Mesembrius senegalensis (Macquart, 1842) Figs 20, 40, 63, 78, 100, 121, 144, 161, 174, 181, 200, 222

Helophilus senegalensis Macquart, 1842: 121.

Tubifera senegalensis - Kertész (1910): 260.

Mesembrius senegalensis - Curran (1927): 65 - Curran (1939): 10 - Smith and Vockeroth (1980): 504.

Helophilus africanus Verrall, 1898: 416. syn. nov.

Tubifera africana - Kertész (1910): 249.

Helophilus (Mesembrius) africanus - Bezzi (1915): 97.

Mesembrius africanus - Smith and Vockeroth (1980): 504.

Differential diagnosis.

Mesembrius senegalensis males lack an apical pile brush on the profemur and have an unmodified metatibia. The proximal ventral part of the profemur lacks black pile and the metafemur is covered with long, thin yellow pile and has a band of very short, thicker, black pile on the posteroventral side and some scattered short black pile ventrally. The yellow-orange maculae on tergite II are very large and rectangular and the anterior and posterior black markings are narrow and perpendicular to the narrow medial black vitta. The male is distinguished from morphologically similar species in the shape of the maculae on tergite II which are rectangular (rounded to triangular in other species) and the band of short thick black pile on the posteroventral side of the metafemur (fewer in M. longipilosus sp. nov.; much denser and longer in M. copelandi sp. nov., M. minor and M. strigilatus). Apart from the shape of the maculae, it also differs from M. longipilosus sp. nov. with the absence of equally long black pile amongst the long yellow pile on the proximal ventral end of the metafemur (several in M. longipilosus sp. nov.). Females have a frons which is pale pilose on the ventral half. Tergite II has a pair of yellow maculae (fascia in M. capensis and spined morph of M. caffer). The black markings on the abdomen are strongly reduced because of the strong white pollinosity (clearly visible in all other species). The pro- and metafemur, as well as the pro- and metatibia are yellow-brown (largely dark brown to black in other species) and the metafemur has no ventral swelling in the middle (swelling present in M. minor).

Examined material.

Helophilus senegalensis Macquart: Lectotype (hereby designated), male, “SYNTYPE” " MNHN, Paris // ED6788" " 1 ♂ Helophilus // Helophilus senegalensis Macq // C.F. Kassebeer 1999" [MNHN]. Paralectotype, female, “SYNTYPE” " MNHN, Paris // ED6789" [MNHN] [the female is indicated as male on MNHN website] [a paralectotype is present at the MNHN, but could only be studied from the pictures on the website; see comments].

Helophilus africanus Verrall: Lectotype (hereby designated), male, "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 23.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 413." "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 23.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 416." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 413." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 416." "TYPE Dipt: 105 1/4 // Helophilus // Mesembrius africanus // Verrall // HOPE DEPT. OXFORD" "1899 // 7645" "RMCA PIC // 00012" “LECTOTYPUS” [OXUM] . Paralectotype, male, "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 23.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 413." "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 23.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 416." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 413." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 416." "TYPE Dipt: 105 3/4 // Helophilus // Mesembrius africanus // Verrall // HOPE DEPT. OXFORD" "1899 // 7646" "RMCA PIC // 00013" "PARA- // LECTOTYPUS " [OXUM] . Paralectotype, female, "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 24.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 413." "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 24.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 416." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 413." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 416." "TYPE Dipt: 105 4/4 // Helophilus // Mesembrius africanus // Verrall // HOPE DEPT. OXFORD" "1899 // 7650" "RMCA PIC // 00015" "PARA- // LECTOTYPUS " [OXUM] . Paralectotype, female, "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 23.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 413." "S.W. ARABIA // 19 m. fr. Aden, // Haithalhim. // Capt. Mar. 23.95 // & press. 1899 by // J.W. Yerbury. // Trans. Ent. Soc., // 1898, page 416." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 413." "TYPE. // G.H. VERRALL // Trans. Ent. Soc., // 1898, page 416." "TYPE Dipt: 105 5/4 // Helophilus // Mesembrius africanus // Verrall // HOPE DEPT. OXFORD" "1899 // 7648" "RMCA PIC // 00016" "PARA- // LECTOTYPUS " [OXUM] . Paralectotype, female, "Haithalhim // 23.3.95 // Col. Yerb. " "VC-TYPE 33 // Helophilus ♀ // Mesembrius africanus // Verrall " “Haithalhim” "PARA- // LECTOTYPUS " [OXUM] .

