Extensive erect, white setae on head, body and legs; female frons wide, inner eye margins subparallel to slightly divergent; parafacial setae absent; hind coxal knob relatively minute or absent; elongate macrosetae on tibia and tarsi; series of anteroventral macrosetae on hind femur; wing opaque white with brown markings; male distiphallus narrow, short.

Small to medium-sized flies extensively covered with erect, elongate pile. Head length and height subequal; frons flat, grey pubescent with pair of large matte black pubescent spots in female (rarely in male); vertex sunken (especially in female); inner margins of female eyes subparallel; gena rounded; male frons width variable, contiguous below anterior ocellus to wider than ocellar tubercle; frons width strongly sexually dimorphic; parafacial without setae; face flat; occiput pubescence dull silver to grey-brown, postocular ridge and occiput in both sexes with macrosetae few in number, single row or irregularly arranged; antenna shorter than to subequal to head length, positioned on lower half of head and directed anteriorly; flagellum shape variable, cylindrical (slightly tapered distally), elliptical or conical, length shorter than or subequal to combined scape and pedicel length, style apical; scape short, less than 3× pedicel length, cylindrical, noticeably thicker than pedicel and base of flagellum; palpus slender or crassate, mouthparts short. Thorax with central depression of prosternum setose; cervical sclerite lacking macroseta; pleuron with silver pubescence admixed with erect, filiform and lanceolate setae; metanepisternum with postspiracular setae present; metakatepisternum setae absent; scutum covered with lanceolate and filiform adpressed setae, often of variable length and white; scutal chaetotaxy (pairs of macrosetae): notopleural, 3–5; supra alar, 1– 2; post alar, 1; dorsocentral 0–6; scutellar, 2; posterior surfaces of mid- and hind coxae setose, hind coxal knob absent or reduced in size; all legs approximately equal length; fore and mid-femoral anteroventral (av) macrosetae present or absent, hind femur with anteroventral (av) setae as series along segment, posteroventral (pv) macrosetae present or absent; femoral vestiture as filiform setae admixed with adpressed, lanceolate and scale-like setae; tibial macrosetae elongate; claws relatively small; wing cell m₃ open or closed; wing white opaque with variable mottled pattern; vein R₁ with setae absent (rarely single seta present); wing membrane densely covered with microtrichia. Abdomen shape relatively short or elongate, slightly narrowed along length. Male terminalia with gonocoxites separate medially, posteromedial margins proximal; inner gonocoxal process (igp) present, articulated; posterior outer gonocoxal process (ogp) barely evident; ventral lobe elongate, half the length of gonostylus; phallus with dorsal apodeme of parameral sheath broad, covering aedeagus dorsally or quadrangular, dorsal apodeme separate from gonocoxites, distiphallus narrow, short and directed ventrally, ventral apodeme as single lobe, narrow. Female terminalia with acanthophorite setae present as two sets (A1 and A2), A1 enlarged and elongate; sternite 8 emarginate posteromedially; tergite 8 elongate with anteromedial process; spermathecal sac as single round lobe, two round spermathecae.

Neotherevella arenaria (Lyneborg, 1976), N. kozlovi (Zaitzev, 1971a), N. londti sp. nov., N. macularis (Wiedemann, 1828), N. maroccanus sp. nov.

Neotherevella was described by Lyneborg (1978) as a clarification of the confused taxonomic concept of the genus Neothereva Kröber, 1912b, itself being a heterogeneous composite of species now placed in Neotherevella and Thereva — the latter of which Neothereva is arguably a synonym (see Lyneborg 1976, 1978). Kröber (1912b) described Neothereva with five Palaearctic species: N. nitidifrons Kröber, 1912b; N. angustifrons, 1912b; N. latifrons (Macquart, 1848); N. citrina (Becker, 1902) and N. frontata Kröber, 1912b. Lyneborg (1976) noted that the essential distinction between Thereva and Neothereva by Kröber (1912b) was that the male eyes are widely separated. Kröber (1929, 1932, 1937) subsequently identified multiple synonyms or novel combinations, as well as including Neothereva as a subgenus of Thereva (Kröber, 1932). In a catalogue of Palaearctic Therevidae, Kröber (1937) designated N. nitidifrons as the type species of Neothereva. In his revision of the Afrotropical Therevidae, Lyneborg (1976) overlooked this type species designation and incorrectly designated N. citrina (Becker, 1902) as the type species of the genus. Therein, T. frontata and T. nitidifrons were moved to Thereva, T. latifrons implied as a nomen dubium, while Neothereva was more narrowly circumscribed around N. citrina along with the newly-described N. arenaria. Lyneborg (1976) also synonymised N. angustifrons with N. citrina and Thereva macularis Wiedemann, 1828 was moved to Neothereva. Recognising his previously incorrect type species designation for Neothereva, Lyneborg (1978) synonymised Neothereva (sensu Kröber, 1937) with Thereva and transferred N. arenaria, N. citrina and N. macularis to a new genus Neotherevella (again based on the type species as T. citrina) along with a species described previously in Aristothereva (A. kozlovi Zaitzev, 1971a).

