Afroholopogon futilis ( Wulp, 1899 ) Londt, 2010

Londt, Jason G. H., 2010, A review of Afrotropical Acnephalum Macquart, 1838, including the reinstatement of Sporadothrix Hermann, 1907 and descriptions of two new genera (Diptera: Asilidae: Stenopogoninae), African Invertebrates 51 (2), pp. 431-431 : 459-461

Afroholopogon futilis ( Wulp, 1899) comb. n.

Figs 2 , 52–54

Acnephalum futile: Wulp 1899: 87 (pl. II, fig. 11 wing venation); Kertesz 1909: 88 (catalogue); Engel 1929:

277; Hull 1962: 192; Oldroyd 1981: 359 (catalogue); Lehr 1988: 232 (catalogue).

On receipt of the type material it was immediately apparent that futilis should not have been described in Acnephalum as the specimens fail to display the diagnostic characteristics of the genus. Indeed, it is doubtful that any researcher has consulted the types since their original description. The species is fully congeneric with Afroholopogon and is therefore unhesitatingly transferred to that genus.

Redescription (Format follows that of Londt (2005). Based on lectotype ( Fig. 2 ). Condition: Excellent; right antenna broken off beyond pedicel.):

Head: Antenna: Dark red­brown, fine silver pruinose, white setose; segmental formula 1.0:1.1:3.3:0.3:1.3. Face black, entirely silver pruinose, mystax white, extending to antennal sockets, with vertical asetose strip medially. Face width:head width ratio 1.0:4.4. Frons and vertex black, frons apruinose except for silver lateral areas and a central spot. Vertex apruinose, fine white setose. Occiput dark red­brown to black, entirely silver pruinose, white setose. Proboscis and palpi dark red-brown, white setose.

Thorax: Mesonotum black, silver pruinose except for extensive apruinose spots and stripes, setae short, white (absent on some apruinose areas). Setation: ac – short white setulae; dc – short white; npl – 2 pale yellow-white; spal – absent; pal – 1 white. Scutellum black, entirely apruinose, disc asetose, margin with 7, white, medially directed, quite short apical macrosetae arranged in a single row. Pleura black, extensively silver pruinose, white setose. Wing 3.6× 1.5 mm, transparent, membrane entirely microtrichose, basal angle of cell r 4 19°. Haltere with pale yellow knob and light brown stalk. Legs: cx dark red-brown, silver pruinose, white setose; trochanters dark red-brown; fem red-brown with brown-orange distal end, pale yellow and white setose; tib orange-brown, pale yellowish setose (few black ventrodistally); tar orange-brown, pale yellowish (dorsally) and dark red-brown (ventrally) setose.

Abdomen: Terga dark red-brown, shiny apruinose except for silver areas posterolaterally (that extend medially to almost centre of tergum, but not along posterior margin), white setose. Sterna dark red-brown. silver pruinose, short white setose. Genitalia ( Figs 52– 54 ): Hypopygium unrotated; epand (in dorsal view) quite short (about as long as proc), shallowly incised to form short distolateral lobes; goncx externally distally bilobed and projecting (in lateral view) to a level beyond that reached by epand; hypd (laterally) of moderate length (longer than external lobe of goncx) and (ventrally) broadly rounded distally.

Variation: Paralectotype slightly smaller (wing 3.4 mm long), otherwise similar to lectotype.

Lectotype: ♂ SOUTH YEMEN: lectotype, ‘S. W. Arabia, / Aden. [12°46'N: 45°01'E] / Capt. Feb. 13.95 / & pres. 1899 by / J. W. Yerbury’ glued to ‘A. / capt. in / cop. with / B.’, ‘Type. / v.d.Wulp, Trans. Ent. Soc., / 1899, page 87, / pl. ii, fig.11.’, ‘ Acnephalum / futile n. s.’, ‘1899 / 7704’, ‘4’, ‘Type Dip: 154 1/2 / Acnephalum / futile / v.d. Wulp / Hope Dept. Oxford’ (OXUM).

