Borboroides musica, 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 : 164-167

Borboroides musica n.sp.

Figs 15–17, 22–25, 36, 38–41, 166

Material examined. HOLOTYPE.?, New South Wales: Mount Wilson [Blue Mountains; Waterfall Reserve, c. 900 m, 33°31'S 150°23'E], 24–25.iii.2002, D.K.M. ( AM K219744 ). Mounted on micropin through polyporus . PARATYPES. New South Wales: 48??, 24!!, Mount Wilson, March, April , May , June , Oct. 1957 –2005, D.K.M. ( AM, ANIC) ; 111??, 51!!, Kanangra Road, 9.2 and 14.2 km S of Oberon – Jenolan Road junction, April 2002 –2004, B.J.D., D.K.M. ( AM, BM, CNC, MV, NAT, TAU, USNM) ; 2??, 1!, Boyd River crossing, Kanangra-Boyd National Park , April 2002 –2004, B.J.D., D.K.M. ( AM) ; 2??, Rudy’s Road turnoff, 15 km N of Jenolan, April 2004, B.J.D. ( AM) ; 1!, Black Springs fossicking area, Vulcan State Forest , 27 km SSW of Oberon, May 2003, B.J.D. ( AM) .

Other material (localities only given). New South Wales: Putty Road, 41 km N of Colo River bridge [Yengo National Park] ( AM); 2 mi. [c. 3 km] SW of Tumorrama [Tumut district] ( AM); Monga [Braidwood district] ( ANIC); 4 and 5 mi. S of Monga ( ANIC); Mongarlowe River, Clyde Mountain ( ANIC); Kunama, Batlow district ( ANIC); Rutherford Creek, Brown Mountain ( ANIC). Australian Capital Territory: Mount Coree ( ANIC); Bull’s Head ( ANIC); Tidbinbilla ( AM); Honeysuckle Creek ( ANIC); Blundells Creek ( ANIC). Victoria: 10 km S of Bonang ( ANIC); road to Mount Magnet, Wilson’s Promontory ( AM); 13 mi [c. 21 km] W of Matlock ( AM); Warburton ( AM); near summit of Mount Donna Buang, near Warburton ( AM, MV); Fernshaw, near Healesville ( AM, MV); Mayer’s Creek, near Healesville ( ANIC); Kinglake ( ANIC).

Description (male, female). Strongly resembling B. stewarti in many respects; agreeing with description given for that species, except as indicated below.

Coloration generally resembling that of B. stewarti . Occipital region of head often with less dark suffusion than in B. stewarti .

Head. Height of cheek 0.41–0.54 of height of eye; anterior fronto-orbital bristle only slightly smaller than posterior one, proclinate and often slightly inclined outwards. Antennal segment 3 c. 1.3–1.4× as long as deep, generally very slightly more elongate in male than in female.

Thorax rather slender for stewarti group; intradorsocentral setulae few, in one pair of rows; dorsocentral bristles three, mid one scarcely shorter than anterior one, sometimes a quite small additional bristle at level of transverse suture. Fore leg with unique stridulatory modification (visible only at higher magnification, see description above); mid femur usually more noticeably curved in male than in female, with anterior bristles but no posteroventral bristles in either sex; hind femur with a simple series of ventral, rather than posteroventral bristles in male only, and no posteroventral excavation; mid tibia essentially as described for B. stewarti ; hind tibia with quite small but distinct subapical ventral spur, in male without strong curvature or other modification except that ventral setulae on distal part are numerous and conspicuously erect (less conspicuous and more nearly decumbent in female). Wing elongate, slightly narrowed basally across anal region; subcosta weakly sclerotized and slightly pigmented distally; apical section of vein 4 1.6–1.9× as long as penultimate section; distal section of vein 6 long, but generally less curved distally than in B. stewarti .

Abdomen. In male, tergite 5 broad, but much shorter than tergite 4, with relatively few bristles/setulae; sternite 5 sclerotized on whole width, but setulose mainly at sides; in female, tergite 5 less than half as wide as tergite 4, almost parallel sided, with few long posterior setulae. Male postabdomen: tergite 6 vestigial; spiracle 6 present in membrane on each side; sternite 6 developed on left side only; spiracle 7 present on each side, left one enclosed within posterior lobe of sternite 6; segment 8 rather stout, only slightly narrowed posteriorly, with few large anterolateral setulae and smaller posterodorsal setulae; epandrium subovoid, approximately symmetrical, with ventral transverse ridge on anterior part of anteroventral bridge; surstylus somewhat rounded in outline, slightly broader than long, of much simpler form than that of B. stewarti , with thickened incurved distal margin, with numerous moderatesized setulae on outer surface and mainly long, thick, spinescent, inwardly directed setulae on anterodistal margin, and with densely spinose posterodistal prominence; gonite small, depressedly subovate (in Fig. 40 each of pair seen from different angle as result of pressure from cover slip), with relatively few strong setulae; basiphallus short, with pair of somewhat approximated short, sharp-edged anterior lamellae, but no long lateral processes (as are present in B. stewarti ); distiphallus bulbous, with somewhat narrowed apical part bearing gonopore on anterior subapical surface, surface of bulbous part strongly scabrous, with very dense small tubercles varying from rounded to subconical; aedeagal apodeme long and slender; cerci well separated at bases, each short, rounded, not compressed, with brush of very dense mollisetae on convex distal surface, some c. as long as epandrium, and with anterior fascicle of finger-like setiferous processes, largely concealed in lateral view; proctiger not prominent, located in groove. Female postabdomen slender; cercus more slender than in B. stewarti .

Dimensions. Total length,? 2.4–3.0 mm,! 2.0– 3.6 mm; length of thorax,? 0.95–1.3 mm,! 1.1–1.5 mm; length of wing,? 3.2–4.0 mm,! 3.4–4.6 mm.

Distribution. New South Wales: mainly cooler districts, from Colo River district southwards. Australian Capital Territory: Canberra district. Eastern Victoria.

Notes

Borboroides musica agrees with B. stewarti in its relatively pale colouring, the thorax being largely tawny with some darker brown markings. Other species of the stewarti group have the thorax predominantly deep brown to black, except in very faded specimens. Borboroides musica differs from B. stewarti in the well-developed proclinate anterior frontoorbital bristle (much smaller and reclinate in B. stewarti ), in the male by the absence of posteroventral bristles on the mid femur, the almost straight hind tibia, and the very differently shaped and armed surstylus and cercus, in the female by the narrow, parallel-sided abdominal tergite 5. The stridulatory organ on the foreleg ( Figs 22–25) is peculiar to this species, but can only readily be discerned with CLM or SEM.

Most of our recently collected specimens of B. musica were obtained on or near wombat dung.

The specific epithet is a Latin adjective, musical, in reference to the stridulatory organ.