Borboroides perkinsi, 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 : 176-178

Borboroides perkinsi n.sp.

Figs 18, 19, 61–63

Material examined. HOLOTYPE.?, New South Wales: 5 miles [“ 5 m. ”, i.e. c. 8 km] S of Monga, Braidwood district , 8.v.1968, D.H.C., Z.R.L. ( ANIC). On micropin through polyporus . PARATYPES. New South Wales: 9??, 11!!, 3, 4, and 5 mi. [c. 5, 6, and 8 km] S of Monga , May 1968, D.H.C., Z.R.L. ( AM, ANIC) ; 1?, 2!!, Mount Wilson, Blue Mountains, May , June 2002 –2004, D.K.M. ( AM) ; 1!, Kanangra-Boyd National Park , 1 km N of Boyd River Bridge, Sept. 2005, D.K.M. ( AM) . Australian Capital Territory: 1?, 1!, Black Mountain, Canberra , May 1980, D.H.C. ( ANIC) ; 1!, Picadilly Circus, Brindabella Range , 800 m, April 1978, S.B.P., J.K-P. ( ANIC) .

Other material (localities only given). Queensland: “Nat. Park” [i.e. Lamington National Park, Macpherson Range] ( UQ). New South Wales: Wright’s Lookout, New England National Park ( AM). Victoria: Mallacoota National Park ( ANIC); Mount Donna Buang, near Warburton ( AM); Cement Creek, near Warburton ( ANIC).

Description (male, female). Moderately small, slightly elongate, partly shining, dark brownish fly.

Coloration (older specimens often paler than indicated). Head tawny-yellow; posterior part of postfrons and upper occiput brown to blackish; postfrons pruinescent anteriorly, more shining posteriorly; face glabrous and glossy on most of surface. Antenna largely tawny-brown; segment 3 predominantly dark brown; segment 5 yellow; segment 6 white or creamy-white. Prelabrum yellow to tawny-yellow; palpus dark brown to tawny brown. Thorax largely shining black to dark brown; mesoscutum and scutellum thinly pruinescent; lateral margin of mesoscutum and propleuron tawny-yellow. Legs largely brown to tawny brown; coxae yellowish; fore tarsus dark brown. Wing: veins brown; membrane with slight yellow-brown tinge. Halter pale tawny with creamy-white capitellum. Abdomen brown; in male, anterior part of protandrium, posterior part of epandrium, and cercus yellow; in female, cercus pale yellow.

Head c. as long as high, slightly angular in profile at junction of postfrons and face; postfrons weakly setulose anteriorly; face receding below on much of surface, but with slightly projecting lower margin; height of cheek 0.22–0.33 of height of eye; ocellar bristle slightly longer than posterior fronto-orbital; anterior fronto-orbital bristle absent or scarcely differentiated from setulae; postvertical bristle small. Antenna: segment 3 porrect, longer than deep, slightly longer in male than in female; arista with pubescence longer and denser than in other Borboroides spp. Prelabrum moderately large and prominent in female, smaller, less prominent, and separated from face by membranous band in male.

Thorax. Mesoscutum with two or three small setulae towards each lateral margin, but rest of surface, including intradorsocentral region, quite without setulae; mesopleuron with two or three posterior setulae; dorsocentral bristles three, anterior one at least 0.7 of length of posterior one, situated well in front of transverse suture; presutural and anterior notopleural bristles very long; humeral and posterior notopleural bristles small; posterior intra-alar bristle distinct; one sternopleural bristle present. Legs more elongate than in most other Borboroides spp. ; fore basitarsus relatively slender; hind basitarsus at least half as long as hind tibia, generally longer in males; fore femur with two or three long posteroventral bristles and c. three long posterodorsal bristles, without anteroventral bristles; mid femur with c. three anterior bristles on its distal third; hind femur with large anterodorsal preapical bristle and one or two small subapical bristles; mid tibia with two large preapical dorsal bristles and a small anterior bristle slightly basad of these, also with two unequal subapical ventral spurs and vestigial subapical anterior spur; hind tibia without subapical spur. Wing rather elongate, slightly narrowed basally, with relatively narrow alula; costal setulae on region of costal cells all small; costa noticeably weakened beyond humeral crossvein; subcosta with slight indication of weakening near same level; anterior crossvein meeting vein 4 well before mid-length of discal cell; vein 2 on much of length almost parallel with vein 3, diverging at apical extremity; apical section of vein 4 1.6–2.0× as long as penultimate section; basal crossvein oblique; penultimate section of vein 5 almost straight; discal and anal cells narrow (particularly relative to those of atra group); apical section of vein 6 slightly curved towards posterior margin, extending about two thirds distance from anal crossvein to margin, distally terminating abruptly.

