Xenomyia hirtibasis (Bigot), 1885

Xenomyia hirtibasis (Bigot), 1885 View in CoL

Redescription

Male. Length: body: 4.5–6 mm; wing: 4.0–5.0 mm. ( Figs 46–48 View FIGURES 46–51 )

Color: General color brown, with greyish-blue pollinosity. Frontal vitta and fronto-orbital plate velvety dark brown. Face and gena grey-blue pollinose. Antennae, arista and palpus dark brown. Scutum and scutellum dark brown, subshining, with postpronotum and notopleuron greyish-blue pollinose. Pleura greyish-blue pollinose, upper half of anepisternum dark brown. Calypters creamy-white. Halter yellow. Wing smoky brown. Legs brown with greyish-blue pollinosity. Abdomen dark brown, with lateral greyish-blue pollinose areas in all tergites.

Head ( Figs 10 and 11 View FIGURES 10–15 ): Frontal vitta broad; fronto-orbital plate narrow. Eye bare. Ocellar setae present, well-developed. Inner and outer vertical setae strong. Postpedicel short, about 1.5 times the length of the pedicel. Arista long, pubescens, enlarged on basal third. Vibrissae long, with vibrissal setulae. Gena tall, about one third of eye height. Proboscis stout and bulbous, dusted, labellum with pairs of stout teeth ( Fig. 48 View FIGURES 46–51 ). Palpus somewhat dilated apically, flattened, slightly spoon-shaped.

Thorax: Acrostichal absent. Dorsocentrals 2:3. Intra-alars 1+0. Supra-alars 1, prealar absent. 1 postpronotal (the outer), the lobe covered with short dense setulae. Prosternum bare. Postpronotal 1, long. Notopleuron with 2 setae, the posterior seta one-third longer than anterior seta, without setulae. Anepisternum without a short seta in upper anterior corner. Katepisternals 1+1, the upper posterior seta strong. Anepimeron, katepimeron, meron, katatergite and anatergite bare. Posterior spiracle without setae on margins. Scutellum with a pair of sub-basal lateral and apical setae, the apical seta one-third longer than the basal seta; disc sparsely setulose, lateral margins and ventral surface bare.

Legs: ( Figs 17 View FIGURES 16–20 and 46 View FIGURES 46–51 ) Fore coxa greatly developed and with a dense tuft of numerous long fine setae on anterior surface; mid coxa with a row of long seta, mid femur with 4–6 fine and long posteroventral setae near base followed by a row of 7–8 pointed setae until two-thirds of the length. Hind femur with 3–5 long anteroventral setae on apical two-thirds. Hind tibia with a very long anterodorsal seta on basal third ( Fig. 17 View FIGURES 16–20 ). All tarsi long with claws long and strong.

Wing ( Figs 23 View FIGURES 21–26 and 46 View FIGURES 46–51 ): Membrane completely covered with microtrichia. Greater ampula dark brown. Veins bare except Costa. Both calypters glossiform, lower one about 1.4 times the length of the upper one.

Abdomen. Tergites with row of fine setae at margins of all tergites.

Genitalia ( Figs 27–32 View FIGURES 27–32 ): Sternite 5 a little taller than wide, with a deep anterior margin ( Fig. 27 View FIGURES 27–32 ). Sternite 6 asymmetric ( Fig. 28 View FIGURES 27–32 ). Cercal plate partially divided and surstylus as long as cercal plate ( Figs 29 and 30 View FIGURES 27–32 ).

Aedeagus with the epiphallus well-developed; phallapodeme long, narrow; pregonite long; postgonite shorter than pregonite; distiphallus membranous at apex ( Figs 31 and 32 View FIGURES 27–32 ).

Female: Similar to male, mainly differing in leg chaetotaxy. ( Figs 49–51 View FIGURES 46–51 ).

Legs: Fore coxa without a dense tuft of numerous long fine setae on anterior surface. Mid and hind femora practically without differentiated setae, except for a fine preapical dorsal seta on both femora. Hind tibia with the anterodorsal seta on basal third short and fine.

Ovipositor ( Figs 39 and 40 View FIGURES 39–41 ): Long, all tergites broad, well-developed, cercus about twice longer as long as the epiproct, with long setae on outer margin. Sternite 6 elongate-rectangular; sternite 7 a small plate; sternite 8 absent. The membrane between sternites 7 and 8 with microtrichia. Three rounded spermathecae.

Material examined. SOUTH AFRICA: Western Cape, Stellenbosch, Jonkershoek NR, t. Tweede Waterval, Eerste R., S33 o 59’44.7” E18 o 58’52.0”, 408 m, 02/xii/2018, LHGA & ACM, LHGA 201812022, 1 male and 1 female ( MNRJ); GoogleMaps Af. Eerste River , 325 m, S33 o 57’55.47” E18 o 55’55.95”, 02/xii/2018, LHGA & ACM, LHGA 201812021, 1 male ( MNB); GoogleMaps Tulbagh , Groot Winterhoek, Klein Wk, Secret Falls, 388m, S33 o 10’53.7” E19 o 07’20.9”, 05/xii/2018, LHGA & ACM, LHGA 201812051, 1 male, 1 female ( MNRJ), 2 females (NMB). GoogleMaps All in good conditions. Although adults were not observed preying, they were seen flying over areas where immature Simuliidae were collected.

Note. Described from male and female from South Africa, Cape, Cape of Good Hope. (OUMNH). The original description, in the genus Lispe , is very brief. Stein (1907) redescribed the species with more details mainly on the leg chaetotaxy and mentioned that the absence of setae on anepimeron should better positioned it in the genus Melanochelia Rondani (= Limnophora Robineau-Desvoidy ). Later, Emden (1951) saw the same specimen seen by Stein (1907) (designated by inference as lectotype by Pont 1980) and included the species in his key. More recently, Pont & Werner (2003) also included this species in their key for the Xenomyia of Southern Africa. One male from Western Cape, Buffelsbos forest, 33°54.154’S, 23°38.329’E, 400 m, indigenous montane forest (stream), Kirk-Spriggs, A.H. (BMSA(D)08463 is deposited at BMSA.