Borboroides helenae, 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 : 183-186

Borboroides helenae n.sp.

Figs 4–6, 80–84

Material examined. HOLOTYPE.?, New South Wales : Mount Wilson [Blue Mountains; Waterfall Reserve, c. 900 m, 33°31'S 150°23'E], 6–7.v.2002, D.K.M. ( AM K219750 ). Mounted on card point . PARATYPES. New South Wales : 4??, 2!!, Mount Wilson, May, Aug. 2002, D.K.M. ( AM, BM) ; 2!!, Putty Road , 41 km N of Colo River bridge, May, June, 2002–2003, D.K.M. ( AM) ; 2??, Colo Heights, May 2002, D.K.M. ( AM) ; 6??, 6!!, Kanangra Road , 14.2 km S of Oberon – Jenolan road junction, April 2002, B.J.D., D.K.M. ( AM, USNM) ; 12??, 10!!, Boyd River crossing, Kanangra-Boyd National Park, April 2002 –2004, B.J.D., D.K.M. ( AM, TDPI) ; 4??, 1!, 5 m (iles) [c. 8 km] S of Monga , Braidwood district, May 1968, D.H.C., Z.R.L. ( ANIC) . Australian Capital Territory : 4??, 1!, Mount Coree, April 1968, D.H.C. ( ANIC) .

Other material (localities only given). Victoria: 7 km S of turnoff to Cape Conran from Prince’s Highway, Orbost district ( AM); Providence Ponds Reserve, 32 km W of Bairnsdale ( AM); 11 km E of Warburton ( AM, MV); Mount Donna Buang, near Warburton ( AM, MV); Dom Dom Saddle, 17 km NE of Healesville ( AM); Fernshaw, 6 mi [c. 10 km] NE of Healesville ( AM); near Mount Juliet, 9 km E of Healesville ( AM, CNC, BM). Tasmania: Ferntree, near Hobart ( AM).

Description (male, female). Small largely black, partly shining fly with unmarked wing.

Coloration. Head largely black; postfrons orange-fulvous anteriorly, with large subtriangular glossy blackish zone from vertex to mid-anterior region, outside this zone greyishpruinescent; face tawny-yellow, pruinescent; cheek tawny, subshining. Antenna tawny to yellowish, segment 3 partly blackish. Male: prelabrum tawny-yellow; palpus pale yellow. Female: prelabrum tawny-brown; palpus dark grey-brown. Thorax black; mesoscutum and scutellum with almost uniform covering of greyish pruinescence; mesopleuron shining black, with small zone of yellow-grey pruinescence on upper margin, none on posterior margin; sternopleuron largely shining black with very little pruinescence near coxa; hypopleuron shining brown-black, with little yellowish anterodorsal pruinescence in male, with additional zone of greyish pruinescence posteriorly, narrowly separated from posterior margin. Legs largely brown to blackish; fore coxa, trochanter and base of femur yellowish; mid tarsus yellowish brown on variable extent. Wing membrane tinged with brownish yellow; veins yellowish brown. Halter yellowish brown, with grey-brown capitellum. Abdomen black, largely shining; tergites 1–3 with broad grey-pruinescent median zones; in male epandrial sclerite brown-pruinescent; epandrium predominantly glossy; in female tergite 6 with some brown pruinescence medially.

Head higher than long; eye slightly higher than long; postfrons with setulae on anterior half mostly inclined forwards and mesad, some tending to form pair of imperfectly differentiated anteriorly convergent series (somewhat resembling interfrontal bristles of sphaerocerines); face concave; height of cheek 0.27–0.33 of height of eye; ocellar bristle longer than major fronto-orbital; posterior fronto-orbital reclinate and slightly inclined outwards; anterior fronto-orbital not or only slightly differentiated from reclinate orbital setulae. Antenna: segment 3 shortoval, almost horizontal; arista distinctly longer than greatest diameter of eye, with numerous short hairs extending to apex. Prelabrum small in male, larger and moderately prominent in female; palpus moderately short and slender.

