Atherigona convexa, Muller, 2015

Muller, B. S., 2015, Illustrated key and systematics of male South African Atherigona s. str. (Diptera: Muscidae), African Invertebrates 56 (3), pp. 845-845 : 865-866

Atherigona convexa sp. n.

Fig. 57

Etymology: From the Latin convexus (arched outward), referring to the convex apex of the median piece of the trifoliate process.

Diagnosis: This species is very similar to Atherigona oryzae Malloch, 1925 , with A. oryzae keying to A. convexa in this manuscript key. However, A. convexa differs from A. oryzae in the following aspects: fore femur immaculate vs. having a dark marking apically; median piece of the trifoliate not membraneous as in oryzae; the stem of the trifoliate process linear compared to being swollen in A. oryzae ; A. convexa with wing without a dark marking in area surrounding Sc­R 1.

Description:

Male.

Measurement s: Body length: 3.08 mm; wing: 2.64 mm; r­m crossvein ratio: 0.426.

Head: Ground colour dark. All head setae and setulae infuscated. Occiput silver-grey dusted throughout with narrow median part glossy, also laterally silver-grey dusted. Ocellar triangle grey dusted. Frontal vitta infuscated with dull reddish suffusion. Frontal plate silver-grey dusted throughout with three pairs of proclinate frontal setae and two pairs of orbital setae. Parafacial golden-silver dusted, at narrowest only slightly wider than aristal base. Scape and pedicel infuscated with ferruginous margins, postpedicel infuscated except for very narrow basal area. Arista brown. Palpus yellow on apical half, infuscated on basal half, apex truncated and dilated with hyaline hairs.

Thorax: Ground colour dark. Postpronotal lobe gold dusted anteriorly and silver-grey posteriorly, with three setae and 10 setulae. Pleura entirely silver-grey dusted; Proepisternum inconspicuous and gold dusted. Scutum grey dusted throughout, with three faint 2-4 dorsocentral vittae, stopping before scutellum. Scutellum grey dusted; one pair of basal setae, one pair of discal setae and nine discal setulae, one pair of subbasal setae and one pair of apical setae (subbasal and apical setae equal).

Legs: All legs yellow except for apical third of fore tibia and fore basitarsus together with following tarsal segment, which are infuscated.

Leg chaetotaxy: Fore tarsi without any specialised chaetotaxy. Wings: Hyaline. Veins brown. Knob of halteres white with stalk yellow. Calypters white.

Abdomen: All tergites yellow; tergite 1+2 immaculate; tergite 3 with a pair of large oblong marks, taking up two thirds of dorsal surface, with the rest being grey dusted; tergite 4 with small round markings, taking up a third of dorsal surface; tergite 5 immaculate. Hypopygial prominence bifurcated. Trifoliate process stem 3× the length of the apical process; lateral plates infuscated, all other parts brown; median piece strongly dilated at apex in profile and in posterior view; lateral plates appearing just as wide as median piece dilation in profile, with small inner lobes in some specimens, in some others difficult to perceive. Surstylus not infuscated.

Female. Unknown.

Holotype ♂: SOUTH AFRICA : KwaZulu­Natal: Ndumo Game Reserve , Shokwe area, 26°52.125'S 32°13.731'E, Ficus forest, 30.xi–4.xii.2009, A.H. Kirk-Spriggs, Malaise trap ( BMSA (D) 16351).

Paratype ♂: SOUTH AFRICA : KwaZulu­Natal: Ndumo Game Reserve , main road, 26°54.288'S 32°17.974'E, Sand and broad-leafed deciduous forest, 4–8.xii.2009, A.H. Kirk-Spriggs, Malaise trap ( BMSA (D) 17545) .

Other material examined: Gauteng: 2♂ Johannesburg , 18.i.1953, Paterson ( NHMUK) ; Free State: 1♂ Brandfort, Florisbad Research Station , 28°46.039'S 26°04.234'E, Acacia Savanna , 4–6.iv.2009, A.H. Kirk-Spriggs, Malaise trap ( BMSA (D) 05584) .

Distribution: South Africa.

Figures

Figs 55–63. Atherigona spp.: trifoliate process and hypopygial prominence of (55) A. nesshurstensis sp. n.; (56) A. vernoni sp. n.; (57) A. convexa sp. n.; (58) A. rimapicis sp. n.; (59) A. falkei Deeming; (60) A. danielssoni sp. n.; (61) A. tigris sp. n.; (62) A. stuckenbergi sp. n.; (63) A. steeleae van Emden. Not to scale.