Rhabdogaster pulverulentus ( Loew, 1858 )

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 : 279-280

Rhabdogaster pulverulentus ( Loew, 1858)

Figs 92–94 , 130

Spanurus pulverulentus Loew, 1858: 350 [1860: 164–165]; Hull 1962: 147; Oldroyd 1980: 369 (catalogue).

Type locality: South Africa (Stellenbosch).

Rhabdogaster pulverulentus: Londt 1993: 389–390 .

Description: Based on holotype ^(left antenna broken off beyond pedicel, right midleg missing, abdomen broken off at base and stuck to a card pinned below specimen) unless otherwise stated.

Head: Orange and dark red-brown, silver and gold pruinose, white and black setose. Antenna: Scape and pedicel orange-bown, postpedicel and style dark red-brown to black, setae black. Face yellow-brown, extensively pruinose except for two weakly pruinose spots in dorsal half. Mystax extensively white except for a few black setae dorsally, occupying most of face. Frons and vertex dark red-brown, extensively fine gold pruinose (except ocellar tubercle), black setose. Occiput dark red-brown except for small orange parts dorsolaterally, entirely pruinose. Proboscis red-brown, setae white, palpi with plp 1 orange with white setae, plp 2 orange with dark red-brown distal part, mostly black setose.

Thorax: Dark red-brown to black and orange, silver and gold pruinose, white and black setose. Mesonotum (somewhat worn as specimen is close to head of pin – details of pruinescence taken from Stellenbosch ơ) red-brown to black except for orange postpronotal and postalar lobes, pruinose except for pair anteromedial stripes (extend to transverse suture), 3 lateral spots (2 postsuture) and most of postpronotal and postalar lobes. Pleura gold and silver pruinose except for apruinose spots on an- and katepisternum. Scutellum dark red-brown and brown-orange, entirely silver pruinose, with 2 long black sctl s accompanied by approx. 4 black minor setae. Postmetacoxal bridge entirely gold pruinose. Legs: cx orange-brown and dark red-brown, silver and gold pruinose, mainly white (black on midcoxae) setose; troc orange and dark red-brown; fem orange, mid- and hind-legs with dark red-brown ventral surfaces, white setose except for some black macrosetae on ventral sides of legs 2 and 3; tib similar to fem, predominantly white setose (some black setae ventrodistally on legs 2 and 3); tar orange, mostly black setose (less so on leg 1). Wing 5.4 x 2.1 mm, veins yellow to brown, membrane transparent, slightly yellow-brown stained, entirely microtrichose (giving overall orange-brown appearance). Discal and costal cells entirely microtrichose.

Abdomen: Dark red-brown to black, gold and silver pruinose, mainly white setose. Tergites largely apruinose distomedially (T2–6), setae minute black on apruinose parts, white on pruinose parts. Sternites entirely strongly orange-gold and silver pruinose, moderately long pale yellow setose. Terminalia largely brown-orange. Male terminalia ( Figs 92–94 , Stellenbosch specimen): epand in lateral view shorter than external lobe of goncx but of similar length to hypd, tapering to rounded tips; in dorsal view lobes appear closely associated (but not fused) proximomedially; hypd in lateral view short,

fairly straight, slightly upcurved distally, projecting to about same level attained by epand; in ventral view broadly truncate proximally, tapering rapidly to short parallelsided terminal process with rounded apex. In lateral view external lobe of goncx fairly broad, tapering distally to fairly broadly-rounded tip. Internal lobe extending a little beyond level attained by external lobe. Gonst in ventral view slightly curved with long narrow terminal part.

Holotype: ^merely labelled ‘9’, ‘98’, ‘253’ ( NHRS).

Note: The specimen only carries a few numbered labels (see Londt 1993). Loew gives collection data as ‘Caffraria (Wahlb.)’. Wahlberg’s material from ‘Caffraria’ is usually assumed to originate from one of the many places visited during his extensive trip from Port Natal (now Durban) into the interior of the eastern parts of present day South Africa. Wahlberg did, however, spend a few months (February – May) in 1839, collecting in the vicinity of Cape Town ( Brinck 1955). Although Stellenbosch is not specifically mentioned in Brinck’s (1955) account of Wahlberg’s activities, it is possible that he visited that area. I here designate Stellenbosch as type locality.

Other material studied: SOUTH AFRICA: Western Cape: 1^‘ South Africa / Vredenburg [3254S:1959E] / 28-4-1927 / Ac . US.’; 1? ‘ South Africa / Somerset O. [Oos = East – 3243S:2535E] / Des. [Desember = December] 1944’; 2^1?, ‘ Cape Province / Ceres [3322S:1919E] / April 1925 ’, ‘ S. Africa / R.E. Turner. / Brit.Mus. / 1925-210’ ( BMNH); 1^‘ South Africa / Worcester [3339S:1926E] / 13.5.1942 ’; 1^‘ Franschhoek [3355S:1907E] / 20-4-46 / T. Malherbe’; 1^‘ South Africa / Stellenbosch [3356S:1851E] / 2.4.1942 / Ac . US. / A. C. Myburgh’; 1^‘ South Africa / Stellenbosch / 2 May. 1927 / Ac . US.’; 2^‘ South Africa / Stellenbosch / 12 May 1927 / Ac . US.’; 1^‘ South Africa / Stellenbosch / 20 April. 1936 / Ac. US.’; 1^‘ South Africa / Stellenbosch / 3-5-1927 / Ac . US.’; 1^‘ South Africa / Stellenbosch / 20 April. 1927 / Ac. US.’; 1^‘ South Africa / Stellenbosch / 29-9-1938 / Ac . US.’; 1ơ 1^‘ South Africa / G DG du Toit / April 1956 / Stellenbosch’; 1ơ ‘ South Africa / St-bosch [Stellenbosch] / 15-9-1940 ’; 1ơ ‘ South Africa / St-bosch / 27.2.1944 ’; 1^‘Suid-Africa / S.bosch / 10.4.1943 / E. C.Anderson’; 1^‘ South Africa / St bosch / 6.4.1957 / W.I. Wallierla [poorly written]’; 1^‘ Strand [3407S:1850E] / 20/4/40 / A. Myburgh’; 1^‘ So. Africa: SW. Cape, 7 km / S. Swellendam 3420 Ab / Bontebok National Pk. / March 1979 L. Braack / Malaise trap, nr. River’; Eastern Cape: 1^‘ Cape Province / Vanstadens / Pass [3354S:2512E], 100m / iv-20-58’, ‘ E.S. Ross & / R.E. Leech / collectors’ ( CASC) .

Most of the material is old and not well preserved.

Distribution, phenology and biology (Tables 1, 2, Fig. 130 ): Recorded only from South Africa. Known from a few localities in the Western Cape province of South Africa. Specimens have been collected mainly between February–May, but there are records for September and December.

Similar species: R. bicolor sp. n.

Figures

Figs 92–103. Rhabdogaster species, male terminalia: (92–94) R. pulverulentus (Loew, 1858), Stellenbosch: (92) lateral, (93) dorsal, (94) ventral; (95–97) R. quasinuda sp. n., Rawsonville holotype: (95) lateral, (96) dorsal, (97) ventral; (98–100) R. rustica Oldroyd, 1974, Garden Castle Nat. Res.: (98) lateral, (99) dorsal, (100) ventral; (101–103) R. sinis sp. n., Olifantshoek paratype: (101) lateral, (102) dorsal, (103) ventral. Scale bars = 1 mm.

Fig. 130. Distribution of Rhabdogaster species: pedion sp. n. – closed circles; pulverulentus (Loew, 1858) – open circles.