Helosciomyza australica Steyskal, 1978

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 : 64

Helosciomyza australica Steyskal

Figs 20, 22

Helosciomyza australica Steyskal , in Steyskal & Knutson, 1979: 735, figs 14, 15, 25–27, 34–37; Barnes, 1981: 56, figs 11, 12.

Type material (re-examined D.K.M.). Holotype ♂. New South Wales: Picton Lakes [Thirlmere Lakes], “Bred larva”, 2.xi.1936, anon. ( AM K264619 ) . Cleared abdomen in microvial on same pin. Allotype ♀. Similar data to holotype, “#5”, 8.xi.1936; puparium (also “#5”) in capsule on separate pin ( AM) . Paratypes. 2♂♂, 3♀♀, similar data to holotype, apparent emergence dates 1.xi.1936 and 2.xi.1936 ( AM) .

Other material (identification confirmed D.K.M.). New South Wales: Careel Bay, Avalon ( Casuarina swamp, land now cleared and reclaimed), June 1962, D.K.M. ( AM); 1♂ , Otford (area now a residential zone), Nov. 1962, D.K.M. ( AM) .

Female specimens from more southern localities (whence no confirmatory males). New South Wales: Swan Lakes, near Sussex Inlet ( AM); Tantawangalo Mountain, near Candelo ( AM). Victoria: Mount Donna Buang, near summit, Warburton district ( AM). Tasmania: near Russell Falls, Mount Field National Park ( AM).

Distribution. New South Wales: lowlands of Sydney district, between c. 33°39'S and 34°14'S. I have seen no specimens from the Sydney district collected after 1962. Possibly also more southern districts of New South Wales, Victoria, and Tasmania.

Notes

The male has the surstylus distinctively shaped and quite without pruinescence in the two specimens viewed under high magnification ( Fig. 22 ), and a distinctive dense, nonlinear cluster of short, thick black setulae ventrally at the base of the hind basitarsus, but no such diagnostic structures have been found in the female. Among the species with extensively infuscated antennal segment 3 and no setulae on the hypopleuron and abdominal sternite 1, H. australica differs from H. obliqua and H. macalpinei in having the fore femur entirely tawny-yellow on both anterior and posterior surfaces, except for the subapical brown mark, and foretarsal segment 3 is only slightly browned distally. These conditions alone may be inadequate as a reliable diagnostic indicator, especially as only females have been obtained in the apparent southern part of the species’ range, and there could be other somewhat similar undocumented species in these areas. These females generally show a slight apical browning of the palpus which may be decurrent along its ventral margin, but the type specimens and the two additional males are apparently too old and faded to show this condition distinctly. In H. subacuta , with similarly coloured fore femur to H. australica , the palpus is consistently pale yellow to the apex and antenna 3 has relatively little infuscation. The small proepimeral bristle may be present or absent in H. australica .

Unfortunately the reared type specimens from Picton Lakes carry no information on larval habitat or habits.

Figures

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.