Neotherevella macularis (Wiedemann)

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 macularis (Wiedemann)

Figs 8 , 9 , 11G, H , 12G, H , 13G, H , 14D, F , 15

Thereva macularis Wiedemann, 1828: 558- Bezzi (1903: 209 [catalogue], 1906: 264 [catalogue]); Kertész (1909: 155 [catalogue]); Kröber (1912c: 254 [checklist], 1912d: 409 [redescription], 1913: 49, 58 [key, checklist], 1924a: 100 [possible synonymy], 1924b: 17 [synonymy]).

Neothereva macularis (Wiedemann, 1828)- Kröber (1937: 276 [combination change, catalogue]); Lyneborg (1976: 294 [redescription]); Steyskal & El-Bialy (1967: 53 [checklist]).

Neotherevella macularis (Wiedemann, 1828)- Lyneborg (1978: 76 [combination change], 1980: 319 [catalogue], 1989: 22 [catalogue]); El-Hawagry et al. (2011: 152 [catalogue]; Kettani et al. (2022: 213 [catalogue]).

Thereva citrina Becker, 1902: 35- Bezzi (1903: 208 [catalogue], 1906: 264 [catalogue]); Kertész (1909: 152 [catalogue]). syn. nov.

Neothereva citrina (Becker, 1902)- Kröber (1912b: 138, 139 [key, redescription], 1913: 42 [key, checklist], 1924a: 17 [key redescription], 1937: 276 [catalogue]).

Neotherevella citrina (Becker, 1902)- Lyneborg (1978: 76 [combination change], 1989: 22 [catalogue]); El Hawagry et al. (2011: 151 [catalogue]).

Neothereva angustifrons Kröber, 1912b: 139- Kröber (1913: 42 [key, checklist], 1924a: 100 [redescription, antennae figure], 1924b: 17 [key, redescription], 1929: 75 [catalogue, possible synonymy]).

Type material.

Thereva macularis Wiedemann, 1828- Holotype Sudan • female; Abyssina; Dr. Rüppell; SMF. Thereva citrina Becker, 1902- Lectotype Egypt • male; ZMHB. Neothereva angustifrons Kröber, 1912b- Holotype Egypt • male; ZMHB.

Other material.

Egypt • 1 male, 1 female; Giza Governorate, Abu [Abou] Rowash ; [30.0451, 31.0899]; 12 Sep 1924, 11 Mar 1925; Min. Agric. ( Egypt), R.M. leg.; AMNH; MEI084347-8 . Israel • 7 males, 1 female; Haifa District, Sdor Yam (nr. Caesarea ); [32.4831, 34.8985]; 30 m alt.; 14 Apr 1995; M.E. Irwin leg.; shifting coastal dunes; CSCA; MEI028294-5, 02827, 030658, 030661-2, 030667, 060671 • 2 males, 1 female; Southern District, Nizzamin [Nitsanim] Beach; [31.7368, 34.6148]; 15 Apr 1995; M.E. Irwin leg.; 43 m; shifting coastal dunes; CSCA; MEI030677-8, 030680 • 1 female; Tel Aviv District, Holon, nr. Tel Aviv; [31.9999, 34.7793]; 6 Apr 1968; S. Bleszynski leg.; CNC; MEI079732 . Tunisia • 1 female; Kebili Governorate [Qibili], Jebil National Park ; [32.9777, 9.0425]; 5-13 Oct 2010; H. Pohl leg.; sand dunes; CSCA . Morocco • 1 female; Agadir-ida Ou Tanane Province , 10 km S Agadir, Tifnit ; [30.1972, -9.6383]; 15.IV.2015; Schmid-Egger leg., 43 m; CSCA .

Diagnosis.

Male frons lacking dark maculae (small light brown suffused areas present); male frons slightly narrower than ocellar tubercle at narrowest point; female frontal maculae without erect macrosetae; cell m3 closed; all macrosetae white; dorsocentral macrosetae absent; palpi slender.

Redescription.

