Atherigona libertensis, 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 : 879-880

Atherigona libertensis sp. n.

Fig. 29

Etymology: From the Latin libertes (freedom), named for the province in which the type locality is situated, i.e. the Free State.

Diagnosis: This species is similar to A. angustiloba in terms of general appearance and shape of the hypopygial prominence. A. libertensis differs, however, with regards to the shape and colour of the trifoliate process, which is entirely hyaline compared to the entirely infuscated process of A. angustiloba ( Fig. 29 vs. Fig. 30 ). The trifoliate process is visually similar to those of A. naqvii Steyskal, 1966 and A. cinarina due to the coloration and the presence of a pair of long hyaline setulae at the apex of the median piece, but differs overall structurally, not having any emargination at the apex as with the other two species ( Fig. 29 vs. Figs 36 & 37 ).

Description:

Male.

Measurement s: Body length: 3.84 mm; wing: 3.12 mm; r­m crossvein ratio: 0.405.

Head: Ground colour dark. All head setae and setulae infuscated. Occiput grey dusted posteriorly with narrow median part glossy, laterally also dusted. Ocellar triangle grey dusted, sub-shining. Frontal vitta infuscated, apical ⅓ appearing ferruginous. Frontal plate silver-grey dusted on apical two thirds, basally grey dusted, with three pairs of proclinate frontal and two pairs of orbital setae, bases of setae appearing slightly glossy. Parafacial silver-grey dusted, only somewhat wider than aristal base. Scape and pedicel infuscated with ferruginous apex. Postpedicel infuscated. Arista infuscated. Palpus yellow except for infuscated basal third; apically dilated and truncated, with hyaline setulae.

Thorax: Ground colour dark. Postpronotal lobe grey dusted except for ventrolateral margins which are golden dusted, lobe with three setae and eight setulae. Pleura grey dusted, except for area where katepisternum, anepisternum and anepimeron converge. Proepisternum not conspicuous. Scutum grey dusted, with three faint and barely visible 2-4 dorsocentral vittae, not extending to the scutellum; Scutellum grey dusted; one pair of basal setae, one pair of discal setae and six discal setulae, one pair of subbasal setae and one pair of apical setae, comparison between subbasal and apical pair not possible due to damage.

Legs: All legs yellow with the exception of the fore femur having a dark mark on apical posterior surface, and apical third of fore tibia and entire fore tarsi which is infuscate. Leg chaetotaxy: apical three fore tarsal segments with long dorsal setulae, at least as long as segments are wide.

Wings: Hyaline, except for slight brown smoky suffusion at apex of Sc­R 1. Veins brown. Halteres with white knob and yellow stalk. Calypters white.

Abdomen: All tergites yellow; tergite 1+2 with faint median vitta, not reaching the apical margins; tergite 3 with two large dark-brown oblong marks taking up just over two thirds of surface, vitta present and same length as large marks; tergite 4 with two small round markings, taking up a third of dorsal surface, with dark vitta that spans the entire length of segment; tergite 5 immaculate. Hypopygial prominence knob-shaped with two anteriorly projecting tubercles. Trifoliate process stem 2.9× the length of the apical process; trifoliate process and all setulae hyaline except for the edges of lateral plates and lateral edges of hood which are infuscated; median piece with slight club-like appearance, same shape in profile, apically with two long hyaline setulae (approximately the same length as entire median piece) and two smaller setulae at centre; lateral plates obavate in profile, no inner lobes present. Surstylus not infuscated. Female. Unknown.

Holotype ♂: SOUTH AFRICA: Free State: Harrismith, Scotland farm, 27°58'59.5"S 29°37'09.8"E, dense Leucosedea [ Leucosidea ] dominated scrub, 10–12.xi.2009, A.H. Kirk-Spriggs, Malaise trap ( BMSA (D) 12760).

Distribution: South Africa.

Figures

Figs 28–36. Atherigona spp.: trifoliate process and hypopygial prominence of (28) A. oblonga sp. n.; (29) A. libertensis sp. n.; (30) A. angustiloba van Emden; (31) A. albicornis sp. n.; (32) A. occidentalis Deeming; (33) A. kirkspriggsi sp. n.; (34) A. perfida Stein; (35) A. chirinda Dike; (36) A. cinarina Séguy. Not to scale.

Figs 37–45. Atherigona spp.: trifoliate process and hypopygial prominence of (37) A. naqvii Steyskal; (38) A. ruficornis Stein; (39) A. flaviheteropalpata sp. n.; (40) A. latibasilaris sp. n.; (41) A. mitrata Séguy; (42) A. bedfordi van Emden; (43) A. ochracea Deeming; (44) A. theodori Hennig; (45) A. rubricornis Stein. Not to scale.