Xestomyza stuckenbergi, Hauser, 2012

Hauser, Martin, 2012, A new species of Xestomyza Wiedemann, 1820 from South Africa, with a key to the genera of Xestomyzinae (Diptera: Therevidae), African Invertebrates 53 (1), pp. 175-175 : 180-184

publication ID	https://doi.org/ 10.5733/afin.053.0111
persistent identifier	https://treatment.plazi.org/id/956BD905-FFE9-C903-FE37-FDC4FED6FE21
treatment provided by	Felipe
scientific name	Xestomyza stuckenbergi
status	sp. nov.

Treatment

Xestomyza stuckenbergi sp. n.

Figs 5–8 View Figs 5, 6 View Figs 7, 8 , 12–17 View Figs 9–12 View Figs 13–19 , 20 View Figs 20, 21

Etymology: The species is named after Brian Stuckenberg, in honour of his leading role in African Dipterology for many decades.

Diagnosis: This species is significantly smaller than X. lugubris and is characterized by the grey pubescence covering the entire body and the differences in the male terminalia.

Description:

Male.

Body length: 5.5–6.2 mm; wing length: 5.5–6.9 mm.

Head: Entirely covered in silver pubescence; dichoptic with eyes separated by 2× the distance between hind ocelli ( Fig. 7 View Figs 7, 8 ); eye bare, ommatidia homogeneous in size; setae on head strong, black, except finer and white on gena, palpus and proboscis. Antenna inserted on central facial protrusion, which is silver pubescent dorsally and ventrally as on remainder of head, but dark brown pubescent laterally ( Fig. 5 View Figs 5, 6 ). Scape 4.5× as thick as long; clothed in silver pubescence; dorsoapical three-quarters and ventroapical third with strong, black, bristlelike setae ( Fig. 20 View Figs 20, 21 ); setae on dorsobasal quarter and ventrobasal twothirds of virtually same length; pedicel ovoid, with ring of stiff black setae longer than length of pedicel; flagellomere 1 pearshaped, covered in short erect setae; second flagellomere cylindrical, with apical arista. Proboscis straight, long, virtually as long as scape; palpus long, twosegmented, both covered with numerous long, black setae admixed with some white setae. Macrosetae: 2 notopleural, 1 supra-alar, 1 postalar, 6 dorsocentral, 1 scutellar (all black).

Thorax and pleuron: Entirely covered in silvery-grey pubescence, except for a medial brown fascia along length of scutum, bifurcated in anterior quarter by a silver line, and brown pubescent lateral part of scutum. Scutum with sparse black erect setae; pleuron with sparse fine white setae ( Fig. 7 View Figs 7, 8 ). Prosternal depression with numerous long white setae. Wing dark brown, except lighter area in discal area, comprising basal part of cell r 5, apical part of cell d and basal part of cell m 1 ( Figs 5, 6 View Figs 5, 6 ); apical half of wing with veins surrounded by lighter coloration; visible coloration chiefly caused by colour of microtrichia that are either black or yellow; all veins brown, except subcostal vein yellow. Haltere yellowbrown, lighter towards apex. All coxae black with silver pubescence. All femora dark brown with short appressed black setae and some longer erect white setae in ventral parts. All tibiae light brown with appressed short black setae and erect bristlelike setae. Tarsi brown, darker towards apex.

Abdomen: Blackish brown, clothed in grey pubescence. Intersegmental membranes of segments 2–5 white. Medially, setae short, black, semierect; laterally and ventrally, setae white. Terminalia: Dark brown, with a fingerlike extensions on each gonocoxite; each one of these two extensions with four apical macrosetae; apical part of gonocoxite (gonocoxal ring) open ( Fig. 14 View Figs 13–19 ); hypandrium free, large, with 4 or 5 pairs of long setae ( Fig. 13 View Figs 13–19 ); aedeagus with ventral apodeme long and forked, dorsal apodeme reduced and apical cap extended and winglike ( Figs 16, 17 View Figs 13–19 ).

Female.

Body length: 5.2–6.4 mm; wing length: 4.5–5.3 mm.

Similar to male ( Figs 6 View Figs 5, 6 , 8 View Figs 7, 8 ), except setae on frons and scape distinctly weaker ( Fig. 9 View Figs 9–12 ). Frons width equal in both sexes (but narrower in males vs females of X. lugubris ).

Holotype: ♂ “R.S.A.: W Cape #110 / 10km S Lamberts Bay / 32°11’S: 18°19’E 150m / Date: 1.ix.1995 / coll: J. & A. Londt / Costal dunes” (MEI 164792, NMSA). GoogleMaps

Paratypes: same label information as holotype (5♂ MEI 164780 ( NMSA), 164783 ( CSCA), 164784 ( NMSA), 164786 ( NMSA), 164789 ( NMSA); 4♀ MEI 163370 ( NMSA), 164779 ( NMSA), 164787 ( NMSA), 164791 ( NMSA)) .