Afromelittodes solis Oldroyd & Van Bruggen, 1963

Londt, Jason G. H., 2003, A revision of the afrotropical genus Afromelittodes Oldroyd & Van Bruggen, 1963 (Diptera: Asilidae: Laphriinae) and discussion of its possible mimetic resemblance to bees of the genus Megachile, African Invertebrates 44 (2), pp. 133-146 : 135-137

Afromelittodes solis Oldroyd & Van Bruggen, 1963

(Plate 1 A, Figs 6–7 , 8–16 , 30 )

Afromelittodes solis Oldroyd & Van Bruggen, 1963: 191

Redescription: Based on the unique holotype which is in excellent condition except that the entire left hind tarsus is gummed to the type label and the last 3 tarsomeres of the right tarsus are gummed to the locality label.

Head: Antenna dark red-brown to black, junctions between first three elements orangebrown; sockets narrowly separated by sclerotised strip no wider than width of two large mystacal macrosetae; scape somewhat swollen (about 1.5 times as long as broad), medial surface flat and asetose, setae mixed black and white (predominantly black ventrally and white dorsally, black setae much better developed than white ones); pedicel about twice as long as maximum breadth, setae mixed black and white (black setae better developed and encircle segment distally); postpedicel about three times as long as broad (in lateral view), asetose, red-gold pruinose except for proximal quarter which is silver pruinose; stylus comprises two elements, a short cylindrical basal element, slightly broader than long, and a distal spine-like element approximately the same length as basal element. Face moderately gibbous in lower half, entirely covered with black and pale yellowish setae, those situated on gibbosity all of similar size; setae bordering eyes yellowish and lying almost parallel to facial surface. Vertex deeply sunken such that cone-like ocellar tubercle lies well below an imaginary line drawn between upper surfaces of eyes. Frons and anterior parts of vertex with many black setae (a few white ones adjacent to eye margins). Occipital area and posterior part of vertex silver pruinose and covered extensively with pale yellow-white setae (setae closer to occipital foramen are black); lower occipital setae shortish, bright yellow. Palpus two-segmented, basal segment small and covered with bright yellow setae, terminal segment greatly swollen (length less than twice breadth) and covered with long black setae except basally where setae are bright yellow and on a somewhat flattened medial surface adjacent to clypeus, which appears completely asetose. Proboscis dark red-brown (tip red-orange, with redorange setae), short and broad (a little longer than twice breadth) with labella rounded distally, and with dorsal ridge-like flange; basal parts covered with bright yellow setae. Thorax: Mesonotum dark red-brown to black, posterior part of postpronotal lobe bright orange and postalar callus red-brown; major macrosetae not evident, but surface entirely covered with pale yellow setae, a few similarly developed black setae are hidden amongst these (positioned where one normally expects to find the usual well-developed macrosetae). Scutellum similar in coloration and setation to mesonotum, no obvious macrosetae. Pleura dark red-brown to black (somewhat obscured by legs) covered with yellow setae except for hypopleuron and central part of anepisternum which have black setae. Katatergal setae long, spread out and ‘fan-like’ such that orange-brown halteres are somewhat obscured. Postmetacoxal area entirely sclerotised. Legs: Femora, tibiae and tarsi robust, tarsomeres generally short (those of pro- and mesothoracic legs twice as broad as long); claws black; pulvilli brown, slightly shorter than claws; empodium dark brown, half as long as claws. Femora and tibiae with long, pale yellow and black setae; anterior surfaces mainly pale yellow setose, posterior surfaces mainly black setose. Tarsi, especially those of meso- and metathoracic segments, almost entirely black setose; dorsal surfaces of metathoracic tarsomeres with long pale yellow setae among more numerous, shorter, black ones. Wing: Length (from humeral cross-vein to tip) – 11.4 mm, greatest breadth – 5.0 mm. Membrane more or less transparent, but slightly brownyellow stained adjacent to veins, especially in the subcostal area beyond mid-length. Costa extends around wing margin ending where A 1 reaches wing margin (i.e. anal lobe and alula not bordered by extension of C). Cells r 1, r 5, m 3 and cup closed and stalked; rm cross-vein situated very near proximal end of discal cell. Vein R 4 has tiny ‘spur vein’ basally ( Fig. 7 ). Both wings essentially similar (i.e. no notable variation exists).