Other material

Benin • 1♂; Cotonou; Feb 2003; G. Goergen leg.; IITA • 2♀♀; Cotonou; 14 Jan 2013; K. Jordaens and G. Goergen leg.; KMMA • 1♂ 1♀; Cotonou; 28 Jan 2016; K. Jordaens and G. Goergen leg.; KMMA • 1♂; Togbin; Dec 2005; G. Goergen leg.; IITA . Chad • 1♀; Bebedja; date unknown; F.A. Brink and R.M. Brink-Moenen leg.; RMNH . Kenya • 2♂♂ 7♀♀; Jipe, Taita-Taveta; 27 Jan 2017; M. Reemer leg.; RMNH • 2♂♂ 2♀♀; Jipe; Taita-Taveta; 27 Jan 2017; X. Mengual leg.; ZFMK • 1♀; Nairobi, ICIPE campus; 6 May 2014; R. Copeland leg.; ICIPE • 1♂; Taita Hills; 2017; A. Ssymank leg.; ASPC • 1♀; Makindu; 5-7 Apr 1911; S.A. Neave leg.; NHMUK . Oman • 1♂; Dhofar, Ayun pools; 8 Oct 1977; K.M. Guichard leg.; NHMUK .

Re-description male

(Fig. 20). Body length: 12.0-13.8 mm. Wing length: 9.2-10.2 mm.

Head (Fig. 63). Eyes bare; slightly dichoptic, distance between eyes approx. 1/2 width of ocellus. Face yellow with dark medial vitta; yellow pilose; yellow pollinose. Vertical triangle with yellow pile and yellow pollinosity in lower half, black in upper half; distance between lateral ocellus and eye margin less than 1/2 width of ocellus. Occiput yellow; yellow pilose with interspersed short, black setulae; yellow and white pollinose. Frontal triangle yellow; yellow pilose; yellow pollinose. Frontal prominence shiny black; yellow pilose. Antenna black; antennal arista reddish-brown.

Thorax. Scutum black with three dorsal, well-demarcated yellow vittae which are connected anteriorly and posteriorly; with lateral, yellow vitta; pile rufous. Scutellum yellow-brown; yellow pilose.

Legs. All legs light- to dark brown. Proleg (Fig. 161) and mesoleg (Fig. 181): profemur without apical pile brush; yellow pilose, pile ventrally long in proximal half, shorter in distal half; with shorter black pile on distal half. Tibia yellow and black pilose. Tarsi black pilose dorsally, yellow pilose ventrally; with some thick black pile posterodorsally. Metaleg: Femur anteriorly and dorsally with long and posteriorly with shorter, yellow pile; ventral yellow pile scarce, except for a row of long, thin pale pile; with band of short black pile posteroventrally. Tibia unmodified; long yellow pilose; ventrally with much shorter and thicker black pile. Tarsi black pilose dorsally, yellow pilose ventrally.

Wing (Fig. 144). Entire wing uniformly dense microtrichose.

Abdomen (Fig. 100). Tergite II with a pair of very large, yellow to orange rectangular maculae; medial black markings very narrow and perpendicular to anterior and posterior narrow, black marking; posterior black marking with short, stiff black setulae which do not extend to the lateral tergite sides; white pollinose. Tergite III and IV with very large, yellow fascia; yellow pilose; with large medial black marking; with short black stiff setulae posterior to medial dark spot, these setulae not reaching the lateral tergite sides. Tergite III white pollinose in medial part. Tergite IV entirely white pollinose.

Genitalia (Fig. 222). Epandrium: Dorsal lobe of surstylus distally broadly rounded, with characteristic upwardly pointed projection; long pilose dorsally; with shorter, dense black pile ventrally and laterally. Ventral lobe of surstylus with a row of approx. 10 long black setulae.

Re-description female

(Fig. 40). Body length: 11.5-14.4 mm. Wing length: 8.3-10.4 mm. As male, except for the following character states: Eyes dichoptic (Fig. 78). Frons yellow pilose in ventral 2/3, black and yellow pilose on dorsal 1/3 (ocellar triangle and surrounding area); strongly yellow pollinose. Pile on legs shorter (Figs 174, 200). Abdomen as in Fig. 121.

Distribution.

Benin, Chad, Kenya, Oman and Yemen.

Comments.

Verrall (1898) already suggests that M. africanus could be conspecific to M. senegalensis (Macquart, 1842), but he did not study the type of the latter. We have studied the syntypes of both species and confirm Verrall’s suggestion that both species are conspecific and, therefore, we consider M. africanus (Verrall, 1898) a junior synonym of M. senegalensis (Macquart, 1842). A paralectotype of M. senegalensis (at the MNHN) is on loan and several requests to the borrower to return the specimen were left unanswered.