Body length: 5.5-7.0 mm (male), 7.5-11.0 mm (female). Head. Frons profile flat, pubescence grey, silver ventrally and on face, pair of suffused brown marks dorsally along eye margin (male) or matte-black maculae (female), lacking setae on frons; male frons width at narrowest point slightly wider than anterior ocellus; female frons broad with inner margins of eyes sub-parallel; white postocular setae arranged in single row immediately laterad of ocellar tubercle, barely discernible from pale setae; male occiput relatively convex, pubescence silver admixed with white, scale-like setae abundant medially; antennal scape length equal to flagellum, brown (male) or dark yellow (female), overlain with grey pubescence admixed with numerous large pale macrosetae; flagellum brown; genal setae white, palpi slender, setae white. Thorax. Scutum grey, with erect filiform setae admixed with adpressed, white, scale-like setae, denser anteriorly; thoracic macrosetae white to yellow; scutellum concolourous with scutum; pleuron with dense silver-grey pubescence admixed with extensive semi-erect, white, scale-like setae; coxae dark, overlain with silver-grey pubescence, setae white, macrosetae few in number and pale; femora uniform yellow (female) or dark brown (male), dense covering of white, scale-like adpressed setae, macrosetae white; hind femur with 3-4 fine anteroventral macrosetae spaced along entire length; tibiae yellow, dark grey-brown apically (male) or dark yellow (female); tarsi dark yellow, brown apically in male; wing opaque white, brown along veins (darker in female); cell m3 closed; venation yellow basally along major veins, darker distally; haltere stem orange-brown, knob yellow; scutal chaetotaxy: notopleural, 3; supra alar, 1; post alar, 1; dorsocentral, 0; scutellar, 2. Abdomen. Dark brown, yellow posteriorly on all tergites, pale filiform setae admixed with adpressed, white, scale-like setae (denser in male); terminalia dark yellow; female acanthophorite spines yellow. Male genitalia. Epandrium with extensive pale setae, narrowed posteriorly with posterolateral corners acute and divergent; sternite 8 quadrangular with strongly emarginate posterior margin, elongate pale setae on entire surface; gonocoxites with small ridge-like outer gonocoxal process; inner gonocoxal process narrow; gonostylus with angular ridges along outer surface; phallus with dorsal apodeme broader posteriorly with shoulder like ridges; ventral apodeme broad, triangular; distiphallus short, narrow.

Distribution.

Egypt, Israel, Mauritania, Morocco, Sudan, Tunisia.

Ecology.

Neotherevella macularis adults are found on vegetated sand dunes.

Conservation status.

Not threatened; a widely distributed species.

Comments.

Neotherevella macularis was originally described in the genus Thereva , based on a single female specimen from Abyssinia (Sudan), although listed as Egypt by Wiedemann (1828) and Kröber (1912d). Kröber (1912d) and Lyneborg (1976) redescribed this species, noting that, despite the poor condition of the type specimen, it retained the distinctive colouration and markings typical of the genus. The species was transferred to Neothereva (sensu Lyneborg, 1976) and subsequently to Neotherevella by Lyneborg (1978). Lyneborg (1976) redescribed it briefly and compared it with his newly-described N. arenaria from southern Africa, although surprisingly not with the geographically nearby N. citrina . At the time, the male of N. macularis was unknown, but Lyneborg (1976) assumed that it would certainly have the eyes well separated, a character which is indeed typical of N. citrina . As mentioned previously, in his revision of Neothereva , Lyneborg (1976) incorrectly designated T. citrina as the type species of the genus, something he subsequently corrected ( Lyneborg 1978) by describing Neotherevella and designating T. citrina as the type species. Lyneborg (1976) indicated his placement of T. macularis in Neothereva was novel, apparently being unaware that it had already been proposed by Kröber (1937). Moreover, his synonymy of N. angustifrons with N. macularis was also not novel, as Kröber (1937) had previously identified N. angustifrons as a synonym of N. macularis along with T. nuba Wiedemann, 1828 (the latter species is now placed in Irwiniella ). Indeed, Kröber (1924b, 1929) suggested that T. macularis and his own N. angustifrons might be synonymous, although Kröber (1924a) erroneously considered T. macularis as a junior synonym of N. angustifrons ; he later recognised this error and reversed the synonymy ( Kröber 1937) as T. macularis is the senior name and, thus, takes precedence.

On the status of three names in question (i.e. T. macularis , T. citrina and N. angustifrons ), T. citrina being a junior synonym of T. macularis is the only one that has not been previously proposed. The male is known for N. citrina and N. angustifrons , but not N. macularis , but comparison of types and a series of specimens (males and females) indicates that characters used previously to separate them (notably scutal colour and markings or frontal markings) tend to be highly variable or obscure. Moreover, the recorded distributions of all three overlap: N. citrina is recorded from Mauritania to Israel, N. angustifrons from Egypt and N. macularis from Sudan, Egypt and Mauritania.

Neotherevella macularis can be separated from all other species of Neotherevella by the male frons being only slightly wider than the anterior ocellus, wing cell m3 closed and by the shape of the male epandrium and phallus.

Figures

Figure 8. Neotherevella macularis (Wiedemann, 1828), female A oblique view B lateral view.

Figure 9. Neotherevella macularis (Wiedemann, 1828), male A oblique view B 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.