Borboroides menura, 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 : 190-193

Borboroides menura n.sp.

Figs 7, 8, 97–101

Material examined. HOLOTYPE.?, New South Wales: Kanangra-Boyd National Park , 1 km N of Boyd River [or Morong Creek] bridge, 1200 m, 22.ix.2005, D.K.M. ( AM K219753 ). Near dead chook. Mounted on card point . PARATYPES. New South Wales: 9??, 2!!, same data as holotype, but some Oct. 2005 ( AM, USNM) . Australian Capital Territory: 1?, Picadilly Circus [Brindabella Range, 35°22'S 148°49'E], 800 m, April 1978, S.B.P., J.K.-P. ( ANIC) .

Description (male, female). Small, slightly elongate, largely black fly, slightly larger than other species of atra group.

Coloration. Head largely black; face, anterior part of cheek, and anterior part of postfrons yellow in male, tawnybrown in female; postfrons pruinescent on rather more than anterior half, with large bare, shining to subshining zone on each side of ocelli and quite small subtriangular glossy zone in front of anterior ocellus. Antenna tawny-yellow, with arista and dorsal suffusion on segment 3 brown. Prelabrum brown in male, black in female; palpus yellowish brown to dark brown. Thorax normally black (fading to brown in old specimens); mesoscutum and scutellum evenly pruinescent; mesopleuron pruinescent on c. posterior half and on dorsal margin; sternopleuron pruinescent on dorsal margin; hypopleuron pruinescent both anteriorly and posteriorly. Legs largely blackish brown; fore coxa partly tawny-brown. Wing unmarked. Halter tawny, with pale yellow capitellum. Abdominal tergites black with brown pruinescence; tergite 5 of female shining, with generally distributed sparse pruinescence.

Head. Eye c. as long as high or slightly longer; postfrons with numerous short setulae anteriorly; height of cheek c. 0.33–0.47 of height of eye; ocellar bristle slightly longer than posterior fronto-orbital bristle; anterior fronto-orbital bristle c. as long as posterior one, directed outwards. Antenna: segment 3 slightly longer than deep; arista c. as long as greatest diameter of eye. Prelabrum small and shallow in male, larger and more prominent in female; palpus moderately short.

Thorax. Mesoscutum with intradorsocentral setulae on anterior half in two pairs of rows, with few in outer row; mesopleuron with c. four setulae on or near posterior margin; dorsocentral bristles two, length of anterior one c. 0.8 of that of posterior one; posterior intra-alar bristle moderately curved, slightly diverging from vein 4 apically; apical section of vein 4 2.1–2.3 times as long as penultimate section; anterior crossvein meeting vein 4 well before mid-length of discal cell; basal crossvein oblique; anal crossvein oblique, almost straight, but curved at anterior end; distal section of vein 6 as long as anal crossvein or somewhat longer.

Abdomen. Sternite 1 well sclerotized and undivided. Male: tergite 5 nearly as large as tergite 4; sternites 4 and 5 short, very broad, medially attenuated. Male postabdomen: tergite 6 narrowly transverse, undivided; compound protandrial sclerite rather short for atra group, anteriorly strongly asymmetrical, with sternite 6 extensively developed on left side and part of ventral surface, but not on right side; sternite 7 sclerotized; sternite 8 bridged ventrally, with bridge contracted on right side; epandrium, including its anteroventral bridge, asymmetrical ( Fig. 99); surstylus with two lobes, one directed distally, one directed posteriorly, both lobes with few setulae, distal lobe, in addition, heavily spinulose on inner surface, some of larger spinules distally compressed and bearing two to four rounded apical teeth; basal section of surstylus densely pubescent on inner surface; prehypandrial membrane rugose, without microtrichia; hypandrium with pair of narrowly bifid posteriorly directed lobes; a pair of prominent elongate processes arising from prehypandrial membrane where it borders on hypandrium, each minutely bifid and bearing two fine hair-like apical projections; basiphallus very short, sclerotized at least on posterior surface; distiphallus more elongate, consisting of three main irregularly bulbous sections, not strongly sclerotized but its basal and mid sections with many subparallel denticulate sclerotized ridges; distal section of aedeagus largely smooth, transparent, bearing beaklike terminal process with apical gonopore; cerci basally articulated with epandrium, their bases fused to form a stout body bearing a diversity of setulae and, on its posterodistal surface, a large process, forked from just beyond its base to form pair of very long, compressed, distally slightly spatulate lobes, which remain exposed when genital complex is infolded. Female postabdomen: segments 6 and 7 not attenuated, with undivided tergites and sternites; cercus not clavate.

Dimensions. Total length,? 1.7–2.1 mm,! 2.1–2.3 mm; length of thorax,? 0.74–0.87 mm,! 0.83–0.95 mm; length of wing,? 2.3–2.5 mm,! 2.7–2.8 mm.

Distribution. New South Wales: highlands—few records. Australian Capital Territory: only known from highlands near Canberra.

Notes

Borboroides menura agrees with most species of the atra group in the long, outwardly directed anterior fronto-orbital bristle, the distribution of pruinescence on the mesopleuron and hypopleuron, the setulose mesopleuron, the short distal section of vein 6, and the well sclerotized undivided abdominal sternite 1. Within this group it is distinguished by its slightly larger size, quite large additional dorsocentral bristle near mid-length of mesoscutum, the different gland complexes on the hind femur, the strong distal curvature of vein 1, the more elongate anal and discal cells so that the discal crossvein is located well beyond mid-length of wing, and, in the male, the development of sternite 6 on the left side only and the much larger, strangely shaped cercus. These conditions for sternite 6 and the femoral gland complexes and the proportions of the anal and discal cells are probably more plesiomorphic than in all other species of the atra group. Borboroides menura therefore appears to be a phylogenetically basal taxon within this group. The more oblique anal crossvein is probably also plesiomorphic for the group, but the condition is approached in B. gorodkovi , which, with a little variation, has venation intermediate between that of B. menura and other species of the atra group. Absence of the usual very short microtrichia on the prehypandrial membrane of the male is a probable autapomorphy for B. menura , though it is repeated in B. parva , which appears not to be closely related.

The specimen from Picadilly Circus is labelled “carrion trap.” The other specimens were collected on or near old carcasses of domestic fowl.

The specific epithet (Greek, mighty tail) is the generic name of the lyre-bird, in reference to the similarity of the male cercal lobes to the major male tail feathers of that sympatric Australian bird.