Abdomen: Dark red-brown to black. Tergites mainly pale yellow setose (some black setae laterally); T8 greatly reduced to narrow sclerotised ring bordered by extensive areas of membrane. Sternites mainly black setose (tufts of longish yellow setae present laterally on S4 and more distal sternites); S3 uniquely equipped with well-developed median protrusion covered with many tightly-packed black setae ( Fig. 6 ).

Male terminalia ( Figs 8–16 ): S8 enlarged, positioned adjacent to fused gonocoxites (i.e. indicating no or very little rotation of the terminalia relative to more anterior parts of abdomen); epandrium (T9) almost circular in dorsal view (i.e. not modified in any way to assist in clasping female during copulation), only distal part setose. Proctiger composed of elongate, setose ventral lamellae (S10) and short, setose dorsal lamellae (T10) not extending beyond anus; dorsal lamellae divided into two sets of lobes, a median lobe lying adjacent to anus and a lateral, cercus-like lobe jutting out at almost right-angles to body. Gonocoxites with two distally directed lobes fused basally with apparent remains of hypandrium, such that they form a rather flat U-shaped structure (viewed ventrally); outer lobe of gonocoxite with central tuft of setae and acute distal apex; medial lobe relatively asetose and with well-sclerotised, somewhat club-shaped distal region bearing a strong down-turned process. Gonostylus fairly broad at midlength, with somewhat truncated distal end. Aedeagus with large proximal apodeme (whose length exceeds length of sheath and prongs combined); sheath somewhat longitudinally compressed, strongly sclerotised and lobed anteriorly (two lateral lobes and a central lobe projecting over prongs); prongs short, three in number, of similar length and not projecting beyond central lobe of sheath.

Female: Unknown.

Note: The holotype has a number of lepidopteran scales trapped amongst its setae – suggesting that the species may feed on lepidoptera. However, as Van Son was an active lepidopterist it seems far more likely that the specimen was collected in a trap designed for lepidoptera or perhaps stored amongst lepidopteran specimens prior to being pinned. Material examined: SOUTH AFRICA: 1ơ holotype, ‘Fernwood / Brits [25˚38'S:27˚47'E] Distr. / 6 Febr. 1944 / G. van Son’, ‘ Holotype ơ / Afromelittodes / solis / Oldroyd & v Bruggen / 1963’, ‘ Afromelittodes / solis / Oldroyd & v Bruggen / Holotype No. 958’ (NMSA). Note: The solis holotype was originally housed in the Transvaal Museum (Pretoria), but was subsequently transferred to the Natal Museum when the Transvaal Museum’s entire Diptera collection was exchanged for a collection of Lepidoptera.

Distribution: Known only from the type-locality near Brits.

Figures

Figs 1–7. Afromelittodes species. 1–5. A. mimos sp. n. (Olifantshoek holotype). 1. Head, lateral (no setae shown). 2. Palpus (left). 3. Antenna (left lateral, no setae shown). 4. Wing (right). 5. S3, lateral, showing medial setose tubercle.6–7. A. solis Oldroyd & Van Bruggen, 1963.6. S3, lateral, showing medial tubercle near hind margin. 7. Detail of venation showing ‘spur vein’ at base of R4. Scale lines 1 mm (figure numbers given). Abbreviations: S = sternite.

Figs 8–12. Afromelittodes solis Oldroyd & Van Bruggen, 1963. Male terminalia (Brits holotype): 8. Lateral. 9. Epandrium and proctiger, dorsal.10. S8, ventral.11. Genital bulb, ventral.12. Proctiger, ventral. Scale line 1 mm (for all figures).Abbreviations: ep = epandrium, gs = gonostylus, gx = gonocoxite, hy = hypandrium, S = sternite, T = tergite.

Figs 13–16. Afromelittodes solis Oldroyd & Van Bruggen, 1963. Male terminalia (Brits holotype): 13–14. Aedeagus. 13. Lateral. 14. Ventral. 15–16. Gonopodite (left). 15. Lateral. 16. Medial. Scale line 1 mm (for all figures). Abbreviations: ap = apodeme, gs = gonostylus, gx = gonocoxite, pr = prongs, sh = sheath.

Fig. 30. Distribution of Afromelittodes species. A. solis (square), A. mimos (triangles). Distribution of savanna biome indicated as shaded region.