Abdomen. Tergite 5 shorter than tergite 4 in both sexes; sternite 1 reduced, sclerotized only at sides; in male, sternite 5 shorter than sternite 4. Male postabdomen: epandrium only slightly asymmetrical; sternite 6 almost encircling postabdomen, less developed on right side, on ventral part symmetrical with pair of narrow anterior extensions as in B. atra ; segment 8 elongate, curved, slightly clavate posteriorly, extensively sclerotized ventrally, with lateral ridge on each side of anterior half and scattered setulae; epandrium elongate, but with large rounded median hump on anteroventral bridge, with numerous moderately short setulae and one large bristle on each side of anteroventral hump; surstylus divided into two lobes from a little beyond base, which shows no definite line of articulation with margin of surstylus; outer lobe broad, truncate, incurved distally, with several large setulae on outer surface; inner lobe of surstylus long, slender, with three short, stout spinules on distal part; hypandrium with two pairs of processes; anterior process (gonite) setulose and with two long terminal bristles, inner bristle minutely curled at apex, outer bristle with preterminal nodule; posterior process of hypandrium densely scabrous with covering of short denticles and minute microtrichia; aedeagus largely sclerotized, somewhat T-shaped, with basal shaft and anterior and posterior distal extensions; basal shaft c. as long as cercus, with pair of densely minutely microtrichose ridges on lateral margins of anterior face, and beyond these a pair of largely smooth lamellae; anterior extension elongate, apparently with terminal gonopore; posterior extension of aedeagus with tuft of long pubescence near base of distal surface, otherwise smooth, with rounded, solid apex; aedeagus apodeme elongate; cercus ovate, distally rounded, with scattered setulae on posterior (outer) surface, on anterior surface with a short, rounded sub-basal lobe bearing short, stout setulae on its margin. Female postabdomen: tergites and sternites of segments 6 and 7 only moderately reduced in size; cercus moderately short.

Dimensions. Total length,? 2.1–2.7 mm,! 2.4–2.8 mm; length of thorax,? 0.99–1.10 mm,! 1.0– 1.2 mm; length of wing,? 3.0– 3.4 mm,! 3.2–3.6 mm.

Distribution. Queensland (southeastern border district) to eastern Victoria —cooler districts.

Notes

Borboroides perkinsi is a morphologically isolated species in the genus Borboroides , though by no means the only such species. The following conditions in B. perkinsi distinguish it from all other Borboroides spp : the face is largely glossy and devoid of pruinescence (other species have the face entirely thinly to densely pruinescent); the arista is pale, with segment 6 white or almost so (other species have the arista strongly brown-pigmented); the dorsocentral bristles are all long, with the arrangement 1+2 (in no other species are there three such long dorsocentrals, and none has the arrangement 1+2); mesoscutal setulae are quite absent (all other species have at least the central anterior part of the mesoscutum with numerous setulae); the hind basitarsus is at least half as long as the hind tibia (less than half as long as hind tibia in other species). The five above character states are all probable autapomorphies for B. perkinsi and do not indicate what its closest relatives may be. Borboroides perkinsi also shows marked specific peculiarities of the male postabdomen, but numerous other species of the genus have their own unique conditions. We may note for B. perkinsi the following features: anteroventral bridge of epandrium with large rounded hump; hypandrium with pair of densely scabrous processes; aedeagus T-shaped in lateral view.

In B. perkinsi the nature of the glandular region of the hind femur, the proportions of wing veins and cells, and the sexual dimorphism in antennal segment 3 agree with the stewarti group, but the abruptly truncated vein 6 and presence of mesopleural setulae disagree with this group. The reduced, bipartite abdominal sternite 1 disagrees with the atra group, but is in general agreement with other groups. As agreement of B. perkinsi with the stewarti group is ambiguous and could be due to plesiomorphies, I place it in the monotypic perkinsi group.

Borboroides perkinsi has occasionally been collected at both wombat dung and carrion.

The specific epithet refers to F. Athol Perkins, formerly of University of Queensland, who collected this species in Queensland in 1935 and later made specimens available for study .