Mesembrius vockerothi Jordaens, Goergen & De Meyer, 2021

Jordaens, Kurt, Goergen, Georg, Skevington, Jeffrey H., Kelso, Scott & Meyer, Marc De, 2021, Revision of the Afrotropical species of the hover fly genus Mesembrius Rondani (Diptera, Syrphidae) using morphological and molecular data, ZooKeys 1046, pp. 1-141 : 1

publication ID	https://dx.doi.org/10.3897/zookeys.1046.57052
publication LSID	lsid:zoobank.org:pub:66E61C4E-FAFE-45DE-9145-DB38199BDEC3
persistent identifier	https://treatment.plazi.org/id/7EE04C53-0B7E-4D02-AB1D-0C71EABC9F7C
taxon LSID	lsid:zoobank.org:act:7EE04C53-0B7E-4D02-AB1D-0C71EABC9F7C
treatment provided by	ZooKeys by Pensoft
scientific name	Mesembrius vockerothi Jordaens, Goergen & De Meyer
status	sp. nov.

Treatment

Mesembrius vockerothi Jordaens, Goergen & De Meyer sp. nov. Figs 26 View Figures 25, 26 , 45 View Figure 45 , 69 View Figures 64–69 , 82 View Figures 79–82 , 106 View Figures 101–106 , 126 View Figures 124–126 , 150 View Figures 147–150 , 228 View Figures 217–228

Differential diagnosis.

Mesembrius vockerothi sp. nov. is the smallest of the Mesembrius species. Males lack an apical pile brush on the profemur, have an unmodified metatibia and are dichoptic and the face is markedly conical. It can be distinguished from the male of other species by its smaller size and the conical face. The yellow pile on the mesotarsomeres is inconspicuous (very prominent on all tarsomeres in M. capensis ) and the scutellum is yellow pilose with short black pile interspersed on its entire surface (yellow pilose only in both morphotypes of M. caffer , M. capensis , M. minor and M. senegalensis ; yellow pilose with black pile in posterior half in M. strigilatus ). Females have a frons which is pale pilose on the ventral half. It can be distinguished from the female of other species by its smaller size and the conical face. The pro- and metafemur are dark brown to black (yellow-brown in M. senegalensis ). Tergite II has a pair of yellow maculae (fascia in M. capensis and spined morph of M. caffer ) and the black posterior marking extends to the lateral margins (not so in M. minor ). The metafemur has no ventral swelling in the middle (present in M. minor ). The pro- and mesotarsi are uniformly dark brown (brown with a darker medial part in M. minor ). The posteroventral side of the metafemur has short black setae at distal 1/2 to 1/3 (only at distal 1/6 in the nominal morph of M. caffer and in M. strigilatus ).

Examined material.

Mesembrius vockerothi Jordaens , Goergen & De Meyer: Holotype, male," " UGANDA: // Kampala, // 12.xii.1934, // F.W. Edwards. //B.M. 1935-203." “HOLOTYPUS” " Mesembrius vockerothi // Jordaens & De Meyer 2019" " NHMUK 010369964" [NHMUK].

Paratypes: Democratic Republic of the Congo • 1♀; Kalembelembe, Baraka ; Jul 1918; R. Mayné leg.; RMNH • 1♀; North-Kivu, Beni à Lesse ; Jul 1911; Murtula leg.; KMMA . Kenya • 1♂; Jinja; Oct 1930; van Someren leg.; NHMUK • 1♀; Nyeri; Oct 1948; van Someren leg.; NHMUK . Uganda • 1♂ 1♀; Entebbe ; 17 Aug 1911; C.C. Gowdey leg.; NHMUK • 2♂♂; Entebbe ; 9 Nov 1971; H. Falke leg.; CNC • 1♂; Entebbe ; 5 Jan 1972; H. Falke leg.; CNC • 1♀; Kampala; 12-20 Mar 1918; C.C. Gowdey leg.; NHMUK • 3♂♂; Kampala; 12 Dec 1934; F.W. Edwards leg.; NHMUK • 1♂ 1♀; Namanue ; 13 Dec 1934; J. Ford leg.; NHMUK • 1♀; Tero Forest ; 26-30 Sep 1911; S.A. Neave leg.; NHMUK • 1♀; Unyoro District; C.H. Marshall leg.; NMSA • 1♀; Central Region, Wakiso District, Mabamba Swamp ; 16 Dec 2018; G. Ståhls leg.; MZH .

