Rhabdogaster oldroydi ( Lindner, 1973 ) Londt, 2006

Londt, Jason G. H., 2006, A review of the Afrotropical genus Rhabdogaster Loew, 1858 with descriptions of new species (Diptera: Asilidae: Stenopogoninae), African Invertebrates 47, pp. 243-313 : 271-272

Rhabdogaster oldroydi ( Lindner, 1973) , comb. n.

Figs 74–76 , 129

Heteropogon oldroydi Lindner, 1973: 78 ; Oldroyd 1974: 44 (footnote mention only); 1980: 362 (catalogue).

Type locality: Namibia (Daan Viljoen Nature Reserve).

Afroholopogon oldroydi: Londt 1994 a: 64 .

Redescription: Based on holotype ^.

Head: Black, silver pruinose, white setose.Antenna black, setae white. Face extensively pruinose, except for central shiny apruinose area. Mystax entirely white, occupying approx. lower half of face. Frons partly pruinose, vertex entirely apruinose (including ocellar tubercle). Occiput entirely pruinose. Proboscis and palpi dark red-brown to black, setae white.

Thorax: Dark red-brown to black, silver pruinose, white setose. Mesonotum extensively apruinose including central areas, postpronotal and postalar lobes. Pleura entensively pruinose with apruinose spots on an- and katepisternum. Scutellum extensively pruinose except for hind margin and small central area, with approx. 8 moderately developed white sctl s accompanied by approx. 10 tiny setae. Postmetacoxal bridge entirely goldsilver pruinose. Legs: cx dark red-brown, silver pruinose, white setose; troc orange and red-brown; fem dark red-brown with orange distal and proximal ends, white setose; tib orange, predominantly white setose (a few black setae ventrodistally); tar brown-orange, mostly black setose. Wing 7.9 x 2.9 mm, veins orange anteriorly, brown posteriorly, membrane transparent, weakly yellow stained, extensively dark microtrichose. Discal cell microtrichose, costal cell with a few microtrichia distally.

Abdomen: Black, silver pruinose, white setose. Tergites apruinose except for lateral margins. Sternites entirely pruinose.

Variation: Other females agree well with the holotype. The species does however display significant sexual dimorphism. Apart from being smaller, the Ai Ais ơ differs from the holotype in the following important ways.

Head: Antennal setae black. Face entirely pruinose and without central shiny apruinose area. Mystax occupying approx. lower one-third of face.

Thorax: Pleura more extensively apruinose.Scutellum entirely apruinose except for anterior margin, sctl s dark red-brown. Postmetacoxal bridge entirely apruinose. Legs: fem entirely orange, many black setae are present (including some stout ones ventrally); tib have many black setae; tar dark red-brown. Wing 4.6 x 1.9 mm, veins mostly brown, membrane transparent, more strongly yellow stained. Costal cell with more microtrichia distally.

Abdomen: Sternites largely apruinose. Terminalia ( Figs 74–76 , Fish River Canyon specimen): epand in lateral view much longer than external lobes of goncx and similar in length to hypd, tapering to rounded tips; in dorsal view lobes narrowly separated proximomedially; hypd in lateral view more or less straight, longer than external lobe of goncx; in ventral view broadly-rounded proximally, tapering rapidly to moderately long, process with enlarged mid-section and rounded apex. In lateral view external and internal lobes of goncx clearly fused hardly visible.

Holotype: ^NAMIBIA: ‘Daan Viljoen [Nature Reserve – 2232S:1658E] SWA. / 19. – 21.1.1970 / Lindner leg.’, ‘ Heteropogon / Sp. 1 / det. H. Oldroyd 1970 ’, ‘ Heteropogon / oldroydi / Lindner det. Lind.’, ‘Typus / Lindner / 1973’ [white, red ink, black border – date sideways] (SMNS).

Other material studied: NAMIBIA: 1^‘ Kaoko Otavi [1818S:1342E] / S.W.A.’ ~ ‘ Mus. Expd. / Mar. 1926 ’ ( SAMC) ; 1ơ ‘ Kawares [1903S:1421E] / S.W.A.’ ~ ‘ Mus. Expd. / Mar. 1926 ’ ( SAMC) ; 2^‘ Kaross [1930S:1420E] / S.W.A.’ ~ ‘ Mus. Exped. / Feb. 1925 ’ ( SAMC) ; 1^‘ South West Africa 2217 Ca / Windhoek Dist. Auasberge / 21 km. S. Windhoek, 1800m. / 31-I-1974, ME Irwin / sandy wash in mountains’; 1^‘ South West Africa 2415 Bb / Maltahöhe Dist. 25 km. S / Salitaire on Dieprivier / Farm, 15-II-1974, 1000m. / ME Irwin, gravel wash’; 1ơ ‘ Gorrasis 99 / Lüderitz / SE2515 Bd / 12–15 Feb. 1973 ’, ‘H11584’ ( NMNW) ; 1ơ ‘ Namibia , Fish River Canyon / Park, 13 km. E. Ai Ais, 330m. / malaise in dry wash in / canyon draw; 19-xi- 1996; M.E. / Irwin, EI Schlinger, DK Yeates / 27 ° 55'22"S. 17 ° 31'04"E’ .

Distribution, phenology and biology (Tables 1, 2, Fig. 129 ): Recorded only from Namibia. Specimens are from seven localities, and collected in November, January, February and March, indicating that the species flies during summer in that summer rainfall region.

Similar species: R. karoo sp. n. and tanylabis sp. n.

Figures

Figs 68–79. Rhabdogaster species, male terminalia: (68–70) R. nuda Loew, 1858, Stellenbosch: (68) lateral, (69) dorsal, (70) ventral; (71–73) R. nyx sp. n., Gt. Winterhoek holotype: (71) lateral, (72) dorsal, (73) ventral; (74–76) R.oldroydi (Lindner, 1973), Fish River: (74) lateral, (75) dorsal, (76) ventral; (77–79) R. oresbios sp. n., Cathedral Peak paratype: (77) lateral, (78) dorsal, (79) ventral. Scale bars = 1 mm.

Fig. 129. Distribution of Rhabdogaster species: oldroydi (Lindner, 1973) – closed circles; oresbios sp. n. – open circles; pellos sp. n. – closed squares; poa sp. n. – open squares.