Cydistomyia innubilus 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 : 69

Cydistomyia innubilus Mackerras & Spratt , sp. nov.

( Fig. 48 )

Type material. Holotype female, NT, Koongarra , 15 km E of Mt Cahill, Mar. 1973, D.H. Colless ( ANIC) . Paratype male, same data as for holotype except Nov. 1972 ( ANIC) .

Non-type material examined. NT: 1♀ Holmes Jungle, 14 km NE of Darwin, Mar. , 1965, Gressitt ( ANIC) ; 1♀ 22 km WSW of Borroloola, Malaise trap, Apr., 1976, D.H. Colless ( ANIC) .

Diagnosis. A medium-sized greyish black species closely resembling Dasybasis griseoannulata (Taylor) but distinguished from it by wider frons, callus markedly narrower than frons at base and with broader extension, absence of appendix on R 4 and absence of brown suffusion on wings. Length 10–12 mm.

Female. Head. Eyes (relaxed) green with red brown reflections, wide, bare (short hairs just visible at 35X magnification). Frons long, moderately narrow, slightly divergent, index 3.7–4.1, with fawn tomentum, pale grey at sides, with short inconspicuous dark hairs over middle; vertex flat; vertical triangle grey, moderately well-defined, with short dark hairs; ocellar tubercle well defined, flat, anterior ocellar-spot clear, posterior ocelli not observed; callus dark brown, conspicuously narrower than frons at base, elongate, pyriform, tapering into moderately narrow extension which reaches one-half to two-thirds length of frons. Subcallus with pale creamy tomentum, with fawn tint above antennae, without hairs; parafacials and face pale grey, with short white hairs; beard white. Antennal scape dark brown with some greyish overlay, hairs black; pedicel with dorsal prolongation, dark brown, with short dark hairs distally; basal plate wide, orange-brown, with sharp dorsal angle bearing few short dark hairs; style darker orange-brown. Palpi grey-brown, with white hairs basally, short black ones on distal two-thirds.

Thorax. Scutum greyish brown, almost uniform over disc, somewhat paler on side margins; scutellum darker, hairs inconspicuous black and dull creamy white. Pleura pale grey, with creamy white hairs.

Legs. Dark, almost blackish brown, with dark brown hairs on all segments.

Wings. Clear to very pale greyish, without brown suffusion, costal cell not darker than others; stigma dark brown; veins brown.

Abdomen. First tergite greyish black, with barely discernible narrow greyish white apical margin, remainder blackish brown with black hairs, with narrow pale grey apical margins covered with creamy white hairs, appearing banded. Venter similar, with narrow pale grey apical margins covered with creamy white hairs.

Male. Similar to female but with narrower pale apical bands on abdominal tergites and particularly on sternites. Eyes large, bare (scattered short hairs visible at 35X magnification), upper facets greatly enlarged, brighter reddish brown (not fawnish) contrasting with darker lower facets and narrow posterior margin. Antennae more slender than in female but with strong dorsal angle bearing few short black hairs. Palpi fusiform, tapering abruptly to point, cream coloured (not brown), with long white hairs and a few brown ones laterally and distally.

Distribution. From Darwin to Borroloola NT.

Etymology. The specific epithet drives from the Latin for cloudless and refers to the clear unclouded wings of this species.

Figures

FIGURES 46–48. 46. Cydistomyia atmophora (Taylor) frons, palp, antenna, female terminalia, sternite 8. 47. Cydistomyia silviformis (Taylor) frons, palp, antenna. 48. Cydistomyia innubilus Mackerras & Spratt, sp. nov. frons, palp, antenna, female terminalia, sternite 8, spermathecal bulb.