Borboroides bulberti, 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 : 205-206

Borboroides bulberti n.sp.

Figs 130–139

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 K219759 ). Mounted on card point . PARATYPES. New South Wales: 20??, 11!!, Mount Wilson, March, May , Sept., Oct., April 2002 –2004, D.K.M. ( AM, ANIC, USNM) ; 1?, 7!!, Putty Road, 41 km N of Colo R. bridge, c. 220 m, May, June , Sept. 2002 –2003, D.K.M. ( AM) ; 2??, 1!, Colo Heights, 33°21'S 150°44'E, May 2002, D.K.M. ( AM) .

Other material (localities only given). Victoria: 7 km SW of Bruthen ( AM); near [northern foot of] Mount Juliet, 9 km E of Healesville ( MV).

Description (male, female). Very small blackish fly, resembling B. fimbria and agreeing with description of that species, except as indicated below.

Coloration mostly as given for B. fimbria . Postfrons extensively grey-pruinescent, with subtriangular median glossy zone immediately in front of median ocellus, extending c. halfway to ptilinal suture or slightly less, but with subshining zone lateral to ocelli smaller and less distinct, thinly pruinescent as well as ridged; area between fronto-orbital bristles and median glossy zone almost entirely pruinescent. Abdomen of female: tergite 5 pruinescent anteriorly, without median grey-pruinescent stripe, broadly glossy across whole posterior part; each lateral plate of tergites 6 and 7 with glossy brown to black posterior zone.

Head. Height of cheek 0.23–0.35 of height of eye.

Thorax largely as given for B. fimbria . Subapical anteroventral spur of hind tibia variable, up to c. half as long as maximum diameter of tibia, sometimes undeveloped. Wing: apical section of vein 4 c. 3.0–4.0× as long as penultimate section; posterodistal angle of anal cell usually somewhat acute.

Abdomen. Sternite 5 divided into two transversely oval sclerites in male, undivided in female. Male postabdomen: tergite 6 reduced to pair of vestigial sclerites; sternite 6 largely symmetrical, with annular anterior marginal thickening duplicated anteroventrally to give appearance of a supernumerary sternite; epandrium slightly shorter and stouter than in B. fimbria , with numerous scattered moderately short setulae; anteroventral bridge occupying at least half of length of epandrium; prehypandrial membrane with few short comb-like rows of minute subconical microtrichia; surstylus with very broad gibbous strongly setulose basal expansion, beyond this more slender and strongly curved so that apex is directed anteriorly (apices of pair lying closely parallel when cerci are infolded), apical part obtuse, with spinules on inner surface; pair of hollow internal hypandrial sclerites present but shorter than in B. merzi ; lateral hypandrial process somewhat resembling that of B. fimbria ; inner gonite apparently absent (contrast B. merzi ); aedeagus a little more elongate than in B. fimbria and B. merzi ; basiphallus on anterior surface of aedeagus little developed, on posterior surface with pair of basally broad, distally attenuated sclerites; distiphallus with dense covering of closely packed filaments; filaments on anterior surface mostly arising from or near narrowly sclerotized lateral margin, thence directed inwards so that those of each 206 Records of the Australian Museum (2007) Vol. 59 side tend to meet along anterior median line; filaments on posterior surface mostly distally to distolaterally directed, more basal ones radiating from median basal zone; cercus rather large, broadly ovate, with narrowly obtuse apex, its outer surface dull-pruinescent, except along glossy medial margin, and with scattered medium-sized setulae, on inner (or anterior) surface with strong irregularly placed setulae. Female postabdomen: tergites 6 and 7 divided in two by median desclerotization, each sclerite pruinescent anteriorly, glossy posteriorly; cercus shorter than in B. fimbria and B. merzi , not apically thickened.

Dimensions. Total length,? 1.4–1.5 mm,! 1.5–1.7 mm; length of thorax,? 0.63–0.69 mm,! 0.66–0.81 mm; length of wing,? 1.7–1.8 mm,! 1.7–2.1 mm.

Distribution. New South Wales: Blue Mountains and Colo River district. Victoria: probably widely distributed in eastern half of state (few records).

Notes

Borboroides bulberti resembles B. fimbria , B. merzi , and B. acumen in the yellow capitellum of the halter, and shining frontal zone in front of the ocelli. The males differ from other species in the large, compressed, ovate-triangular cercus with only short setulae ( Fig. 133) and the broad-based surstylus with slender, anteriorly flexed apex. Otherwise, it is distinguished by having the median shining zone of the postfrons rather broad, but the non-pruinescent shining zone on each side of the anterior ocellus is smaller and less distinct. The subapical spur of the hind tibia ( Fig. 132) is often distinct but always shorter than in B. fimbria .

All specimens of B. bulberti were collected around wombat dung baits, probably mainly in natural wombat habitats.

The specific epithet refers to Matthew Bulbert of the Australian Museum, whose photographic work aided this project.