Helosciomyza bickeli, McAlpine, 2012

McAlpine, David K., 2012, Notes and Descriptions of Australian Helosciomyzidae or Comb-winged flies (Diptera: Schizophora), Records of the Australian Museum 64 (1), pp. 51-70 : 60-63

Helosciomyza bickeli n.sp.

Figs 2 , 15

Helosciomyza ferruginea Hendel. –Steyskal & Knutson, 1979:734–736 (misidentifications; fig. 16 probably refers to H. steyskali , fig. 18 refers to H. bickeli ); Barnes, 1981: 56–57 (in part, misidentification; fig. 13 does not represent H. bickeli ).

Type material. Holotype ♂. New South Wales : “Mooraback”, Werrikimbe National Park, 31°09'S 152°13'E, 980 m, 6.xii.1986, D. J.B. ( AM K264288 ). Double-mounted on micro-pin through polyporus, postabdomen in micro-vial on pin . Paratypes. New South Wales : 1♂, Gibraltar Range National Park , Feb. 1982, B.J.D. ( AM) ; 9♂♂, Mount Banda Banda , 1200 m, Dec. 1986, D. J.B. ( AM, ANIC) ; 1♂, 2♀♀, Cobcroft Creek , Werrikimbe, Dec. 1986, D. J.B. ( AM) .

Other material examined (localities only given). Queensland: 7 miles (c. 11 km) up Mount Lewis Road, Julatten district ( ANIC); Mount Edith, N of Tinaroo Dam ( ANIC); Sluice Creek, near Millaa Millaa ( ANIC); Paluma ( AM); Eurimbula, Miriam Vale district ( AM, QM); Summer Creek, near Kenilworth ( AM); Mount Tenison Woods, near Mount Glorious ( AM); Bundaroo Creek, Conondale Range ( AM); Killarney ( UQIC); Binna Burra, Lamington National Park ( AM). New South Wales: Mount Warning, near Murwillumbah ( AM); Falbrook, 30 km NNE of Singleton ( AM); Barrington River, W of Gloucester ( ANIC); Wallaroo State Forest, N of Raymond Terrace ( ANIC); Myall Lakes ( AM); Myall River ( AM); Mount Wilson ( AM); 8 km S of Mount Wilson ( AM); Roberts Creek, near East Kurrajong ( AM); Narrabeen, near Sydney ( AM); Willoughby, near Sydney ( AM); Oxford Falls, near Sydney ( AM, ANIC); Sydney ( AM); Royal National Park ( AM); Otford ( AM). Tasmania: Frodshams Pass, near Mount Wedge ( AM).

Description (male, female). Medium-sized brownishvariegated fly of medium build, with almost unmarked wing; most parts pruinescent and non-shining.

Coloration (dry, clean, non-greasy specimens). Head rufous to pale tawny dorsally with pale grey pruinescence on median zone enclosing postvertical and ocellar bristles and extending narrowly well in front of anterior ocellus and usually more than half distance from ocellus to ptilinal suture; fronto-orbital plates greyish pruinescent; frontoorbital margins narrowly more silvery pruinescent; upper occiput extensively grey-pruinescent, usually with tawny spot between each outer vertical bristle and eye margin; face and cheeks pale tawny-yellow with whitish pruinescence.Antenna largely tawny; segment 3 tawny-orange with at most very faint brown suffusion not forming distinct dorsal or distal zone; arista largely brown, tawny at extreme base. Prelabrum and palpus tawny-yellow, latter with black setulae and bristles. Mesoscutum orange-tawny, with broadly creamy-grey lateral margins and five additional pale grey longitudinal stripes— median and paired dorsocentral and sublateral; sublateral stripe narrow, not extending in front of suture and usually connected to dorsocentral stripe anteriorly and posteriorly; scutellum orange-tawny with pale pruinescent zone on each side dorsally and usually pale pruinescent anterior margin; humeral callus whitish-pruinescent dorsally, tawny ventrally; pleura extensively whitish-pruinescent; upper proepimeron (behind spiracle) tawny, the tawny zone extending broadly and obliquely across upper mesopleuron to membranous cleft, but leaving small posterodorsal whitish zone on mesopleuron; remainder of pleura largely orange-tawny with whitish pruinescence, changing in appearance with angle of view. Legs mainly orange-tawny; fore femur with subapical brown mark, often more distinct on anterior than on posterior surface, with no brown zone on basal half; other femora with more distinct subapical brown to blackish mark; tibiae usually with brown to blackish distal zone, usually least developed on mid tibia; hind tibia usually with sub-basal brown zone, sometimes indistinguishable; fore and hind tarsi with segments 4 and 5 brown, segment 3 usually partly brown; mid tarsus with at least segment 5 brown. Wing: largely hyaline, with diffuse brown spot in subcostal cell, small brown spot on anterior crossvein, and indistinct brownish suffusion on discal crossvein. Halter pale yellow.Abdomen tawny-brown to yellowish, not showing consistent pattern in dried specimens; all tergites thinly pruinescent, tergite 5 not less so than preceding tergites.