Neotherevella, Aristothereva and Acantothereva form a closely related group of specialised genera associated with sandy habitats, especially dunes, that is part of a larger clade also comprising the species-rich and widely distributed genera Irwiniella and Acrosathe (see Holston et al. 2007; Holston 2009; Winterton et al. 2016). Neotherevella is differentiated from other therevine genera by the presence of paired dark maculae on a wide female frons (also in the male of N. londti sp. nov.), parafacial setae absent (present in Acrosathe and Acantothereva, variable in Aristothereva) and a distiphallus that is narrow and curved ventrally (bulbous in Acantothereva; ornately spinose in Aristothereva). Other features of this genus variably shared with Acantothereva and Aristothereva include a wide, sunken vertex (especially in females), opaque white wings with dark maculation, reduced hind coxal knob, elongate tibial macrosetae and extensive white pile on the head and body frequently admixed with white scale-like setae. Paired matte-black pubescent maculae on the female frons are present in all species of Neotherevella, but are also found in some species of Acrosathe (for example, notably Acrosathe vialis (Osten Sacken, 1877), suggestive also of the close relationship of these genera.

Neotherevella is widely distributed throughout the Palaearctic Region and disparately in southern Africa. The most eastern species, N. kozlovi, is recorded from China and Uzbekistan. In the Mediterranean Region, N. macularis is widely distributed throughout northern Africa from Israel to Mauritania; the apparently closely related and distinctively coloured N. maroccanus sp. nov. is known only from Morocco.

Namibia • male; Erongo Region, Swakopmund; 26–30 Jan 1972; NHM.

Namibia • 8 males, 7 females; Erongo Region, Swakopmund, Swakop River mouth; [-22.6886, 14.5275]; 8 m alt.; 9 Feb 1974; M.E. & B.J. Irwin leg.; coastal and riverbed dunes; CSCA; MEI028397–400, 120720–23, 120760–1, 178074–8 • 3 males; Erongo Region, Swakopmund, Swakop River mouth; [-22.6925, 14.5269]; 03 Feb 2012; T. Dikow leg.; sandy river bed and vegetated dunes; USNM; USNMENT01576797–9 • 2 males, 1 female; Karas Region; Lüderitz District, Agate Beach, 10 km N Lüderitz; [-26.5949, 15.1792]; 3 m alt.; 18 Feb 1974; M.E. & B.J. Irwin leg.; low coastal vegetated dunes; CSCA; MEI120715, 178075–6.

Male frons lacking dark maculae; female frontal maculae with short pile of erect macrosetae; male eyes contiguous below ocellar tubercle; wing cell m₃ closed; all macrosetae black; single pair (sometimes two) of dorsocentral macrosetae; palpus slender.

Body length: 6.0–6.5 mm (male), 7.0–7.5 mm (female). Head. Frons profile flat, wholly pubescent; male frons narrower than anterior ocellus, but eyes not contiguous, female frons broad with eyes slightly narrowed dorsally; frontal pubescence silver with dark yellow suffusion, female with paired matte-black maculae admixed with short, erect, black setae; male frons with small patch of short setae above antenna, female sparse short setae, frontal setae admixed black and yellow; postocular setae black, arranged in single row immediately laterad of ocellar tubercle (male), additional setae irregularly arranged medially (female); occiput relatively flat, silver pubescence admixed with white, scale-like setae, more abundant medially; genal setae pale, palpus narrow, covered with pale setae; antennal scape shorter than flagellum, slightly thickened and cylindrical, brown, overlain with grey pubescence admixed with erect black setae of varying lengths; flagellum conical, brown with grey pubescence. Thorax. Scutum grey-tan with brown markings, short erect filiform setae admixed with adpressed white scale-like setae, denser anteriorly; macrosetae black; 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 with pale macrosetae admixed with erect white, scale-like setae; femora with dense covering of white, scale-like, adpressed setae (sparser in female); legs dark yellow, macrosetae black; hind femur with 3–4 anteroventral macrosetae distributed along distal half; tarsi dark yellow with apices brown; tibial and tarsal macrosetae elongate; wing white with irregular-sized brown maculae (darker in female), spur veins often present in maculae; cell m₃ closed; wing venation yellow basally along major veins, darker distally; haltere dark yellow; scutal chaetotaxy (macrosetae pairs): notopleural, 3; supra alar, 1–2; post alar, 1; dorsocentral, 1–2; scutellar, 2. Abdomen. Male base colour yellow, grey pubescent, filiform setae admixed with adpressed setae, very dense in male; terminalia dark yellow; female abdomen dark yellow; acanthophorite spines black. Male genitalia. Epandrium sub-quadrangular, posterolateral corners thickened, rounded; sternite 8 rounded posteriorly with thickened margin and short series of elongate, marginal macrosetae; gonocoxite with extensive pale setae, outer gonocoxal process relatively narrow, angular; gonocoxal apodeme absent; inner gonocoxal process rounded apically; gonostylus narrow; ventral lobe short, rounded; distiphallus narrow, gradually curved ventrally; ventral apodeme triangular.

