Afroholopogon aspros, 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 : 211-213

Afroholopogon aspros sp. n.

Figs 16–19 , 78

Etymology: Gr. aspros (white). Refers to the long white setae that cover much of the head, thorax and abdomen of this species.

Description: Based on holotype.

Head: Antenna: Black (tip of style slightly orange), fine silver pruinose (especially scape), white setose; segmental formula 1.0:1.0:3.0:0.5:1.9. Face black, entirely silver pruinose, mystax white (strong setae along epistomal margin, slightly weaker dorsally and extending over entire face). Face width:head width ratio 1.0:4.4. Frons and vertex black, mostly shiny apruinose (little silver pruinose), dark brown setose, ocellar setae brown and white. Occiput black, silver pruinose (except posterior to ocellar tubercle), white setose. Proboscis dark red-brown to black, white setose. Palpi black, white setose.

Thorax: Mesonotum black, shiny apruinose except for narrow silver pruinose lateral and posterior margins. Setation: ac – long fine white; dc – long fine white; npl – 2 poorly developed white; sa – long fine white (may be a few weak macrosetae); pa – long weak fine white. Scutellum black, largely shiny apruinose except for narrow silver pruinose anterior margin, disc asetose, margin with approx. 16 thin white setae. Pleura black, silver pruinose except for apruinose spot on anepisternum and katepisternum, white setose. Wing 4.9 x 1.7 mm, membrane transparent (slight milky appearance), microtrichia weak to absent, basal angle of r 4 20°. Halter brown-yellow with pale brownyellow knob. Legs: cx black, silver pruinose, white setose; trochanters black; fem black with orange distal end, fine white setose; tib orange with dark red-brown to black distal end (more extensive on tib 3), white setose; tar black, white setose.

Abdomen: Terga black, shiny apruinose except for gold-silver lateral margins, fine white setose (short medially, long laterally). Sterna black, entirely silver pruinose, long fine white setose. Genitalia: Paratype illustrated ( Figs 16–18 ): Hypopygium unrotated; epand (in dorsal view) deeply incised medially to form two acutely pointed lobes hardly joined basally; goncx externally distally unilobed, lobes of distinctive shape; hypd (in lateral view) of moderate length, not projecting distally beyond level attained by goncx, suddenly tapering (in ventral view) to a single medial laterally flanged process.

Variation: Sexes similar. Some variation in size appears noteworthy (e.g. four females collected on 19 April at Umgeni Valley display a wing-length range of 4.6–5.8 mm). A little variation in hypandrial shape occurs (see Fig. 19 ).

Type specimens: SOUTH AFRICA: 1ơ 1^ paratypes, ‘near Lilani [2907S 3051E] / Ahrens district / Natal, S. Africa / B. & P. Stuckenberg / April 1962 ’, ‘ Holopogon / fugax Loew / det. H. Oldroyd 1973’; 1^ paratype, ‘Sth Africa: KZ-Natal / Umgeni Valley Nat. Res. / Dwarf’s Dawdle 870 m / 29°28'36''S 30°15'39" / 6.iv.1994 JGH Londt / Grassland & forest edge’; 4^ paratypes, ‘STH AFRICA: KZ-Natal / Umgeni Valley Nat. Res. / 29°28'43''S 30°15'39''E / 19 iv. 2005 JGH Londt / 969 m Black Eagle Trail / Swept Aristida grassland’; ơ holotype, 4ơ 25^ paratypes, ‘STH AFRICA: KZ-Natal / Umgeni Valley Nat. Res. / 29°28'43''S 30°15'39''E / 28 iv. 2005 JGH Londt / 969 m Black Eagle Trail / Swept Aristida grassland’ (1ơ 1^ BMNH); 1^ paratype, ‘S. Africa: Natal #5 / 15 km NE of Howick / 2930Ac 1500 m / 5.v.1984 R. Miller / Karkloof Falls’; 1^ paratype, ‘South Africa: Natal / Nkandla Forest / 3108E 2843S 25.v.86 / P E Reavell 1200 m / Ngongoni veld’.

Distribution (Table 1), phenology (Table 2) and biology: Known from a few localities in KwaZulu-Natal ( Fig. 78 ). The species flies during April and May. Little biological information is available except that the species inhabits Aristida dominated grassland. Females may greatly outnumber males in collections. A series of 6ơ and 29^, that included the holotype and 1ơ 4^ preserved in alcohol for future molecular studies (not considered paratypes and therefore excluded from the material listed above), constitutes material collected during an intensive two-hour sampling period. Males represented only 17% of the sample. Further collections are required to explain this apparent imbalance.

Similar species: Superficially similar to fugax but most similar to anassa and argos (see discussion).

Figures

Figs 7–19. Afroholopogon species, male genitalia: (7–9) A. africanus (Ricardo, 1925), Op Die Berg: (7) lateral, (8) dorsal, (9) ventral; (10–12) A. anassa sp. n., paratype, Pelgrimsrus: (10) lateral, (11) dorsal, (12) ventral, hypandrium only; (13–15) A. argos sp. n., paratype, 9 km NE Kranskop: (13) lateral, (14) dorsal, (15) ventral view of hypandrium; (16–19) A. aspros sp. n.; (16–18) paratype, Lilani: (16) lateral, (17) dorsal, (18) ventral, (19) paratype, Umgeni Nature Reserve, ventral view of distal end of hypandrium. 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.