Afroholopogon xeros, Londt, 2005

Londt, Jason G. H., 2005, A review of afrotropical Afroholopogon Londt, 1994 with the description of a new genus and new species (Diptera: Asilidae: Stenopogoninae), African Invertebrates 46 (1937), pp. 203-252 : 227-228

Afroholopogon xeros sp. n.

Figs 58–60 , 78

Etymology: Gr. xeros (dry). Refers to the generally dry environments in which the species lives.

Description: Based on holotype.

Head: Antenna: Dark red-brown to black, fine silver pruinose, white setose; segmental formula 1.0:0.9:2.2:0.3:2.3. Face black, entirely silver pruinose, mystax white, strong, extending almost to antennal sockets. Face width:head width ratio 1.0:4.5. Frons and vertex black, shiny apruinose (a tiny patch of silver pruinescence lies in front of ocellar tubercle), long wavy white setose. Occiput black, silver pruinose except for bare area behind ocellar tubercle, white setose. Proboscis and palpi dark red-brown, white setose.

Thorax: Mesonotum black, apruinose except for narrow silver lateral and posterior margins, covered with long white setae. Setation: ac – long fine white (longer postsuture); dc – long fine white (longer postsuture); npl – 2 moderately long white; sa – 1 long slender white macroseta amongst many fine white setae; pa – approx. 2 fine white difficult to count amongst many fine long white setae. Scutellum black, shiny apruinose with narrow anterior silver pruinose margin, disc asetose, margin with approx. 26 thin white setae arranged in 2 rows. Pleura brown, fine silver pruinose except for bare areas on anepisternum, katepisternum and meron, white setose. Wing 4.8 x 1.9 mm, membrane transparent, veins yellow basally brown distally, microtrichia absent, basal angle of r 4 25°. Halter brown with yellow knob. Legs: cx black, silver pruinose, white setose; trochanters black; fem black, distal tips slightly paler dark red-brown, white setose; tib orange, distal tips dark red-brown, mainly white setose (some dark red-brown distally); tar dark red-brown, white and black setose.

Abdomen: Terga black, shiny apruinose except for small silver areas margins, long pale yellow setose. Sterna dark red-brown, pruinescence masked by many long pale yellow setae. Genitalia: ơ holotype not dissected and macerated, topotypic paratype ơ illustrated ( Figs 58–60 ): Hypopygium rotated through about 180°; epand (in dorsal view) deeply incised forming two basally connected distally projecting apically down-curved lobes that project beyond levels attained by goncx and hypd; goncx externally distally bilobed and not projecting (in lateral view) beyond levels attained by epand and hypd; hypd (in lateral view), robust, curved and of complex shape in ventral view ( Fig. 60 ).

Variation: Although some size variation is evident (wing-lengths from 3.7–6.5 mm) individual variation is minimal.

