral Gland-baskets, Records of the Australian Museum 59, pp. 143-219 : 193-195

Borboroides gorodkovi n.sp.

Figs 9, 10, 102–107

Material examined. HOLOTYPE.?, Tasmania: The Neck, Bruny Island [“Penguin Rookery” on some maps, c. 43°17'S 147°21'E], 16–18.iii.2005, B.J.D., D.K.M. ( AM K219754 ). Mounted on card point . PARATYPES. Tasmania: 26??, 18!!, similar data to holotype, but some collected Dec.1987, D.K.M. ( AM, ANIC, USNM, TDPI) .

Other material. New South Wales: 1!, Goonoo State Forest , 5 mi. [c. 8 km] S of Mendooran, May 1970, D.K.M., G.A.H., G.D. ( AM) . South Australia: 1!, Pine Dams on Myrtle Springs Station , 24 mi. [c. 39 km] WNW of Leigh Creek, June 1964, R.O.C. ( AM) . Western Australia: 1?, Stirling National Park , “54–mile post” [Stirling Ranges], Oct. 1970, D.H.C. ( ANIC) ; 2!!, 28 km W of Yalgoo , Sept. 1981, G.A.H. ( AM) .

Description (male, female). Small grey-black fly, somewhat resembling B. shippi .

Coloration. Predominant ground-colour black. Occiput and c. posterior half of postfrons black with dense dark grey pruinescence; c. anterior half of postfrons typically yellowish-tawny, entirely pruinescent; face greyish tawny; cheek typically extensively yellow to tawny-yellow, becoming blackish posteriorly, with yellowish-pruinescent zone along lower margin. Antenna: segments 1 and 2 tawnybrown; segment 3 typically bicoloured, tawny-yellow and brown. Prelabrum blackish with grey pruinescence; palpus typically yellow or tawny-yellow. Thorax with dense dark grey pruinescence on most of surface; mesopleuron with large shining to subshining black zone on central and anteroventral part, broadly grey-pruinescent on posterior and dorsal margins, narrowly but distinctly grey-pruinescent on margin of fore-coxal foramen; sternopleuron with subshining central zone; hypopleuron shining brown-black, except for grey pruinescence near anterior margin and on small posterodorsal zone, but posterior half otherwise bare, glossy. Fore coxa tawny; other coxae brownish; femora blackish, with dense grey pruinescence and, at each extremity, a small yellowish zone; tibiae grey-brown, yellowish apically and more broadly so basally; tarsi tawny-yellow, becoming dark grey distally. Wing membrane tinged with yellowish brown; veins yellowish, becoming slightly darker apically. Halter with tawny base and pale yellow capitellum.Abdomen black; preabdominal tergites and sternites very largely grey-brown pruinescent, but sternite 1 extensively shining and, in female, tergites 5 and 6 each with lateral subshining black zone.

Head much higher than long; eye subcircular or, in profile, slightly higher than long; postfrons with rather long setulae on anterior half mostly inclined forwards and mesad, those along orbits mostly reclinate; height of cheek 0.44–0.58 of height of eye; ocellar and both fronto-orbital bristles almost equally long, the two latter directed outwards, the anterior one more strongly so. Antenna rather short; segment 3 rounded, slightly decumbent, very slightly longer than deep; arista distinctly shorter than greatest diameter of eye. Prelabrum in female broad, of moderate depth, in male narrower, more removed from lower margin of face; palpus moderately short and slender.

Thorax stout; intradorsal setulae coarse, in c. six irregular rows; mesopleuron with several coarse posterior setulae; dorsocentral bristles well developed, three pairs present; prescutellar acrostichal and posterior intra-alar bristles well developed. Fore femur with several long posterodorsal and posteroventral bristles, mainly on distal half, without anteroventral bristles; mid femur with a series of few rather short anterior bristles; hind femur usually with one preapical dorsal bristle; fore tibia often with one or two small preapical dorsal bristles; mid tibia with large bristles as described for B. fimbria , subapical ventral spur long and stout; hind tibia with large preapical dorsal bristle and slender, curved subapical spur c. 1.5× as long as greatest diameter of tibia. Wing generally typical of the atra group (as described for B. fimbria ); within second costal cell, subcosta sclerotized for at least 0.7 of length of that cell; apical section of vein 4 c. 2.6–3.4× as long as penultimate section; penultimate section of vein 5 less strongly curved than in other species of atra group so that discal cell is narrower; anal cell with posterodistal angle not acute; distal section of vein 6 slightly less than twice as long as anal crossvein.