Paralectotype: ♀ SOUTH YEMEN: ‘S. W. Arabia, / Aden. / Capt. Feb. 13.95 / & pres. 1899 by / J. W. Yerbury’ glued to ‘B. / capt. in / cop. with / A.’, ‘Type. / v.d.Wulp, Trans. Ent. Soc., / 1899, page 87, / pl. ii, fig. 11.’, ‘ Acnephalum / futile n. s.’, ‘1899 / 7703’, ‘Type Dip: 154 2/2 / Acnephalum / futile / v.d. Wulp / Hope Dept. Oxford’ (OXUM).

Lectotype designation:Wulp described the species on ‘a pair in coitu, from Aden’.As he did not designate a holotype, the specimens are considered syntypes.For reasons of taxonomic stability I hereby designate the male as lectotype and the female as paralectotype. Distribution, phenology and biology: The species is only known from the type locality. Specimens were collected in February. Nothing is known of its biology.

Similar species: Wulp (1899) stated that futile was ‘closely allied to Dasypogon (Acnephalum) andrenoides ’, a comment echoed by Engel (1929). The similarity is, however, minimal and it is surprising that Engel did not suspect a misallocation.

Afroholopogon was fully revised by Londt (2005), who gave an historical account together with redescriptions and descriptions of 17 species, most of which are southern African. Using Londt’s key to species reveals that futilis keys out at the end of the key together with three other species – dasys Londt , 2005, pardosoros Londt , 2005 and uranopia Londt , 2005. Two of these are known only from South Africa (pardosoros from the Tierberg Nature Reserve , and uranopia from the Graaff-Reinet area) while dasys is known from three specimens from Eritrea, Oman, and the Yemenese island of Abd al Kuri. Besides the characters provided in the key below there are obvious differences to be observed in male genital form .

A. futilis can easily be incorporated into Londt’s (2005) key by making the following small modifications to the final couplets:

15 Mesonotal pruinescence entirely gold; apical scutellar setal number>40 .............. .................................................................................................... dasys Londt, 2005 – Mesonotal pruinescence silver (uranopia female has silver laterally and gold medially); apical scutellar setal number <30............................................................16 16 Eye anteromedially flattened, especially in male; male with facial area occupied by mystax shiny apruinose; scutellum with c. 20 apical macrosetae....................... .............................................................................................. uranopia Londt, 2005

– Eye not anteromedially flattened; male with facial area occupied by mystax entirely silver pruinose ......................................................................................................17

17 Face broarder in relation to head (1:<5); supra-alar macrosetae absent; scutellum with <10 apical macrosetae; wing with basal angle of r 4 <20°; known only from South Yemen............................................................................ futilis ( Wulp, 1899)

– Face narrower in relation to head (1:>5); 1 supra-alar macroseta present; scutellum with>20 apical macrosetae; wing with basal angle of r 4>25°; known only from South Africa..................................................................... pardosoros Londt, 2005

Figures

Figs 1–5. Appearance of entire specimens: (1) Acnephalomyia andrenoides (Wiedemann, 1828) [lectotype ♂ Dasypogon quadratus Wiedemann, 1828]; (2) Afroholopogon futilis (Wulp, 1899) [lectotype ♂ Acnephalum futilis Wulp, 1899]; (3) Sporadothrix gracilis Hermann, 1907, ♂ from 65 km SE Noenieput; (4) Ammodaimon platythrix sp. n., holotype ♂; (5) Astiptomyia bikos sp. n., paratype ♀.

Figs 52–63. Male terminalia: (52–54) Afroholopogon futilis (Wulp, 1899) lectotype, lateral, dorsal and ventral; (55–57) Sporadothrix gracilis Hermann, 1907, holotype, lateral, dorsal and ventral; (58–60) Ammodaimon platythrix sp. n. holotype,lateral, dorsal and ventral; (61–63) Astiptomyia bikos sp. n. holotype lateral, dorsal and ventral. Scale lines = 1 mm.