Head slightly higher than long; cheek c. 0.29–0.34 as high as eye, with scattered small setulae often tending to form a single peristomial series anteriorly; face with rather narrow, rounded median carina; the following bristles present: inner and outer vertical, long subparallel to slightly convergent postverticals, ocellar, two fronto-orbitals, anterior one shorter, usually three postgenals, posterior one situated higher than anterior one. Antenna: segment 6 pubescent on whole length, with many hairs almost as long as its basal diameter. Palpus moderately large, setulose, with some distal setulae enlarged or thickened.

Thorax. Mesoscutum with many non-seriate setulae, generally distributed except towards lateral margins; humeral callus with few setulae; scutellum approximately flat dorsally, without setulae; mesopleuron bare; sternopleuron ventrally in male with many long coarse setulae, in female these much less developed, leaving irregularly transverse series of major bristles well differentiated in front of coxae; pteropleuron (anepimeron) without setulae; hypopleuron (metepisternum) with minute downwardly directed setulae, varying in precise distribution and in number (two to twelve in examined specimens); the following, mostly large, thoracic bristles present: two dorsocentrals, prescutellar acrostichal, presutural, intra-alar, postalar, humeral, 1 + 1 notopleurals, proepisternal (propleural), small proepimeral (stigmatal), two upper sternopleurals. Fore femur with a series of large dorsal bristles, and on distal half, with posteroventral bristles better developed in female than in male, often with many fine almost erect ventral setulae, often including mollisetae, in male, these setulae fewer and shorter in female; mid femur with irregularly placed group of enlarged anterior setulae just beyond mid-length, one large posterior preapical bristle and, in male only, a comb-like series of posteroventral setulae just before apex; hind femur with one or two anterodorsal bristles near distal quarter, in male with many fine erect ventral setulae, in female these shorter and fewer; fore tibia with one preapical dorsal bristle; mid tibia with one preapical dorsal bristle and c. five terminal spurs of various sizes; hind tibia with long typical preapical dorsal bristle, one equally stout anterodorsal bristle between this and apex, and two apical ventral spurs of different sizes; hind basitarsus shorter and broader in male than in female, with many setulae, but lacking basal ventral cluster of short back setulae as seen in H. australica ; fore and hind tarsal segments 2, 3 and 4 of male with median ventral scopulae (pads of very fine, dense pubescence), these undeveloped in female; segment 4 of each tarsus in male very short and relatively broad, almost crescentic, in female little longer, subtriangular. Wing: costa with large, well spaced anterior spines (sensu Hackman & Väisänen, 1985), progressively smaller distally, bordering second costal, subcostal, and marginal cells; separate series of anterodorsal spaced spines absent; vein 1 consistently without setulae on ventral surface; distal section of vein 6 extending to margin, thick and well sclerotized on c. basal quarter of length, abruptly narrowed and weakened beyond.

