Cydistomyia bancroftae Mackerras, 1964

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 : 31-33

Cydistomyia bancroftae Mackerras

( Figs. 10 , 22 )

* Cydistomyia bancroftae Mackerras, 1964: 66 , figs 1–6; Daniels 1989; 286; Bickel & Elliot, 1998 -2005: 3. Holotype female and paratype male, S Qld, near Killarney (ANIC).

Other material examined. 56 ♀, 7 ♂.

Diagnosis. A medium-sized dimorphic species with dark chocolate brown and paler brown females, and light yellowish brown males. A highly characteristic Cydistomyia with relatively wide frons and parafacials, greatly reduced and indistinct linear callus, primitive short stubby antennae, and drab rather plain appearance of females. Length 12–14 mm.

Female (dark form).

Head. Eyes in life green, bare (short scattered hairs visible at 35X magnification). Frons medium, slightly divergent, index 3–4, dull brownish grey, with short black hairs; vertical triangle darker brown, ocellar spot small and irregular; callus dark brown, narrow, irregular, relatively inconspicuous, not extending beyond middle of frons. Subcallus, parafacials, and face dull brownish grey; subcallus pouting, with few dark hairs at sides; parafacials and face with short black hairs, mixed with some paler ones on lower part of parafacials; beard sparse, mixed black and dull brownish grey. Antennae of primitive form, short and stubby, with blunt or rounded dorsal angle; scape and pedicel dull fawn-brown, with short black hairs; flagellum brownish basally, darkening to blackish on distal part of basal plate and style, basal annuli of style sometimes compacted and difficult to distinguish. Palpi rather slender, bluntly pointed, dull fawn brown, with short black hairs.

Thorax. Scutum and scutellum mummy-brown, with traces of darker dorsocentral vittae, hairs almost uniformly black, except for some inconspicuous pale ones apically on scutum and marginally on scutellum. Pleura concolorous, with black hairs, except for some greyish white ones below and behind wing-root.

Legs. Brownish black, with black hairs, except for paler basal three-fourths or more of tibiae bearing admixture of dull cream hairs.

Wings. Greyish, costal cell brown; veins brown basally, blackish on apical two-thirds, vague blackish suffusion along R 2+3 and R 4+5, stigma dark brown, R 4 evenly curved, with slight thickening in position of appendix.

Abdomen. Deep almost blackish brown, with black hairs on discs of all tergites, narrow lighter brown cream-haired apical margins on tergites 2–5 or 6, pale hairs tending to extend irregularly forward in median zone of tergites 2–4. Venter similar, but pale hairs on apical margins of sternites fewer. Terminalia dorsoven- trally compressed; with distinctive pattern of pigment on distal part of 8 th sternite.

Pale female. Distinguished from dark form by following features: parafacials and palpi with entirely yellowish cream hairs; beard yellowish cream; antennal plate often more reddish; scutum and pleura with black hairs largely replaced by dull creamy yellow ones; legs paler, more like those of male; extensive scattering of dull yellowish cream hairs on abdominal tergites and sternites.

Male. Considerably paler than darker females. Eyes in life green, short scattered hairs visible at 15X magnification, not quite meeting in mid line, but showing narrow, deep frontal cleft, upper facets slightly enlarged and more or less clearly marked off from smaller, darker, lower and lateral ones, which do not extend above middle of eye at lateral margin. Ocellar tubercle elongate, only a little below level of eyes at vertex; group of creamy yellow hairs on postocular area, which is limited to narrow zone on either side of mid line. Frontal triangle, subcallus, parafacials, and face light yellowish fawn, parafacials bulging and with black or dull yellowish hairs, face somewhat sunken; beard creamy yellow. Antennae paler than in female; palpi about same colour as in female, but with more conspicuous black or yellowish hairs. Thorax brown with olive tint, and with relatively long, dense, dull yellowish cream to light brown hairs. Legs with brown femora, paler tibiae, darkening on distal tarsi, and with predominantly creamy yellow hairs giving place to black on the tarsi. Wings as in female, but basal and anterior veins light yellowish brown. Abdomen bright yellowish brown, darker olive brown on most of anterior half of 1 st tergite, with median, olive-brown patch on tergite 2, trace of median darkening on tergites 3–4, and more diffuse darkening on apical segments; hairs light golden. In some specimens the central darkening on tergites tends to form a vague median vitta. Venter similar to dorsum, but without median darkening, and with better-defined apical pale fringes on sternites 2–4. Terminalia undistinguished.

Distribution. From Cape York SE in QLD to NE NSW. QLD: Cape York, 1868, Thorey; Port Denison, 1868, Thorey; Eungella Nat. Pk. 85 km W Mackay, Feb., F.E. French; Rockhampton; Port Curtis; Bundaberg, Feb., H. Frauca; 9.5 km SE Biggenden, Dec., H. Frauca; Gympie, Apr., R. Eastwood; nr Killarney, Jan., J. Bancroft, I.M. Mackerras, M.J. Mackerras; Dagg's Falls, nr Killarney, Jan., J. Bancroft, I.M. Mackerras. NSW: Acacia Ck, nr Legume, Jan., M.J. Mackerras; Lismore, Richmond R., Dec., Kilgin, Richmond R., Dec.; Eltham, Feb., C.E. Chadwick; Piper’s Flat.

Figures

FIGURES 9–12. Antennal flagella: 9. Cydistomyia pseudoardens (Taylor), 10. Cydistomyia bancroftae Mackerras, 11. Cydistomyia improcerus Mackerras & Spratt, sp. nov., 12. Cydistomyia victoriensis (Ricardo).

FIGURES 22–24. 22. Cydistomyia bancroftae Mackerras frons, antenna, palp, female terminalia, sternite 8, spermathecal bulb. 23. Cydistomyia exemplum Mackerras & Spratt, sp. nov. frons, antenna, palp. 24. Cydistomyia obscurus Mackerras & Spratt, sp. nov. frons, antenna, palp.