Gonioscelis cuthbertsoni, Londt, 2004

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 : 40-41

Gonioscelis cuthbertsoni sp. n.

Figs 7 , 13 , 36–38 , 146

Etymology: Named after Alexander Cuthbertson who contributed to our knowledge of Zimbabwean asilids.

Description: Based primarily on holotype ơ (NMSA).

Head: Antenna brown-yellow, setae yellow-brown. Facial swelling poorly developed, mystax uniform pale yellow-white, present on gibbosity and immediately below antennal sockets. Frons and vertex strongly gold pruinose. Ocellar tubercle largely apruinose with yellow oc. Occiput strongly gold pruinose with silver eye margins, setae pale yellow-white. Proboscis and palpus dark red-brown, white setose.

Thorax: Mesonotum brown-yellow with dark red-brown medial stripe and posterolateral spots, strongly silver-gold pruinose, pleura similar but with a dark red-brown anepisternal spot. Postpronotal lobes brown-yellow, not contrasting with adjacent mesonotum, with approx. 6 yellow macrosetae and smaller setae. Mesonotal setae yellow: ac not evident; approx. 8 pairs dc, just extending anterior of transverse suture; 3–4 npl; 3 sa; 3 pa. Scutellum brown-yellow, with 4 yellow mrg sct. Wing length 7.3 mm, membrane mostly pale yellow, microtrichia slightly darker brown at distal forks and crossveins giving wings a weakly spotted appearance. Legs: Yellow except for brown area anteroproximally on prothoracic femur, setae yellow except for a few dark red-brown ones on spur and ventrally on some tarsomeres. Prothoracic coxa brown-yellow, thinly gold pruinose, pale yellowwhite setose; femoral spur ( Fig. 7 ) moderately pointed (angle approx. 45°).

Abdomen: Tergites yellow, thinly silver-gold pruinose, yellow setose. Sternites similar to tergites.

Terminalia ( Figs 36–38 ): Lobes of ep project distally to about the same level attained by proctiger, lobes tapering distally in lateral aspect, each with fine setae distally; gcx with two long projections, the ventral one with a few moderately developed macrosetae ventrally; hyp, in ventral view, clearly broader than long, tapering slightly to two wellseparated terminal lobes each with fine setae.

Variation: The Angwa Bridge material appears to have been mounted from alcohol as a small degree of distortion is evident. A reasonably uniform species. Some topotypic specimens have dark red-brown ocellar setae. There is a degree of variation in the extent of dark red-brown coloration on mesonotum and legs.

Type material: ZIMBABWE: 1ơ holotype, 1ơ 1^ paratypes, ‘ Zimbabwe #2 / 7km SE Angwa Bridge / 16 08'S 30 15'E / Date: 27.viii.1988 / R. Peveling & J. Weyrich’; 1ơ 1^ paratypes, ‘ Zimbabwe #3 / 7km SE Angwa Bridge / 16 08'S 30 15'E / Date: 10.ix.1988 / R. Peveling & J. Weyrich’; 4ơ paratypes, ‘ Zimbabwe #4 / 7km SE Angwa Bridge / 16 08'S 30 15'E / Date: 2.viii.1988 / R. Peveling & J. Weyrich’; 1^ paratype, ‘ Zimbabwe #5 / 7km SE Angwa Bridge / 16 08'S 30 15'E / Date: 19.viii.1988 / R. Peveling & J. Weyrich’; 1ơ paratype, ‘ Zimbabwe #5 / 7km SE Angwa Bridge / 16 08'S 30 15'E / Date: 3.ix.1988 / R. Peveling & J. Weyrich’; 1ơ paratype, ‘ Zimbabwe #8 / 7km SE Angwa Bridge / 16 08'S 30 15'E / Date: 5.ix.1988 / R. Peveling & J. Weyrich’; 2^ paratypes, ‘ Odzi [18°58'S 32°23'E] / Umtali District / S. Rhodesia / Aug. 1931 / P.A. Sheppard’; 1^ paratype, ‘S. Rhodesia / Hopefountain [Hope Fountain 20°16'S 28°39'E] / 30.8.22 / Roy Stevenson’; 1^ paratype, ‘ Hopefountain / S. Rhodesia / 12.ix.1922 / Swinburne & / Stevenson. ’, ‘2 / 3245 ’.

