Neotherevella londti, Winterton & Irwin & Mortelmans, 2023

Winterton, Shaun L., Irwin, Michael E. & Mortelmans, Jonas, 2023, Revision of the dune-associated stiletto flies of the genus Neotherevella Lyneborg, 1978 (Therevidae, Therevinae), African Invertebrates 64 (2), pp. 109-138 : 109

Neotherevella londti sp. nov.

Figs 5 , 6 , 7 , 11E, F , 12E, F , 13E, F , 14C, E , 15

Holotype.

South Africa • male; Western Cape Province, Cape Vermont, nr. Onrus; [-34.4013, 19.1352]; 6 Apr 1979; J. Londt & B. Stuckenberg leg.; dune vegetation and sandy road; 3419AC; NMSA; MEI115849.

Paratypes.

South Africa • 3 males, 7 females; Western Cape Province, same data as holotype; NMSA, CSCA; MEI115850-6, 115857-9. • 3 females; Western Cape Province, Glencairn, pres. Simonstown; [-34.1646, 18.4291]; M. Bequaert leg.; R.I.Sc.N.B., 24.236; RBINS. • 5 males; Western Cape Province, Fish Hoek; M. Bequaert leg.; [-34.1449, 18.4323]; R.I.Sc.N.B,. 24.236; RBINS.

Diagnosis.

Male frons with dark maculae present, frontal maculae with elongate pile of erect macrosetae, male frons wider than ocellar tubercle at narrowest point; cell m3 open; all macrosetae black, elongate and numerous; two pairs of dorsocentral macrosetae; palpi crassate and acuminate; all femora with ventral macrosetae.

Description.

Body length: 8.0-8.5 mm (male), 7.5-8.5 mm (female). Head. Frons profile flat, wholly pubescent; vertex excavated (more so in male); male frons slightly wider than ocellar tubercle at narrowest point, female frons broad with eyes slightly narrowed dorsally; frontal pubescence silver ventrally, grey-tan dorsally, paired matte-black maculae with erect black setae (longer in male); postocular setae black, elongate, strongly curved anteriorly in a single row, additional setae irregularly arranged medially on occiput; male occiput relatively concave, pubescence silver with scale-like setae medially; antennal scape slightly longer than flagellum, slightly thickened, cylindrical, brown, overlain with grey pubescence, densely covered with large, dark setae; flagellum brownish-orange, darker distally; genal setae dark; palpus crassate, acuminate with extensive erect white and black setae. Thorax. Scutum pubescence grey-tan with brown mottling, erect filiform setae admixed with adpressed, white, scale-like setae, denser anteriorly (longer in male), thoracic macrosetae black and relatively elongate; scutellum concolourous with scutum; pleuron with dense silver-grey pubescence admixed with extensive, semi-erect, white, scale-like setae; anepisternum with brownish suffusion dorsally; coxae dark, overlain with silver-grey pubescence, setae white and black, macrosetae numerous, strong, black; femora dark brown, short black setae admixed with longer setae, sparse covering of white scale-like adpressed setae (denser in male), all femoral anteroventral and posteroventral macrosetae black, more numerous on hind femur, hind femur with 3-12 anteroventral macrosetae along entire length; tibiae and tarsi brown, macrosetae elongate, black; wing opaque yellow-tan and white with irregular dark brown markings in most cells; some individuals with a short, black macroseta distally on R1; cell m3 open; venation yellow basally along major veins, darker distally; haltere stem pale with knob mostly brown; scutal chaetotaxy: notopleural, 3; supra alar, 2; post alar, 1; dorsocentral, 2; scutellar, 2. Abdomen. Abdomen dark brown dorsally, grey pubescent laterally, dense pile of filiform erect and adpressed, scale-like setae, brown medially, white marginally on all tergites, denser laterally and posteriorly; female abdomen similar to male, except setal pile much sparser; acanthophorite spines black. Male genitalia. Dark brown with brown setae; epandrium sub-quadrangular, posterior margin thickened and posterolateral corners rounded; sternite 8 ovoid; gonocoxites with outer gonocoxite process relatively short, truncated; gonocoxal apodeme narrow; inner gonocoxal process rounded apically; gonostylus with small angular ridge medially; ventral lobe relatively large and spatulate; phallus with dorsal apodeme broad, ventral apodeme triangular; distiphallus narrow.

Etymology.

This species is named in honour of Jason Londt, who, along with Brian R. Stuckenberg, collected most of the known specimens.

Distribution.

South-western South Africa.

Ecology.

Neotherevella londti sp. nov. adults were collected on vegetated coastal sand dunes.

Conservation status.

Unknown; this species is known from two small series of specimens from a relatively small area in Western Cape region. The type locality has residential developments along the coast in dune habitats where this species is known.

Comments.

Neotherevella londti sp. nov. is unique in the genus in having crassate palpi, frontal maculae in both sexes and extensive dark, elongate macrosetae on the head, body and legs. Some individuals have a small macroseta present distally on wing vein R1, a feature found disparately in some distantly-related genera.

Figures

Figure 5. Neotherevella londti sp. nov., female A oblique view B lateral view.

Figure 6. Neotherevella londti sp. nov., male A oblique view B lateral view.

Figure 7. Neotherevella londti sp. nov. A male head, lateral view B female head, lateral view.

Figure 11. Neotherevella species, head, frontal view A Neotherevella kozlovi (Zaitzev, 1971 a), male B same, female C Neotherevella arenaria (Lyneborg, 1976), male D same, female E Neotherevella londti sp. nov., male F same, female G Neotherevella macularis (Wiedemann, 1828), male H same, female I Neotherevella maroccanus sp. nov., male.

Figure 12. Neotherevella species, male epandrium and sternite 8 A, B Neotherevella arenaria (Lyneborg, 1976) C, D Neotherevella kozlovi (Zaitzev, 1971 a) E, F Neotherevella londti sp. nov. G, H Neotherevella macularis (Wiedemann, 1828). Scale bar: 0.25 mm.

Figure 13. Neotherevella species, male gonocoxites (ventral view left, dorsal view right) with phallus in situ A, B Neotherevella arenaria (Lyneborg, 1976) C, D Neotherevella kozlovi (Zaitzev, 1971) E, F Neotherevella londti sp. nov. G, H Neotherevella macularis (Wiedemann, 1828). Scale bar: 0.25 mm.

Figure 14. Neotherevella species, male phallus A Neotherevella kozlovi (Zaitzev, 1971), lateral view B Neotherevella arenaria (Lyneborg, 1976), lateral view C Neotherevella londti sp. nov., lateral view D Neotherevella macularis (Wiedemann, 1828), lateral view E Neotherevella londti sp. nov., ventral view F Neotherevella macularis (Wiedemann, 1828), dorsal view. Scale bar: 0.25 mm.

Figure 15. Neotherevella distribution.