Cydistomyia musgravii (Taylor)

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 : 63-64

Cydistomyia musgravii (Taylor)

( Fig. 44 )

* Tabanus musgravii Taylor, 1918: 64 ; Ferguson 1920: 132. Holotype female, from Underbank, NSW (AM). Cydistomyia musgravii ; Mackerras, 1959: 168; Daniels, 1989: 287; Bickel & Elliot, 1998 -2005: 4.

Other material examined. 103 ♀, 9 ♂.

Diagnosis. A small to medium-sized, 10–12 mm, blackish species with narrow but well-defined pale apical bands and median spots on abdominal tergites, generally recognisable by presence of well-developed, shiny ocellar tubercle frequently with clearly visible ocelli; remarkable in having narrow oblique green band across eye of female, as occurs also in C. rivularis and C. atmophora . Distinguished from C. rivularis by plain grey abdominal venter without median broad dark vitta, and from C. atmophora by much general paler colouration and absence of dark shiny distinctly banded abdominal venter and predominantly pale 2 nd sternite. C. musgravii is distinguished from C. innubilus by banded eyes, darkish brown rather than greyish black abdominal colouration, particularly on the venter, wider frons with callus full width of frons at base, conspicuous ocellar tubercle, shorter fawn-brown rather than greyish black palps, brown legs, less conspicuous stigma and more rounded rather than sharply angulate vein R 4.

Cydistomyia musgravii is widely distributed, predominantly in mountain forest country.

Female. Head. Eyes in life reddish brown, with narrow bright green or blue-green oblique band at level of callus, bare (fine hairs visible at 35X magnification). Frons medium, parallel, index 3.0–3.8, with variegated grey and fawn tomentum, pale grey along eye margins, with scattered relatively long black hairs; vertex not hollow; vertical triangle greyish; ocellar tubercle raised, shiny, brown, oval or irregularly triangular, nearly always with well-defined anterior ocellus and frequently with other two ocelli developed as well; callus shiny, black, bulging, nearly full width of frons at base, pyriform, usually tapering evenly into extension which reaches one-half to two-thirds length of frons (not arising abruptly from rounded callus). Subcallus smooth, with ashy grey tomentum, yellowish above antennae, without hairs; parafacials and face with ashy grey tomentum and black hairs; beard greyish white. Antennal scape about as wide as long, pale greyish fawn, hairs black; pedicel cup-shaped, with short dorsal prolongation, slightly darker than scape, with black hairs; basal plate brown, with gentle ventral bulge anteriorly, moderately sharp dorsal angle posteriorly; style blackish brown. Palpi pale creamy fawn, with black hairs overall.

Thorax. Scutum dark brown with olive hue, rather wide greyish dorsocentral vittae and lateral margins, interrupted by brown stripe above wing root; paler colours not contrasting strongly with ground colour; hairs black and appressed yellowish cream, latter conspicuous only in front of scutellum. Scutellum dark olivebrown, greyish on margin; hairs as on scutum. Pleura pale grey, with relatively dense greyish white hairs, except for usual mixture of dark ones on upper mesopleural convexity.

Legs. Dark brown, femora with some greyish overlay, tarsi darkening to blackish brown; hairs greyish white on most of femora, black on anterior surface of fore femora, preponderantly black on tibiae, entirely black on tarsi.

Wings. Distinctly greyish, costal cell not darkened; stigma brown, fairly conspicuous; veins dark brown; sc with a few scattered setulae above, normal row below.

Abdomen. Brownish black with black hairs, basal tergites not as dark as apical ones; narrow well defined pale grey, creamy haired apical band on tergites 1–6, widening to form small but definite median triangle on 2nd tergite, widening slightly on others; extreme lateral margins pale, with black hairs basally and creamy white hairs at apical lateral corners on all tergites. Venter grey, contrasting with dark dorsum, sternites with narrow pale cream apical margins, hairs creamy white on apical edges and laterally.

Male. More brownish and more hairy than female. Eyes barely hairy (short fine hairs just visible at 15X magnification), meeting over most of length of frons, upper facets distinctly enlarged, brighter reddish brown than dark small lower and posterior ones, narrow band of yellowish brown facets separating the two areas. Ocellar tubercle small, distinct, sunken somewhat below level of eyes; ocelli not detected. Palpi subcylindrical, tapering, bluntly rounded apically, yellowish cream with mixed black and greyish white hairs.