Figure 1. 

Neotherevella arenaria (Lyneborg, 1976), female A oblique view B lateral view.

Figure 2. 

Neotherevella arenaria (Lyneborg, 1976), male A oblique view B lateral view.

Coastal Namibia.

Neotherevella arenaria sp. nov. adults are found in coastal dune systems associated with low vegetation (Fig. 3).

Figure 3. 

Vegetated sand dunes at the Swakop River mouth, Swakopmund (Namibia); habitat of Neotherevella arenaria (photo copyright: Torsten Dikow).

Unknown; this species is apparently locally abundant in relatively undisturbed habitats.

Neotherevella arenaria sp. nov. is closely related to N. londti sp. nov. and represents a species pair sharing characters not found in other Neotherevella species, including erect macrosetae on the frontal maculae, black thoracic macrosetae (pale in other species) and distinct dorsocentral macrosetae (absent or indistinct in other species). These two species are found in south-western Africa, relatively disparately distributed from other Neotherevella species, which are found throughout the southern Palaearctic Region.

Peoples Republic Of China • male; Inner Mongolia, Etsin Gol, North Alashan, Gobi; [41.8056, 100.9883]; 23 Jun 1926; P. Kozlov leg.; ZISP; N2236.

Peoples Republic Of China • 3 males, 6 females; Inner Mongolia, same data as holotype; [41.8056, 100.9883]; 14–15 Mar 1908, 23 Jun 1926; P. Kozlov leg.; ZISP, CSCA. Uzbekistan • 1 female; Xorazm Region, Khiva; [41.3847, 60.3655]; 20 Apr 1927; L. Zimin leg.; ZISP.

Male frons lacking dark maculae, wider than ocellar tubercle at narrowest point; female frontal maculae without erect macrosetae; scape macrosetae white to yellow; palpus narrow; wing cell m₃ open; all macrosetae yellow-white; dorsocentral macrosetae absent.

Body length: 8.0 mm (male), 10.5 mm (female). Head. Frons profile flat to slightly rounded (female), male frons width at narrowest point slightly wider than ocellar tubercle, female frons wide, inner eye margins subparallel; pubescence greyish-silver, paired matte-black pubescent maculae present (female), male frons with setae absent, female frons with patch of pale setae beside and slightly below antennal base; postocular setae white, arranged in single row, occiput relatively convex, pubescence grey admixed with white, scale-like setae, abundant medially; genal setae pale; palpus narrow, with white setae; antennal scape bulbous, equal length to flagellum, brown, overlain with grey pubescence (male) or dark yellow-orange, overlain with grey pubescence (female), numerous large white-yellow setae; flagellum brown. Thorax. Scutum grey pubescent, erect, filiform setae admixed with adpressed, white, scale-like setae, denser anteriorly; thoracic macrosetae yellow; scutellum concolourous with scutum; pleuron with dense silver-grey pubescence admixed with extensive semi-erect, white, scale-like setae; coxae yellow, overlain with silver-grey pubescence, macrosetae few in number, setae white; femora uniform yellow (female) or dark grey-brown with apices yellow (male), dense covering of white, scale-like adpressed setae, macrosetae white, hind femur with 3–4 anteroventral macrosetae in distal half; tibiae and tarsi dark yellow, macrosetae elongate, white; wing opaque white, brown along veins; cell m₃ open; venation yellow basally along major veins, darker distally; haltere dark yellow; scutal chaetotaxy: notopleural, 5; supra alar, 1; post alar, 2; dorsocentral, 0; scutellar, 2. Abdomen. Male base colour grey pubescent with extensive long, pale filiform setae admixed with adpressed setae; terminalia dark yellow; female abdomen brown, tergites yellow posteriorly and laterally; acanthophorite spines yellow. Male genitalia. Epandrium ovoid, brown anteromedially, covered with pale setae, corners pointed posterolaterally; sternite 8 narrowed posteriorly, emarginate apically with elongate setae in posterior half; gonocoxites with dense white setae, outer gonocoxal process reduced to small ridge, inner gonocoxal process narrowed apically, gonostylus truncated apically, angular ridge on outer surface, ventral lobe relatively large, rounded; gonocoxal apodeme small; phallus with broad dorsal apodeme of parameral sheath, ventral apodeme triangular, distiphallus broad and curved ventrally.

