Atherigona nesshurstensis, 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 : 887-888

Atherigona nesshurstensis sp. n.

Fig. 55

Etymology: Named for the type locality Nesshurst farm, near Harrismith in the Free State, South Africa.

Diagnosis: This species is similar to A. dentifolia Dike, 1989 , but differs from it by having a bifurcate hypopygial prominence compared to that of A. dentifolia which is bilobate. The trifoliate process has its median piece strongly dilated on apical half in posteriorview and somewhat dilated throughout its length in profile, compared to A. dentifolia which has its median piece filiform throughout.

Description:

Male. Measurement s: Body length: 3.596 mm; wing: 2.816 mm; r­m crossvein ratio: 0.338.

Head: Ground colour dark. All head setae and setulae infuscated. Occiput grey dusted throughout with narrow median part glossy, also laterally silver-grey dusted. Ocellar triangle grey dusted. Frontal vitta infuscated. Frontal plate silver-grey dusted throughout with three pairs of proclinate frontal setae and two pairs of orbital setae. Parafacial silver-grey dusted, at narrowest wider than aristal base. Scape and pedicel ferruginous, postpedicel and arista infuscated. Palpus yellow, apex truncated and dilated with hyaline hairs.

Thorax: Ground colour dark. Postpronotal lobe gold dusted, with three setae and 10 setulae. Pleura entirely grey dusted; Proepisternum inconspicuous and gold dusted. Scutum grey dusted throughout, with three 2-4 dorsocentral vittae, stopping before scutellum. Scutellum grey dusted; one pair of basal setae, one pair of discal setae and four discal setulae, one pair of subbasal setae and one pair of apical setae (subbasal pair 0.75× apical pair).

Legs: All legs yellow except for fore femur with dorsal dark marking near apex, fore tibia entirely infuscated except for extreme base and fore basitarsus together with following tarsal segment, which are also 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 with two large dark markings and a very much expanded median vitta that touches the inside edges of both, giving it an almost triangular appearance; tergite 3 two large dark oblong markings taking up over two thirds of dorsal surface, also with expanded median vitta that is almost touching the inside edges of other markings; tergite 4 with small round markings, taking up a third of dorsal surface, basal edge of tergite having a wide dark marking across most of surface; tergite 5 immaculate. Hypopygial prominence bifurcated. Trifoliate process stem 2× the length of the apical process; trifoliate process infuscated except for hood and stem which are light brown; median piece strongly dilated at apex posterior view, linear in lateral view; lateral plates 2× as wide as median piece in profile, with inner lobes. Surstylus with slight infuscation at base, and as strongly infuscated at apex as trifoliate process.

Female. Unknown.

Holotype ♂: SOUTH AFRICA: Free State: Harrismith, Nesshurst farm, 28°26'53.3"S 29°09'14.2"E, Leucosedea [ Leucosidea ] -scrub & stream bed, 17–18.ix.2009, A.H. Kirk-Spriggs, Malaise trap ( BMSA (D) 11073).

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.