Borboroides lindsayae, 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 : 169-171

Borboroides lindsayae n.sp.

Figs 47–50

Material examined. HOLOTYPE.?, Australian Capital Territory: Mount Gingera [Brindabella Range], 14.iv.1968, D.H.C. ( ANIC). Mounted on micropin through polyporus . PARATYPES. Australian Capital Territory: 3!!, same data as holotype ( ANIC) ; 2??, Bull’s Head, near Canberra , April 1968, D.H.C. ( AM, ANIC) . Victoria: 8??, 1!, Mount Donna Buang , near summit [Warburton district], April 2003, B.J.D., D.K.M. ( AM, MV) .

Description (male, female). Large fly for the genus, resembling B. tonnoiri in most characters except as indicated below.

Coloration. Head tawny-yellow; vertex of postfrons and upper part of occiput suffused with brown, sometimes faintly so in males, more intensely browned in females; postfrons entirely pruinescent, without distinctly shining zones. Thorax with dorsal surface predominantly blackish with thick covering of brown pruinescence; region of humeral callus, notopleuron, and sometimes lateral parts of scutellum tawny in males, these parts usually darker in females; pleura tawny with some brown suffusion in males, largely brown in females. Legs tawny, femora often brown to blackish distally, more consistently so in females; tarsi browned distally. Abdomen largely blackish, with grey to brown pruinescence on tergites; epandrium largely tawny.

Head. Postfrons slightly less narrowly projecting anteriorly than in B. tonnoiri ; height of cheek 0.51–0.62 of height of eye; anterior fronto-orbital bristle usually distinctly more than half as long as posterior one, inclined outwards and slightly forwards.Antenna: segment 3 markedly less elongate than in B. tonnoiri and in male less nearly parallel-sided.

Thorax. Intradorsocentral setulae in two pairs of rows, the outer row usually nearly as developed as paramedian row, latter row usually extended posteriorly well beyond level of posterior dorsocentral bristle. Legs with armature and male modifications as in B. tonnoiri , except hind femur with two longitudinally aligned anterodorsal bristles (in addition to slightly developed subapical one). Wing: apical section of vein 4 1.4–2.1× as long as penultimate section.

Abdomen. Preabdomen generally resembling that of B. tonnoiri ; in female, sternite 5 nearly twice as long as sternite 4; in male, sternite 5 almost crescentic, but attenuated medially, setulose only on lateral parts. Male postabdomen: protandrial complex asymmetrical anteriorly, somewhat as in B. tonnoiri ; sternite 8 moderately elongate, with numerous setulae laterally and near posterodorsal margin; epandrium inflated, large for overall size of insect, with numerous moderate-sized setulae, generally distributed except in region of deep, extensive anteroventral bridge; surstylus more elongate than B. tonnoiri , parallel-sided beyond the slightly broadened base, with fine anterior setulae including long ones near base and small distal ones, without stouter setulae or spines, distal margin rounded, but with several shallow, inwardly directed serrations; prehypandrial membrane relatively restricted in area, deeply cupped so as to be scarcely visible in normal anteroventral view (somewhat as in B. tonnoiri and B. donaldi ), with dense groups of mostly very short microtrichia on visible surface; hypandrium consisting of pair of broad lateral plates and broad posteromedian plate, all of complex structure (some details not visible in Fig. 45); gonite short, rounded, bearing both long and minute fine-tipped setulae, the former not as long and numerous as in B. tonnoiri , on medial side process attached to hypandrium by subconical support which bears medially directed sclerotized spine; aedeagus approximately symmetrical, without paired processes; basiphallus short, sclerotized; distiphallus rather short and stout, but not distally inflated, with much of surface scabrous with dense, minute, mostly subconical tubercles; aedeagal apodeme apparently short and little sclerotized; cerci very broad, meeting on median line, each broadly truncate, with moderate setulae anteriorly and few very long submarginal posterior setulae or mollisetae, not forming a conspicuous brush and much less dense than in B. tonnoiri ( Fig. 50).

Dimensions. Total length,? 2.9–3.7 mm,! 2.9–3.5 mm; length of thorax,? 1.4–1.6 mm,! 1.4–1.6 mm; length of wing,? 4.2–4.7 mm,! 4.3–5.1 mm.

Distribution. Australian Capital Territory: Brindabella Range. Victoria: Yarra Valley district. The species has been rarely collected, but possibly occurs more widely on or near mountain tops of southeastern Australia.

Notes

Among the relatively large-sized species included in the stewarti group, Borboroides lindsayae , together with B. tonnoiri , is recognized by having the ground colour of the mesoscutum black to dark brown (except towards lateral margins), overlaid by grey or brown pruinescence, the mesopleuron very largely dull-pruinescent, and the mid tibia without short seriate ventral bristles in either sex. Males of these species differ from other species of the group in the many conspicuously long ventral mollisetae on the mid tibia, and from species other than B. donaldi in the deeply recessed hypandrial complex. In B. lindsayae the anterior fronto-orbital bristle is inclined outwards and forwards, and is generally more than half as long as the posterior one; in B. tonnoiri the anterior fronto-orbital is inclined outwards and backwards and is not more than half as long as the posterior one. In fresh specimens of B. lindsayae the thoracic dorsum is dark brown, rather than grey-black as in B. tonnoiri . In males of B. lindsayae the surstylus is more elongate than in B. tonnoiri and the cercus is much less densely setulosemollisetose. The female of B. lindsayae has a large shining, almost smooth zone on abdominal sternite 5; in B. tonnoiri this sternite is entirely densely pruinescent.

A single male specimen ( Mount Donna Buang , Victoria, April 1963, AM) is possibly an aberrant diminutive individual of B. lindsayae or even a hybrid. The cercus and surstylus appear to agree with this species, so far as they can be interpreted without special preparation, but the anterior fronto-orbital bristle is reclinate, the mid tibia has no mollisetae but has a large subapical ventral spur, and the hind femur has only one anteroventral bristle .

Borboroides lindsayae has not been taken by us at wombat dung. The specimens collected at Mount Donna Buang by B.J.D. and D.K.M. were on wallaby dung, probably from Macropus rufogriseus (Desmarest) .

The specific epithet refers to Suzanne M. Lindsay who carried out the electron microscopy for this and other projects.