Cydistomyia laticallosa (Ricardo)

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 : 48-49

Cydistomyia laticallosa (Ricardo)

( Fig. 35 )

* Tabanus laticallosus Ricardo, 1914: 395 ; Froggatt 1915: 17 (misspelled luticallosus); Taylor 1917b: 524; Surcouf 1921: 73; Ferguson & Hill 1922: 252; Hardy 1944: 84; Chainey, 1990; Holotype female, paratype female, from Moreton Island, south Qld (BMNH).

Cydistomyia laticallosa: Mackerras 1959: 167 ; Daniels, 1989: 287; Bickel & Elliot, 1998 -2005: 4.

* Tabanus rufoabdominalis Taylor, 1917b: 525 ; Ferguson: 1920: 132; Ferguson & Hill 1922: 252 (syn. of laticallosus Ric. ); Mackerras 1959: 167 (confirmed synonymy). Syntypes, male and female, from Stradbroke Island, south Qld (QM).

* Tabanus heroni Ferguson, 1921 a: 372 ; Ferguson & Hill 1922: 252 (large var. of laticallosus Ric. ); Hardy 1939: 42 (var. of victoriensis Ric. , in Ferguson), 1944: 84. Holotype female, from Dorrigo, NSW (SAM).\

Cydistomyia laticallosa var. heroni ; Mackerras 1959: 167.

Other material examined. 24 ♀, 8 ♂.

Diagnosis. A medium to large-sized brown species with some variable brown suffusion on the wings. To be distinguished from C. improcerus and C. duplonotata by less conspicuous abdominal pattern — the interrupted or sometimes complete narrow dark median vitta bearing almost no indication of an internal pale vitta or median pale apical triangles on the tergites, elongate grey-black basal plate with acute dorsal angle, robust dark grey palpi, generally narrower frons, and often more bulging broader callus. Length 14–19 mm.

Female. Head. Eyes green in life, bare (fine hairs just visible at 35X magnification). Frons narrow, parallel, index 4.7–5.9, covered with rather dark fawn-brown or greyish cream tomentum and short dark hairs; vertex flat; vertical triangle ill-defined, ocellar tubercle prominent and partly shiny, indications of three ocellar spots, anterior spot best defined; callus oblong, about three-fourths width of frons at base, with irregularly tapered extension to upper third of frons, portion just above main callus somewhat hollow and irregular. Subcallus with dull fawn to creamy tomentum, without hairs; parafacials with dull greyish fawn to greyish cream tomentum, short black hairs, some longer golden ones on lower part; face more greyish, with some black hairs above and a few golden ones below; beard yellow to dull creamy. Antennae relatively slender, uniformly greyish black, with short black hairs throughout, basal portion of flagellum elongate with acute dorsal angle forming short but sharp upwardly pointing tooth. Palpi dull greyish fawn, with short dark hairs.

Thorax. Scutum and scutellum dark brown with faint olive hue, greyish anteriorly and on side margins, with irregular black and rather sparse yellow hairs. Supra and postalar tufts and marginal hairs on scutellum yellow. Pleura grey to light fawn, with yellow to deep orange-yellow hairs.

Legs. Black; hairs black, except for some admixture of orange-yellow ones on femora.

Wings. Light greyish, with faint brownish hue; costal cell brown, variable and irregular light brownish suffusion in radial area beyond first basal cell; stigma dark brown.

Abdomen. Reddish brown, with vague blackening in median area of tergites and more extensively on fifth and subsequent tergites; hairs black, except for yellow apical fringe, small median apical yellow to cream triangles and yellow lateral margins on tergites 2–5. Venter bright brown basally, darker on apical sternites, with pale yellow-haired apical margins to all sternites, hairs mixed yellow and black elsewhere.

Male. Similar to female but dark median markings on second abdominal tergite more prominent. Eyes bare (few scattered hairs just visible at 35X magnification), green, meeting in mid line, upper facets not enlarged. Ocellar tubercle prominent, raised above level of eyes, ocelli not observed. Palpi grey to light fawn, gently tapering to rounded point, with long black and creamy yellow hairs. Legs more brownish than in female, hind tibial fringe stronger.

Distribution. Coastal SE QLD to NE NSW. QLD: Kroombit Tops, 45 km SSW of Calliope, Dec., G. Monteith and G. Thompson; Point Vernon, via Maryborough, Dec., H.A. Standfast; Noosa, Oct.; Woombye, Dec., D.H. Colless; Deep Water Nat. Pk., 65 km NW of Bundaberg, Sept., G.B. and S.R. Monteith; Brisbane, F.H. Taylor; Dunwich, Oct., Stradbroke Is., Sept., H. Hacker, J.B. Cleland, Oct., H. Hacker, I.M. and M.J. Mackerras. NSW: Byron Bay, Nov., Marr; Bangalow, Nov., Marr; Ballina, Jan.; Meldrum, Dec., Raven; Surveyor’s Ck, Gibraltar Ra. Nat. Pk., Jan., J. and A. Skevington.

Remarks. Two forms were previously recognised: the laticallosa (Ricardo) form and the generally larger and more broadly built heroni (Ferguson) form. There is considerable variation in size and in the degree of suffusion along wing veins, and distributions overlap.

One specimen in QM is difficult to place. A female from Fraser Is., Qld., Nov., H. Burton has the same very slender antennae and plump palpi but has a reddish brown abdomen without a dark median vitta, with black mottling on the fourth and subsequent tergites, without yellow apical fringes and small median apical yellow triangles on the tergites but with yellow lateral margins on tergites 1–6. The specimen has an indistinct ocellar tubercle, more white than yellow beard, antennae with a slight ventral bulge opposite the sharp upward pointing tooth on the orange brown basal plate contrasting with greyish black style, greyish black scutum and scutellum more brown on side margins, with brown rather than black legs and with faint brownish wings with no suggestion of brown suffusion in the radial area beyond the first basal cell or along wing veins.

Figures

FIGURES 34–36. 34. Cydistomyia improcerus Mackerras & Spratt, sp. nov. frons, palp, antenna, female terminalia, sternite 8, spermathecal bulb. 35. Cydistomyia laticallosa (Ricardo) frons, palp, antenna, female terminalia, sternite 8, spermathecal bulb. 36. Cydistomyia doddi (Taylor) frons, palp, antenna, female terminalia, sternite 8, spermathecal bulb.