Distribution. Mountain forest country from N QLD through ACT and NSW to Gippsland VIC. QLD: Ching Do, F.H. Taylor; Stanley R., Woodford, Mar., I.M. Mackerras; Point Lookout, Stradbroke Is., Oct., G. Daniels; Mt Mistake, nr Laidley, Jan., D.M. Spratt; Moggill, Feb., D.S. Kettle, biting; Binna Burra, biting, Dec., I.M. and M.J. Mackerras; Springbrook, Jan., H. Hacker; Bald Mt via Emu Vale, Jan., R. Coles; Mt Lamington, Dec., H. Womersley; Lamington Plateau, Jan.; Lamington Nat. Pk., H.J. Carter, Dec., H. Hacker, Feb., H.G. Greening; Bald Mt via Tannymorel, Dec., R. Eastwood; Numinbah Valley, Mar., I.M. and M.J. Mackerras; Queen Mary Falls Nat. Pk., Mar., J. Bancroft and I.M. Mackerras. ACT: Cotter R, nr Canberra, Jan., G. Schipp; NSW: Acacia Plateau via Legume, Jan., B. Cantrell; Boonoo SF, nr Tenterfield, Dec., 950m, Jan 1000 M\m, G. and A. Daniels; Ben Lomond, Mar., D.F. Waterhouse; Meldrum, Dec., Raven; Dorrigo, Jan.–Feb., T. Wright; scrub, nr Ebor, biting, Jan., I.M. and M.J. Mackerras; Point Lookout, nr Ebor, biting, Jan., I.M. and M.J. Mackerras; Barrington area, Gummi Plains, Mar., B. McMillan; Barrington Tops, Dec., G.M. Goldfinch, Jan.–Feb., S.U. Zool. Exp.; Eccleston, Mar.; Upper Allyn R., 457 m, Feb., I.F.B. Common and M.S. Upton; Blue Mtns, Mar.; Govett's Ck, Jan., B. McMillan; Mt Irvine, F.H. Taylor; Mt Victoria, Jan., M. Ekenberg; Blackheath, Feb., I.M. Mackerras; Jenolan Caves, 609 m, J.C. Wibord; Cordeaux, R., Feb., W.W. Froggatt; Colo Vale, Jan., W.W. Wirth, D.J. Lee, Feb., A.L. Dyce, B. McMillan, Mar., J. Citowitsch; 12 km SE of Crookwell, Jan., Carne, Helman and Greaves, Minnamurra Falls, Feb., C.E. Chadwick; Mt Coree, 914 m, 1219 m, A.C.T., Jan., I.F.B. Common; Bago Forest, Batlow, Mar., T.G. Campbell; Tinderry, bred from larva, Dec.; Snowy Plains, 1219 m, Feb. D.M. Spratt. VIC: Mansfield, Feb., G. Phillip; Mt Buangor, 427 m, 21 km NE of Beaufort, Feb., I.F.B. Common; Mt Disappointment, Feb., N. Dobrotworsky; Lyonville, Feb., N. Dobrotworsky; Lake Curlip, Gippsland, Feb., N. Dobrotworsky.

Remarks. One specimen is difficult to place. A small (9.5 mm) female from Kimberley Research Station, Ord R., WA, has a greyer abdomen with particularly pale 2 nd and 3 rd tergites, abdominal venter uniformly dark grey with narrow pale apical bands on each sternite, a narrower frons with shiny brown bulging and more oblong callus with short indistinct extension, broad basal plate without ventral bulge but with substantial dorsal angle, and dark fawn palps with a few mixed white and black hairs. This may represent a western form of C. musgravii .

Figures

FIGURES 43–45. 43. Cydistomyia victoriensis (Ricardo) frons, palp, antenna, female terminalia, sternite 8, spermathecal bulb. 44. Cydistomyia musgravii (Taylor) frons, palp, antenna, female terminalia, sternite 8, spermathecal bulb. 45. Cydistomyia rivularis (Ferguson & Hill) frons, palp, antenna, female terminalia, sternite 8, spermathecal bulb.