Other material: ZIMBABWE: 1ơ, ‘Mazoe River / Shamva [17°19'S 31°34'E] / S. Rhodesia / Dept. Agric. / 1/9/1935 ’, ‘W.C. Williams / Collector’ (NMNH); 1^, ‘Gota Gota [Hill 17°18'S 31°54'E] / Urungwe / Dept. Agric. / S Rhodesia / 17/9/1938 ’, ‘W.L. Williams / collector’, ‘ Gonioscelis / submaculatus / Speis. / det. E.O. Engel’ (ZSMC); 1ơ, ‘Triangle [21°02'S 31°27'E] / So. Rhod. / No. 119 / 19-ix-1963 / Coll. A.L. Moore’ (NMNH); 1^, ‘Triangle / So. Rhod. / No. 120 / 19-ix-1963 / Coll.A.L. Moore’ (NMNH); 1ơ 1? (? ^ in cop), ‘Triangle / So. Rhod. / No. 144 / 19-ix-1963 / Coll. A.L. Moore’ (NMNH); 1?, ‘Triangle / So. Rhod. / No. 187 / 21-ix-1963 / Coll.A.L. Moore’ (NMNH); 1ơ, ‘Triangle / So. Rhod. / No. 195 / 21-ix-1963 / Coll. A.L. Moore’ (NMNH); 1^, ‘Triangle / So. Rhod. / No. 196 / 21-ix-1963 / Coll. A.L. Moore’ (NMNH).

Type locality: Zimbabwe: 7 km SE Angwa Bridge.

Distribution, phenology and biology (Tables 1–2, Fig. 146 ): Known from a few savanna localities in Zimbabwe. Material has been collected in August and September (i.e. early spring in this summer-rainfall region). Cuthbertson (1939) published a brief comment, under the name submaculatus , that I believe pertains to cuthbertsoni , as material collected by Williams at Gota-Gota (see above), and incorrectly identified by Engel as submaculatus , has been studied and confirmed as belonging to cuthbertsoni . His entire comment is cited here – ‘Widely distributed in the low lying arid parts of the Colony [ Zimbabwe, then Southern Rhodesia], and common in the late dry season during August and September. The flies rest on the ground and attack passing insects. Prey: male with small fly, Gobertina picticornis Big. (Stratiomyiidae) in September, 1938, at GotaGota camp, Urungwe (W. L. Williams).’

Similar species:A member of the large and widely distributed group of species possessing a poorly defined facial gibbosity. The short hypandrium with widely separated apical lobes is distinctive and separates the species from all others. The species has weakly spotted wings like those of tomentosus .

Figures

Figs 6–9. Gonioscelis species, wing, showing some variation encountered. 6. G. ventralis Schiner, 1867 (Vaalbos National Park) microtrichial colours results in central parts of cells appearing darker than areas adjacent to veins. 7. G. cuthbertsoni sp. n. (Angwa Bridge) showing very weak spotting at forks and crossveins.8. G. punctipennis Engel, 1925 (10 km W Garies) showing strong spotting at forks and crossveins. 9. G. melas sp. n. (31 km N Sutherland) showing generally dark wings caused mainly by black microtrichia.

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 30–41. Gonioscelis male genitalia. 30–32. G. chloris sp. n. (Clanwilliam paratype). 30. Lateral. 31. Dorsal. 32. Ventral. 33–35. G. congoensis Oldroyd, 1970 (holotype). 33. Lateral. 34. Dorsal. 35. Ventral. 36–38. G. cuthbertsoni sp. n. (Angwa Bridge paratype). 36. Lateral. 37. Dorsal. 38. Ventral. 39–41. G. engeli sp. n. (holotype). 39. Lateral. 40. Dorsal. 41. Ventral. Scale lines = 1 mm.

Figs 146–147. Distribution of Gonioscelis species found only in southern Africa. 146. closed circle = bykanistes, open circle = cuthbertsoni, closed square = hadrocantha, open square = mantis. 147. closed circle = engeli, open circle = scapularis, closed square = ventralis, open square = xanthochaites.