Thorax moderately stout; intradorsocentral in four rows; scutellum without setulae; mesopleuron with several setulae, mainly on upper posterior quarter; the following bristles present: humeral, small presutural, 1+1 notopleurals, supraalar, postalar, posterior intra-alar, one larger and two small dorsocentrals, two pairs of scutellars, rather large posterior sternopleural and one or two smaller anterior ones. Fore femur with five or more long posteroventral bristles and few posterodorsal bristles, without anteroventral bristles; mid femur slightly curved, more so in male, with a series of of thorax.

seven or more rather short anterior bristles and, in male only, a variable number of long fine ventral bristles or hairs; hind femur with one preapical dorsal bristle; fore tibia lacking smooth longitudinal ridges as described for male of B. doreenae , with slightly differentiated preapical dorsal bristle; mid tibia with pair of approximated preapical dorsal bristles, usually two anterior bristles basad of these, one anteroventral and one posterior subapical spur, in male only numerous long ventral mollisetae; in female only a long apical ventral spur; hind tibia with moderately long preapical dorsal bristle and at most vestigial anteroventral subapical spur. Wing: costa with setulae on second costal cell more than half as long as width of that cell; section of subcosta on second basal cell sclerotized for c. two thirds length of that cell; anterior crossvein meeting vein 4 near or slightly beyond mid-length of discal cell; vein 2 distally almost parallel with vein 3 or slightly diverging; apical section of vein 4 = 3.4–4.3 times as long as penultimate section; basal crossvein slightly oblique, not aligned with penultimate section of vein 5; curvature of vein 5 along discal cell relatively slight; anal crossvein oblique for most of length, curved anteriorly; distal section of vein 6 slightly more than twice as long as anal crossvein.

Abdomen. Sternite 1 divided into pair of widely separated lateral sclerites; additional minute sclerotized transverse bar present on median line between sternite 1 and sternite 2; tergite 5 much shorter than tergite 4 in male, only slightly shorter in female. Male postabdomen: tergite 5 joined to tergite 6 by a pigmented band on each side; sternite 5 of moderate size, narrowed medially, joined to protandrial sternite complex by a pigmented zone on each side; tergite 6 small, divided in two; protandrial sternite complex slender, approximately symmetrical, with anterior band of sternite 6 equally dark and sclerotized on each side, without ventrolateral angle or prominence on each side; spiracle 7 vestigial, apparently closed; epandrium large and inflated, as long as preabdomen, usually appearing pointed in dried specimens through partial collapse, with very broad anteroventral bridge in front of hypandrium; surstylus broad, truncate distally, notched posteriorly at base, on inner surface with setulae anteriorly and many blunt spinules posteriorly; anteromedian part of prehypandrial membrane with many comb-like groups of short microtrichia; hypandrial structure very complex ( Fig. 84), with three pairs of diversely shaped processes, of which only the setulose deeply bilobed gonite is obviously homologous with any structure in other species of Borboroides ; posterior median dark blade-like process or epiphallus extensively attached to base of aedeagus; aedeagus without clear division into basiphallus and distiphallus, clavate, well sclerotized, with terminal gonopore, lateral tubercles having basally directed points, and roughening near gonopore which suggests flat scales; aedeagal apodeme long, apparently free; prehypandrial membrane enclosing a lightly pigmented, probably soft, irregularly U-shaped strip; cerci short, not compressed, well separated, articulated with epandrium, with short setulae and few longer terminal mollisetae. Female postabdomen: tergite 6 short, transverse, undivided.

Dimensions. Total length,? 2.1–2.3 mm,! 2.3–2.6 mm; length of thorax,? 0.96–1.1 mm,! 0.99–1.2 mm; length of wing,? 2.3–2.7 mm,! 2.5–2.8 mm.

Distribution. New South Wales: mainly highlands; also Colo River district. Australian Capital Territory: Brindabella Range. Victoria: widely distributed in eastern half of state. Tasmania: Hobart district, single record.

Notes

Among the species with only one well-developed frontoorbital bristle and relatively short discal cell ( staniochi and helenae groups), B. helenae is distinguished by the more extensively glossy thoracic pleura, there being no obvious pruinescence on the posterior margin of the mesopleuron and the convex anterior part of the pteropleuron; it is the only species of the genus in which the prothoracic spiracle is almost completely surrounded by bare, glossy cuticle ( Fig. 81). It shares with B. doreenae the large glossy area on the postfrons surrounding the ocelli and the distinctive type of gland-baskets on the hind femur, but lacks other peculiarities listed for that species. The male is conspicuously different from that of B. doreenae and species of the staniochi group in having many long ventral mollisetae on the mid tibia and a massive genital capsule (epandrial complex). Also the presence of three pairs of hypandrial processes, one of which is deeply bilobed, is unique in the genus. The morphology suggests that B. helenae is phylogenetically somewhat isolated, but, as in the case of B. doreenae , I do not think that placing the species in its own monotypic group would clarify its relationships.

Borboroides helenae has most frequently been collected around wombat dung baits.

The specific epithet refers to Helen M. Smith, in recognition of her valuable help in the preparation of this paper.