Abdomen. Pleural membrane without setulae in region of spiracle 1; sternite 1 somewhat sclerotized, divided medially, setulose, better developed in male than in female; sternite 5 of male with compact zone of dense short, rather stout setulae on each side of bare median zone, setulae elsewhere on sternite 5 sparse and longer; sternite 5 of female without such differentiated zones, with scattered setulae slightly larger laterally than centrally. Male postabdomen: posterior margin of epandrium almost straight in profile, bordered by elongate basal plate of surstylus (visible in posterior view), internally without anterior process; surstylus ( Fig. 15 ) slightly broadened basally, with almost transverse basal articular margin and prominent setulose posterior marginal tubercle arising distinctly beyond base, main distal part almost hatchet-blade shaped, rather narrowed before distal expansion, which is broadly rounded anteriorly, subacutely angular postero-apically, with narrowly inflexed distal margin, patch of microtrichia on outer surface (present in H. steyskali , H. subacuta and related species) virtually absent; basal surstylar process absent; aedeagus complex, with elongate obtuse epiphallus (spinus); aedeagal apodeme large, deep, bilaterally compressed; cerci elongate ovate, leaflike, joined by membrane for c. half length of each. Female abdomen: spiracles 1 to 7 located in pleural membrane and distinctly removed from margins of tergites; tergite 5 and sternite 5 large and unmodified; postabdomen simple. not very extensile; tergite 6 and sternite 6 smaller than preceding sclerites; segment 7 narrower, with sternite divided longitudinally into two setulose plates; tergite 8 forming compact sclerite; sternite 8 elongate, setulose; apparent tergite 9 and sternite 9 small but distinct, setulose; cerci separate, subcylindrical with some apical setulae long and fine; spermathecae three, subspherical, with black cuticular lining, two of them attached to end of a common duct.

Dimensions. Total length, ♂ 5.4–5.9 mm, ♀ 6.4–6.5 mm; length of thorax, ♂ 2.6–3.0 mm, ♀ 3.1–3.2 mm; length of wing, ♂ 5.5–6.0 mm, ♀ 6.2–6.3 mm.

Distribution. Queensland: east coast and nearby ranges as far north as Julatten district. New South Wales: coast and nearby ranges. Tasmania: mountainous areas of south— single record. This is the only helosciomyzid species known from the Australian tropics.

Notes

Helosciomyza bickeli and H. fuscinevris are the only Australian helosciomyzids with a setulose sternite 1. They also share the presence of minute hypopleural setulae. Helosciomyza bickeli differs from H. fuscinevris in the absence of a brown zone on antennal segment 3, the absence of pteropleural setulae, and the differently shaped surstylus. The shape of the surstylus of H. bickeli somewhat resembles that of H. steyskali (compare Figs 15 , 23 ), but is narrower than in that species, with much less pubescence on the outer surface. Helosciomyza steyskali further differs from H. bickeli in the absence of setulae on the hypopleuron and on the more reduced sternite 1, also the extensive brown zone on the anterior surface of the fore femur, which extends on to the basal third. The status of the little known Tasmanian population needs further investigation in view of its wide isolation from northern populations.

The specific epithet refers to Daniel J. Bickel, who collected significant material and has supported this study.

Figures

Figures 1–3. Left hind tibia, anterior view of apical part. (1) Neosciomyza peckorum. (2) Helosciomyza bickeli. (3) Cobergius vittatus. as, apical ventral spurs; pd, preapical dorsal bristle; sa, subapical anterior bristle.

Figures 14–18. (14) Neosciomyza peckorum (Boyd River), terminal part of epandrium and associated structures, anterior view, right anterior epandrial process cut away for clarity, scale = 0.5 mm. (15) Helosciomyza bickeli (Cobcroft Creek), left surstylus, outer view, scale = 0.2 mm. (16) H. fuscinevris (Clarence, near Lithgow), left surstylus, outer view. (17) same specimen, right surstylus, outer view. (18) H. subacuta (Wannon River), left surstylus, outer view. Figs 15–18 all same scale. aep, anterior epandrial process; bsp, basal surstylar process; c, cercus; ep, epandrium; ss, surstylus.

Figures 19–26.(19) Helosciomyza steyskali, protandrogram.(20) H.australica, epandrium and associated structures, posterior view, semi diagrammatic, setulae omitted. (21) H. neboissi (Pelion), left surstylus, outer view, scale = 0.2 mm. (22). H. australica (Picton Lakes), left surstylus, outer view. (23). H. steyskali (Boyd River), left surstylus, outer view. (24). H. obliqua (Mount Donna Buang), left surstylus, outer view. (25). H. driesseni (holotype), left surstylus, outer view. (26). H. macalpinei (holotype), left surstylus, outer view. Figs 21–26 all to same scale. c, cercus; ep, epandrium; pbf, posterobasal foot of surstylus; ss, surstylus; s5–s8, sternites 5 to 8; t5, t6, tergites 5 and 6.