Helosciomyza neboissi, 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 : 63-64

Helosciomyza neboissi n.sp.

Fig. 21

Type material. Holotype ♂. Tasmania: Pelion [probably Pelion Hut vicinity, c. 41°50'S 146°03'E, c. 870 m —E.D.E. pers. comm.], 9.i.1991, I.D.N., E.D.E. ( ANIC). Impaled on long pin after preservation in ethanol; genitalia extended and exposed . Paratypes. Tasmania: 1♂, 1♀, same data as holotype ( AM, ANIC) ; 1♂, 1♀, Bluff Hill, 12 km S of Marrakesh, near Arthur River , Nov. 1974, A.N. ( MV) .

Description (male, female). Resembling H. bickeli and especially H. subacuta ; agreeing with description of former species, except as indicated below.

Coloration (all specimens with pruinescence of head and thorax somewhat discoloured through initial immersion in liquid or retention in a humidified container, but cuticular pigment apparently unfaded). Upper occiput apparently without tawny spot between each outer vertical bristle and eye margin. Antennal segment 3 tawny, with only slightly darker tawny dorsal zone. Mesoscutum without dark cuticular stripes underlying pruinescent longitudinal stripes. Fore femur pale orange-tawny, with dark brown subapical spot on posterior surface narrowly connected dorsally to larger subapical brown mark on anterior surface, but usually without brown zones on basal three-quarters of length; other femora with dark brown apical to subapical zones; tibiae with brown apical zones, hind tibia with additional sub-basal brown zone; segment 3 of fore tarsus largely brown. Wing with slight brown markings as in H. bickeli etc.

Head. Cheek 0.34–0.35 as high as eye.

Thorax. Pteropleuron and hypopleuron without setulae; proepimeral bristle minute or absent. Legs and wing much as in H. bickeli .

Abdomen. Sternite 1 almost completely desclerotized, without setulae. Male postabdomen: surstylus approximately transverse at basal articulation, shaped somewhat like that of H. subacuta but broader, more broadly truncate apically, with rather large posterobasal setulose tubercle (inconspicuous from some angles), numerous but not dense long setulae or mollisetae near middle of outer surface, and posterior sub-basal patch of microtrichia ( Fig. 21 ). Female: postabdominal sclerites apparently as described for H. bickeli .

Dimensions. Total length, ♂ 5.7–7.7 mm, ♀ 7.0– 7.7 mm; length of thorax, ♂ 2.6–3.7 mm, ♀ 3.3–3.4 mm; length of wing, ♂ 6.3–7.7 mm, ♀ 7.4 mm.

Distribution. Tasmania: north-western districts, including elevations of c. 870 m or more.

Notes

Helosciomyza neboissi is most similar to H. subacuta , which it resembles in the absence of setulae on sternite 1, in coloration of the antenna, and in the usual absence of any brown zone on the anterior surface of the fore femur other than the subapical zone (but one specimen shows some brown suffusion on the more basal part of the anterior surface of both fore femora). It differs from H. subacuta in the characters indicated in the key and, in the male, in the broader surstylus with setulose basal tubercle. Also, the two species are perhaps geographically isolated as indicated by presently available data.

The specific epithet refers to Arturs Neboiss, formerly of the Museum of Victoria, who first collected the species, and is remembered for his helpfulness and hospitality.

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.