Cydistomyia pseudobrevior Mackerras & Spratt., 2008

Mackerras, I. M., Spratt, D. M. & Yeates, D. K., 2008, Revision of the horse fly genera Lissimas and Cydistomyia (Diptera: Tabanidae: Diachlorini) of Australia, Zootaxa 1886 (1), pp. 1-80 : 72-73

Cydistomyia pseudobrevior Mackerras & Spratt. sp. nov.

( Fig. 50 )

Type material. Holotype female, Qld , 5 km W by N of Rounded Hill, Oct. 1980, D.H. Colless ( ANIC) . Paratype females (5), same data as holotype ; 1 female, 1 km N of Rounded Hill , Oct. 1980, D.H. Colless ( ANIC) .

Non-type material examined. QLD: 19♀ 3 km NE of Mt Webb, Oct. , 1980, D.H. Colless ( ANIC) ; 1♀ Isabella Falls , Battle Camp Road via Cooktown, Dec., D.K. Yeates ( ANIC) .

Diagnosis. A small narrow-bodied yellowish-brown species, with pale apical bands on abdominal tergites and faint median triangles on tergites 2–4, raised bell-shaped callus, pedicel without dorsal prolongation, entire forelegs dark brown, yellowish costal and subcostal cells of wing and with well-defined right angle on vein R 4 but without appendix. To be distinguished from C. brevior by absence of ocellar tubercle and no suggestion of ocellar spots, tapering extension of callus generally not reaching to middle of frons, bulging subcallus, absence of a dorsal prolongation on the pedicel and presence of median triangles in midline on abdominal tergites 2–4.

Female. Head. Eyes in life green, bare (few scattered hairs barely visible at 35X magnification). Frons relatively narrow, parallel, index 4.0–4.2, with pale creamy fawn tomentum and short dark brown hairs; vertex hollow, vertical triangle ill defined, greyish brown with short black hairs; ocellar tubercle not observed; callus brown, shiny, distinctly raised, slightly narrower than frons at base, bell-shaped, with tapering extension generally not reaching to middle of frons. Subcallus bulging, smooth, with cream tomentum, without hairs; parafacials and face with greyish white tomentum and fawn white hairs; beard white. Antennal scape cylindrical, distinctly longer than wide, light yellowish cream, with short black hairs; Pedicel about half as long as wide, without dorsal prolongation, colour and hairs as on scape; basal plate brownish orange, with small dorsal angle projecting as small knob, with few short black hairs at angle; style brown. Palpi moderately plump, pale cream, with short black hairs.

Thorax. Scutum and scutellum almost uniformly brown, paler anteriorly and laterally, with short black and creamy white hairs. Pleura pale grey, with white hairs.

Legs. Femora brown, whole of foreleg dark brown with dark brown hairs, mid and hind femora with creamy to whitish hairs; tibiae brown, with dark brown hairs mixed with yellowish cream ones on paler parts; tarsi dark brown, with black hairs.

Wings. Pale greyish to almost clear, costal and subcostal cells yellowish; stigma yellowish brown; veins light yellowish brown, darker apically and distally; cell R 4 wide; vein R 4 angulate, without appendix.

Abdomen. First tergite yellowish fawn, tergites 2–4 light brown, remainder dark brown except 7 th, with light yellowish fawn apical bands; hairs dark on darker parts, yellowish cream on paler areas and forming median triangles in mid line on tergites 2–4. Venter brownish grey, with pale apical bands on sternites; hairs predominantly yellowish cream.

Remarks. A single male specimen from Iron Range, north Qld, Aug., R. Jenkins, collected on its own may represent the male of this species. It is small, narrow-bodied and distinguished from male C. brevior by darker abdomen and pale apical bands only on tergites 2–4, although present on all sternites; second segment of palpi short; antennal basal plate small but robust; legs pale.

Distribution. Cooktown region N QLD.

Etymology. The specific epithet derives from the similarity of the species to C. brevior which occurs in the Northern Territory while C. pseudobrevior appears restricted to north Queensland.

Figures

FIGURES 49–51. 49. Cydistomyia brevior (Walker) frons, antenna, palp, female terminalia, sternite 8, spermathecal bulb. 50. Cydistomyia pseudobrevior Mackerras & Spratt, sp. nov. frons, antenna, palp, female terminalia, sternite 8, spermathecal bulb. 51. Cydistomyia griseicolor (Ferguson & Hill) frons, antenna, palp, female terminalia, sternite 8, spermathecal bulb.