Abdomen. Sternite 1 broader than in most other species of atra group, well sclerotized and not narrowed medially; in male sternites 2 to 5 all very broad, so that pleural membrane is more restricted than in other species of atra group; in female these sternites less broad, as in related species. Male postabdomen: tergite 6 small, fully sclerotized; spiracle 6 present in pleural membrane; spiracle 7 apparently absent; compound protandrial sclerite relatively stout, curved, tapered posteriorly, almost symmetrical; sternite 6 forming dark sclerotized band right round ventral surface, with pair of elongate anterior lobes on ventral part; sternite 8 extensively sclerotized ventrally, with pair of prominent posterior condyles, setulose, with usually one pair of enlarged posterolateral setulae; epandrium broad, with relatively narrow anteroventral bridge, numerous large, stout setulae laterally, and smaller setulae posterodorsally; surstylus stoutly rod-like, incurved, with numerous large and small anterior setulae, with small fine-tipped and truncated setulae on inner surface just beyond mid-length, and numerous stout, spinescent, mostly blunt setulae on inner surface near apex; process of lateral hypandrial sclerite slightly compressed, knob-like, with group of mainly posterior setulae, one much larger than others; aedeagus stout; basiphallus with dark sclerite covering at least posterior surface; distiphallus broadly bilo hing beyond epandrial bridge; cercus very broad, with distal margin transverse (the pair together approximately as wide as epandrium), with moderately short setulae and one longer posterior setula. Female postabdomen: cercus elongate, not thickened distally.

Dimensions. Total length,? 1.4–1.9 mm,! 1.8–2.0 mm; length of thorax,? 0.67–0.88 mm,! 0.88–1.0 mm; length of wing,? 1.6–1.9 mm,! 1.7–2.0 mm.

Distribution. New South Wales: Central West division. Tasmania: Bruny Island. South Australia: Flinders Ranges. Western Australia: Stirling Ranges; Central West division.

Notes

Borboroides gorodkovi is fairly typical of the atra group and particularly resembles those species with more extensively pruinescent mesopleuron and no glossy zone in front of the anterior ocellus (e.g., B. shippi and B. corynetes ). It differs from these in the presence of three pairs of dorsocentral bristles (usually one or two pairs in the other species), the longer subapical spur of the hind tibia, the less curved section of vein 5 bordering the discal cell, the well marked but narrow zone of dense pruinescence along the margin of the fore coxal foramen, the largely glossy posterior section of the hypopleuron, and particularly the details of the surstylus and cercus of the male.

More than any other species of the atra group, B. gorodkovi resembles B. dayi and B. staniochi , which may conceivably constitute a close outgroup to the atra group, but these two species have the anterior fronto-orbital bristle reduced, the subapical spur of the hind tibia short or vestigial, vein 6 longer, and the hind femur without gland-baskets. It is possible that B. gorodkovi represents a sub-basal branch of the atra group, arising after the separation of B. menura .

Part of the evidence that Australian mainland populations are conspecific with the Tasmanian type population is the similarity of the male genitalia of the specimen from Stirling National Park (Western Australia) to those of the Tasmanian specimens. However , this male specimen differs strongly from all the Tasmanian specimens in having no yellow zone on the postfrons, the cheek entirely blackish in ground colour, and the palpus dark brown. Males are not available from other mainland localities. The females from Myrtle Springs (South Australia) and Yalgoo district (Western Australia) resemble the type population in coloration, while that from Goonoo State Forest (New South Wales) is intermediate (probably faded—collected May 1970). Until better material is available, I cannot be certain that all specimens from mainland localities are referable to B. gorodkovi .

The habitat on Bruny Island is on dunes densely penetrated by burrows of penguins ( Eudyptula minor ) and shearwaters ( Puffinus sp. ) A short distance from this “rookery” in forest on sand, Borboroides gorodkovi could not be found, though B. fimbria and B. atra were present. The specimen from Goonoo State Forest was collected from an old, drying kangaroo carcass.

The specific epithet refers to Kiril B. Gorodkov, who has made an outstanding contribution to knowledge of the Heteromyzidae .