Gonioscelis nigripennis Ricardo, 1925

Londt, Jason G. H., 2004, A review of the afrotropical genus Gonioscelis Schiner, 1866 (Diptera: Asilidae), with descriptions of new species, African Invertebrates 45, pp. 21-124 : 74-75

Gonioscelis nigripennis Ricardo, 1925

Figs 15 , 89–91 , 149

Gonioscelis nigripennis Ricardo, 1925: 269–270 ; Engel 1925: 173–174; Oldroyd 1974: 39.

Redescription: Based primarily on syntype ^ ( BMNH), male structures described from syntype ơ ( SAMC) .

Head: Antenna dark red-brown to black, setae mostly black. Facial swelling poorly developed, mystax uniform dark red-brown to black, setae in dorsal half not as well developed as those in ventral half. Frons and vertex weakly red-gold pruinose. Ocellar tubercle apruinose with black oc. Occiput silver pruinose except for apruinose areas behind vertex, setae black dorsally, dark red-brown ventrally. Proboscis and palpus dark red-brown with dark red-brown setae.

Thorax: Dark red-brown to black, largely apruinose, but with small patches of silver pruinescence. Postpronotal lobes not contrasting in colour with adjacent mesonotum, with 2–3 long black setae. Mesonotal setae black: ac tiny; approx. 10 pairs dc, clearly extending anterior of transverse suture; 2 npl; 2 sa; 2 pa. Scutellum dark red-brown to black, with 2 black mrg sct. Wing length 8.4 mm, membrane mostly blackish. Legs: Femora dark red-brown with orange-brown distal tip, tibiae and tarsi orange-brown. Prothoracic coxa dark red-brown, apruinose, dark red-brown setose; femoral spur ( Fig. 15 ) very bluntly pointed (angle approx. 80°).

Abdomen: Tergites dark red-brown, T2–4 with silver pruinose hind margins and dorsal patches, setae tiny black. Sternites as tergites, appear apruinose (abdomen stuck to cellulose support and difficult to study).

Terminalia ( Figs 89–91 ): Long ep (epandrial lobes projecting far beyond proctiger), lobes tapering distally to tips equipped with 2–3 long strong macrosetae (left epandrial lobe cracked); gcx tapering distally with two distal projections and a few macrosetae; hyp, in ventral view, clearly longer than broad, constricted at mid-length before bilobed apex, each lobe carries a single long macroseta.

Variation: The few specimens available display little individual variation or sexual dimorphism.

Type material (all seen): NAMIBIA: 1ơ syntype, ‘Erikson’s Drift’ [17°15'S 14°40'E] / Kunene R. / Mar. 1923 ’ ~ ‘S.W. Africa / Mus. Exped.’, ‘ Gonioscelis / nigripennis / n sp Ricardo ơ Type’, ‘Holo- / type.’, ‘SAM-DIP / A008267’ (SAMC); 1^ syntype, same date but ‘Pres. by Cape Mus.’(BMNH); 2^ syntype, ‘Otjimbumbe [17°24'S 14°25'E] / Kunene R. / Mar. 1923 ’ ~ ‘S.W. Africa / Mus. Exped.’, ‘ Gonioscelis / nigripennis / n sp Ricardo [one incorrectly labelled as ơ], ‘SAM-DIP / A008268’ (SAMC).

Type locality: Namibia, Erikson’s Drift. Notes: As Ricardo (1925) designated more than one type, all her specimens must be considered syntypes. There is no need to designate a lectotype. Engel (1925) records ‘?^ Namaqua. O’okiep, in coll Hermann. Zoolog. Staatsammlung, München.’ (ZSMC). This specimen has been studied and is listed under melas .

Distribution, phenology and biology (Tables 1–2, Fig. 149 ): Known from only two localities along the Kunene River between Namibia and Angola. These places being within the Savanna biome. All known specimens were collected in March.

Similar species:A member of the large and widely distributed group of species possessing a poorly defined facial gibbosity. The species has highly distinctive male genitalia. The hypandrium is particularly characteristic in having inwardly curved distal lobes, each equipped with a single apical macroseta. There is, however, only a single known male and so the extent of possible variation cannot be assessed.

Figures

Figs 10–17. Gonioscelis species, left prothoracic femur, showing variation in spur development and method of measuring spur angle (16–17). 10. G. melas sp. n. (25 km N Kamieskroon). 11. G. chloris sp.n. (4 km SW Clanwilliam). 12. G. longulus Ricardo, 1925 (Paul Roux). 13. G. cuthbertsoni sp. n 7 km SE Angwa Bridge). 14. G. macquartii Jaennicke, 1867 (Nguruma). 15. G. nigripennis Ricardo, 1925 (Erikson’s Drift). 16. G. xanthochaites sp. n. (Aus). 17. G. hadrocantha sp. n. (Roçadas). Scale lines = 1 mm.

Figs 89–100. Gonioscelis male genitalia. 89–91. G. nigripennis Ricardo, 1925 (Erikson’s Drift syntype), left epandrial lobe fractured. 89. Lateral. 90. Dorsal. 91. Ventral. 92–94. G. phacopterus Schiner, 1867 (Clifton). 92. Lateral. 93. Dorsal. 94. Ventral. 95–97. G. pickeri sp. n. (Biedouw valley paratype). 95. Lateral. 96. Dorsal. 97. Ventral. 98–100. G. pruinosus Ricardo, 1925 (Narok syntype). 98. Lateral. 99. Dorsal. 100. Ventral. Scale lines = 1 mm.

Figs 148–149. Distribution of Gonioscelis species found only in southernAfrica. 148. closed circle = genitalis, open circle = longulus, closed square = maculiventris, open square = phacopterus. 149. closed circle = lacertosus, open circle = nigripennis, closed square = ramphis, open square = truncatus.