Type specimens: NAMIBIA: 1ơ paratype, Warmbad [1910S 1349E] / S.W.A. / Koakoveld’ ~ ‘ Mus. Exped. / Feb. 1925 ’ ( SAMC) ; 5ơ 7^ paratypes, ‘ Kamanyab [1938S 1450E] / S.W.A’ ~ ‘ Mus. Exped. / Mar. 1925 ’ ( SAMC) ; ơ holotype, 2ơ 8^ paratypes, ‘ Namibia 24.iii.1984 / 52 km W Outjo. Road 65 / 20 14'S: 15 40'E / Stuckenberg & Londt / Mopane woodland on a / rocky hillside.’; 4^ paratype, ‘ Namibia 20.iii.1984 / 60 km E Otjiwarongo. / Rd 101 20 39'S: 17 05'E / Londt & Stuckenberg / Acacia thornveld and / dry river course.’; 1ơ paratype, ‘SW Africa : / Tsisab Cyn. [2101S 1441E] / Brandberg Mts / v-11-58, 550 m’, ‘ E.S. Ross & / R. E. Leech / collectors’ ( CASC) ; 1ơ paratype, ‘ Namibia 27.iii.1984 / Omaruru commonage / 21 26'S: 15 57'E / Londt & Stuckenberg / Acacia savanna with / large boulders.’; 1ơ 4^ paratypes, ‘ Namibia 27.iii.1984 / 30 km S Omaruru. Road / 2/3 21 41'S: 15 57'E / Stuckenberg & Londt / Sparse Acacia scrub / in cattle pasture.’; 2ơ 3^ paratypes, ‘ Namibia 27.iii.1984 / Kahn River 24 km N of / Karibib. Road 2/3 / 21 47'S: 15 55'E / Londt & Stuckenberg / Acacias / Dry river bed.’; 2ơ 3^ paratypes, ‘ Namibia 27.iii.1984 / 10 km W Karibib. Road / 2/3 21 56'S: 15 45'E / Londt & Stuckenberg / Roadside shrubs with / open sandy patches.’; 1ơ paratype, ‘ Namibia 28.iii.1984 / 15 km W Usakos. Road 2/2 / 21 58'S: 15 30'E / Londt & Stuckenberg / Roadside vegetation – / flowers.’; 3^ paratypes, ‘ Namibia 28.iii.1984 / 43 km NW Usakos. Road / 1930 Spitzkop area. / 21 59'S: 15 21'E / Stuckenberg & Londt / Acacias, rocky area.’; 4ơ 2^ paratypes, ‘ Namibia 24.iv.1983 / 20 km W Usakos 2115CD / Londt & Stuckenberg / Sparse Savannah. ’; 3ơ 5^ paratypes, ‘ Namibia 24.iv.1983 / 10 km E Usakos 2115DC / Londt & Stuckenberg / Roadside vegetation.’ (1ơ 1^ BMNH) ; 1ơ paratype, ‘ Omaruru [2115S 1600E] / J.S. Brown / 1921’ ( SAMC) ; 1^ paratype, ‘ Namibia 28.iii.1984 / 20 km W Okahandja Road / 7/1. 21 56'S: 16 42'E / Stuckenberg & Londt / Mixed woodland with / bare ground.’; 1ơ paratype, ‘ Namibia 19.iii.1984 / 87 km SE Otjiworongo. / Rd. 57 21 03'S: 17 10'E / Stuckenberg & Londt / Acacia woodland with / long grass in seed.’; 1ơ paratype, ‘ Namibia 19.iii.1984 / Omuramba Omatako Riv. / Near Osire. Road 57 / 21 05'S: 17 15'E / Londt & Stuckenberg / Grassy road verges.’; 1ơ 1^ paratypes, ‘ Namibia 19.iii.1984 / 35 km W Otjosondu. Road / 57. 21 12'S: 17 31'E / Londt & Stuckenberg / Mixed Acacia woodland / with grassy patches.’; 1ơ paratype, ‘ Namibia 27.iii.1984 / Usakos. Town dump. / 22 00'S: 15 34'E / Stuckenberg & Londt / Poor Acacia woodland / stony ground.’; 1ơ paratype, ‘ Namibia 17.iii.1984 / 47 km W Witvlei. Road / 6/1. 22 22'S: 18 03'E / Stuckenberg & Londt / Acacia savanna with / shrubs and grass.’; 2^ paratypes, ‘ Namibia 17.iii.1984 / Witvlei, hill SW of / town. 22 26'S: 18 31'E / Stuckenberg & Londt / Acacias & low shrubs.’; 1^ paratype, ‘ Kalkfontein [2801S 1845E] / S.W.A. ’ ~ ‘ J.S. Brown / Oct. 1923 ’ ( SAMC) . SOUTH AFRICA: 1ơ paratype, ‘ Vioolsdrift [2846S 1739E] / Namaqualand’ ~ ‘ Museum Staff / March 1935 ’ ( SAMC) .

Distribution (Table 1), phenology (Table 2) and biology: Found over a fairly large area centred on Namibia ( Fig. 78 ). Much of the material was collected by me on two trips to the northern parts of the country. The species was commonly encountered at almost every locality visited and is almost certain to be encountered in the southern parts of the country which I have not visited at a suitable time. The species flies from February to May although a single record exists for October. Most of the material was swept from grass.

Similar species: Difficult to confuse with any other species, but considered most similar to chirundu and fugax and tanystylos (see discussion).

Figures

Figs 58–64. Afroholopogon and Ischiolobos species, genitalia:(58–60) A. xeros sp. n., male genitalia, paratype, 52 km W Outjo: (58) lateral, (59) dorsal, (60) ventral; (61, 62) A. capensis (Lindner, 1961), female genitalia, 9 km SW Willowmore: (61) lateral, (62) ventral; (63, 64) I. mesotopos sp. n., female genitalia, paratype, Queen Elizabeth Park: (63) lateral, (64) ventral. Scale lines = 0.5 mm.

Fig. 78. Southern African distribution of Afroholopogon Londt, 1994 species:aspros – closed circle, capensis – open circle, pardosoros – closed square, tanystylos – open square, uranopia – closed triangle, xeros – open triangle.