Figure 4. 

Neotherevella kozlovi (Zaitzev, 1971) A female, lateral view B male, oblique view.

China (Inner Mongolia), Uzbekistan.

Neotherevella kozlovi adults are found in sand dunes habitats.

Not threatened; apparently widely distributed in relatively undisturbed areas.

Neotherevella kozlovi was originally described in Aristothereva by Zaitzev (1971a) and later transferred to Neotherevella by Lyneborg (1978). The presence of distinctive frontal maculae of the female frons supports this combination. This species is distinct from other Neotherevella species by the shape of the frons in both sexes and yellow scape macrosetae.

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.

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.

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.

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.

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.

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

South-western South Africa.

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

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.

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.

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.

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.

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.

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.

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.

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

Neotherevella macularis adults are found on vegetated sand dunes.

Not threatened; a widely distributed species.

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.

Morocco • male; Drâa-Tafilalet Region, Merzouga, 45 km S Erfoud; [31.0847, -4.0055]; 19 Nov 1989; M.E. Irwin leg.; sieved from dune sand beneath vegetation, pupated 21 Oct 1990, eclosed 8 Nov 1990; [pupal case attached to pin]; CSCA; MEI120637.

Male eyes contiguous below ocellar tubercle, male frons lacking dark maculae; wing cell m₃ closed; all macrosetae white; dorsocentral macrosetae absent; palpi slender.

Body length: 7.5 mm (male). Head. Male frons flat in profile, pubescence grey with orange suffusion, setae absent, eyes contiguous below ocellar tubercle; postocular ridge with white macrosetae arranged in single row immediately laterad of ocellar tubercle; male occiput relatively concave, pubescence grey with abundant yellow adpressed scale-like setae over occiput; antennal scape shorter than flagellum, slightly thickened, cylindrical, brown with grey pubescence admixed with numerous large, pale setae; flagellum brown, elongate cylindrical, pale setae basally; genal setae pale, palpi narrow with pale setae. Thorax. Scutal vestiture with yellow, adpressed, scale-like setae abundant, denser laterally and anteriorly; thoracic macrosetae yellow; scutellum similar to scutum; pleuron dark with sparse grey pubescence admixed with extensive semi-erect, white, scale-like setae, yellow on dorsal part on anepisternum; coxae yellow, overlain with silver-grey pubescence, setae white, coxal macrosetae few in number, white; femora orange, dense covering of adpressed, white, scale-like setae, macrosetae white, hind femur with 1–2 subapical anteroventral macrosetae; tibiae dark yellow; tarsi dark yellow with apices brown; wing opaque white, brown along veins; cell m₃ closed; venation yellow basally along major veins, darker distally; haltere dark yellow; scutal chaetotaxy: notopleural, 3; supra alar, 1; post alar, 1; dorsocentral, 0; scutellar, 2. Abdomen. Male abdomen dark yellow, extensive long, setae, yellow dorsally, white laterally and ventrally; terminalia dark yellow. Male genitalia. Not dissected. Externally, extensive long pale setae; gonocoxite with ridge-like outer gonocoxal process, tuft of elongate setae along ventral part of outer gonocoxal process; inner gonocoxal process narrow, spatulate apically. Female unknown.

Figure 10. 

Neotherevella maroccanus sp. nov., male A oblique view B lateral view.

Figure 11. 

Neotherevella species, head, frontal view A Neotherevella kozlovi (Zaitzev, 1971a), 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.

The species epithet is the adjective latinised version of Morocco.

Morocco.

Typical of many Therevidae, especially dune-associated species, N. maroccanus sp. nov. larvae are found around the bases of plants in dune vegetation, where the larvae predate on soil arthropods amongst the plant roots.

Undetermined; this species is only known from a single specimen from the Erg Chebbi sand dunes, which is a popular tourist destination.

Neotherevella maroccanus sp. nov. is a delicate, distinctively coloured species with an extensive covering of yellow and white pile. It appears closely related to N. macularis, sharing features such as a narrow male frons and wing cell m₃ closed. This species is known only from a single male specimen reared from a larva.

Figure 12. 

Neotherevella species, male epandrium and sternite 8 A, B Neotherevella arenaria (Lyneborg, 1976) C, D Neotherevella kozlovi (Zaitzev, 1971a) 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.