Other material

1♀ with locality and date unknown, D. Bruce leg. (NHMUK).

Description male

(Fig. 26 View Figures 25, 26 ). Body length: 11.0-13.2 mm. Wing length: 9.6-10.5 mm.

Head (Fig. 69 View Figures 64–69 ). Eyes dichoptic; distance between eyes approx. the width of anterior ocellus. Face conical; white with dark medial vitta; white pilose. Vertical triangle black; black pilose; yellow pollinose on ventral half. Distance between lateral ocellus and eye margin 1/2 width of ocellus. Occiput yellow; yellow pilose; yellow and white pollinose. Frontal triangle short; yellow-white; with long, black pile medially, yellow pilose on gena; yellow pollinose. Frontal prominence shiny dark brown to black. Antenna dark brown, antennal arista reddish-brown.

Thorax. Scutum black with, dorsally, a pair of well-demarcated white pollinose vittae which are connected posteriorly; lateral white pollinose vitta clear; yellow pilose. Scutellum yellow-brown; yellow pilose with shorter black pile interspersed on its entire surface.

Legs. All femora dark brown to black, except for extreme distal ends which are orange-brown; femora yellow to orange. Pro- and mesoleg: Femur with black pile on anterior and dorsal side and with longer yellow pile on posterior and posterodorsal sides. Tarsi yellow to orange. Metaleg: Femur with long and thin yellow pile; with black pile ventrally on distal half. Tibia with yellow and black pile, of which the yellow pile is longer on posterodorsal side. Metatibia unmodified. Metatarsi dark brown.

Wing (Fig. 150 View Figures 147–150 ). Entire wing uniformly very dense microtrichose.

Abdomen (Fig. 106 View Figures 101–106 ). Tergite II with a pair of very large yellow-orange, rounded maculae; black marking hourglass-shaped; posterior black marking equal in size to anterior black marking and with a medial white pollinose area; yellow pilose, but black pilose on posterior half of black marking. Tergite III with a pair of large yellow-orange maculae; with large black marking on posterior 2/3; yellow pilose on maculae, black pilose on black marking. Tergite IV black, with a pair of small yellow maculae in anterolateral corners; white pilose and strongly white pollinose on anterior and lateral parts; predominantly black pilose on black marking.

Genitalia (Fig. 228 View Figures 217–228 ). Epandrium: Dorsal lobe of surstylus distally broadly rounded, with characteristic large tooth-like projection; entirely pilose, except on tooth and at basis (stalk). Ventral lobe of surstylus with one large black setula in middle section and a row of 4-5 long black setulae.

Description female

(Fig. 45 View Figure 45 ). Body length: 14.0-15.1 mm. Wing length: 9.7-10.3 mm.

As male, except for the following character states: Eyes dichoptic (Fig. 82 View Figures 79–82 ). Frons white pilose, brown pilose on ocellar triangle and surrounding area; strongly white pollinose to just before ocellar triangle. Pile on legs shorter. Abdomen as in Fig. 126 View Figures 124–126 .

Distribution.

Democratic Republic of the Congo, Kenya and Uganda.

Comments.

This is a new species and the smallest in size of all Afrotropical Mesembrius hitherto known. It is the only Afrotropical Mesembrius species with a conical face.

Etymology.

Named in honour of the Dipterist Dick Vockeroth (1928-2012), who already indicated on the labels that some specimens from Uganda probably belonged to a new species. The specific epithet should be treated as a noun in the genitive case.