Borboroides doreenae, 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 : 186-187

Borboroides doreenae n.sp.

Figs 1–3, 85–87

Material examined. HOLOTYPE.!, New South Wales: Putty Road , 41 km N of Colo River bridge, 33°11'S 150°41'E, c. 220 m [Yengo National Park], 6.vi.2002, D.K.M. ( AM K219751 ). Mounted on card point . PARATYPES. New South Wales: 3??, 10!!, same locality as holotype, May, June , Sept. 2002 –2004, D.K.M. ( AM, ANIC, USNM) .

Description (male, female). Very small, largely black fly with slight but distinctive wing markings; agreeing with description given for B. staniochi except as indicated below.

Coloration. Postfrons largely shining to subshining black to brown-black, dark-pruinescent between and in immediate vicinity of ocelli and narrowly along orbital margins, but not in front of anterior ocellus; face densely greyish to yellowish brown-pruinescent, paler in male. Antenna orange-tawny; segment 3 dark brown on dorsal and distal parts. Palpus pale cream to yellow in male, black to dark brown in female. Mesopleuron with pruinescence almost as extensive as in B. staniochi , but less dense; sternopleuron glossy with small zones of pruinescence near centre and on ventral part. Fore coxa yellow; other coxae brownish yellow; femora and tibiae brownish, yellowish to variable extent basally; fore tarsus with segment 1 brown, sometimes narrowly yellowish at apex, segments 2 to 4 pale yellowish, segment 5 tawny or tawny-yellow, other tarsi yellow to tawny-yellow, with segment 5 and sometimes segment 1 tawny-brown. Wing membrane tinged with smoky brown, with one milky white basal and anal crossveins, and another at extreme base; veins elsewhere brown. Abdominal tergites largely shining or subshining black, thinly pruinescent.

Head. Outline of eye tending slightly oval, its surface with sparse, inconspicuous ommatrichia; face slightly raised on median line, concave in profile; height of cheek 0.41–0.54 of height of eye; posterior fronto-orbital bristle strongly curved laterad; anterior fronto-orbital bristle not differentiated from adjacent setulae. Antenna: segment 3 short-ovoid, broadly rounded distally; length of arista subequal to or shorter than greatest diameter of eye. Prelabrum in female moderately developed but not prominent, separated from face by membranous band, in male very small and remote from lower margin of face; palpus short.

Thorax. Supra-alar and posterior intra-alar bristles rather small; anterior sternopleural bristle very small. Fore femur with all posteroventral bristles short, rather poorly differentiated, in male only with a regular, comb-like series of more numerous short, thickened anteroventral bristles; mid femur with anterior bristles few and irregular; hind femur with basket glands as described above; fore tibia, in male only, with two smooth, low but rather sharp longitudinal ridges, an anteroventral one occupying approximately basal third of tibia, and a slightly more prominent, more ventrally placed ridge occupying much of remainder of tibial length; mid tibia with paired preapical dorsal bristles longer than in B. staniochi , with the following subapical spurs in both sexes: anterior, ventral, no posterior one; hind tibia without distinct preapical dorsal bristle and apical anteroventral spur. Wing: subcosta sclerotized for 0.8 of length of second costal cell (i.e. distinctly longer than in B. staniochi ), but weakened at humeral position; anterior crossvein meeting vein 4 slightly before mid-length of discal cell; apical section of vein 4 c. 3.2–4.3× as long as penultimate section; posterior crossvein moderately oblique to almost transverse; distal section of vein 6 extending slightly more than half distance from anal crossvein to margin.

Abdomen. Male postabdomen: sternite 5 nearly as broad as tergite 5, with each posterolateral angle strongly produced, not narrowed medially; tergite 6 sclerotized, undivided, rather small; protandrium stout, little longer than tergite 5, with anteroventral sclerotization asymmetrical, but sternite 6 forming complete, symmetrical, darkly sclerotized ventral band; sternite 8 with extensive ventral sclerotization; surstylus slender, slightly incurved, not widened distally, with few minute setulae and two to five small tooth-like spinules at apex; hypandrium with sclerotized plate on each side, each plate with few setulae of very diverse sizes, and a sharp, curved posterolateral point (but otherwise no indication of hypandrial process or gonite), and compact lateral extension touching margin of epandrium; aedeagus short, compact, largely membranous, but flanked by pair of large, black, sclerotized hooks, their apices extending well beyond membranous part; aedeagal apodeme rather stout, of moderate length, directed towards dorsal wall of epandrium; cerci rather long, ovoid, obtuse, extensively irregularly setulose, joined by membrane for more than half their length, but without sclerotized connecting bar. Female postabdomen: cercus shorter and broader than in B. staniochi .

Dimensions. Total length,? 1.4–1.9 mm,! 1.5–2.2 mm; length of thorax,? 0.67–0.85 mm,! 0.66–0.96 mm; length of wing,? 1.6–1.9 mm,! 1.5–2.3 mm.

Distribution. New South Wales: lowlands of Colo River district, between Blue Mountains and Hunter Valley. Only known from the type locality.

Notes

Borboroides doreenae has the general superficial characters of the staniochi and helenae groups, particularly in the venation and the reduction of the anterior fronto-orbital bristle. It is readily distinguished from other species of these groups by the absence of distinct posteroventral bristles on the fore femur, the bicoloured fore tarsus, and the milky white spot covering the distal ends of the second basal and anal cells. In the male, the hypandrial structure is unique in the genus, as it lacks any well defined paired processes, and no other Borboroides species has an even remotely similar aedeagus. Because of limited available material, I have not been able to illustrate male postabdominal structures in the detail desired. I justify inclusion of this species in the same group as B. helenae mainly by the similarity in the hind femoral gland-baskets and glossy zones on the postfrons and lower propleuron, despite the divergence in some other significant characters.

All specimens were taken around wombat dung baits.