Mallota extrema
Creators: name: Meyer, Marc De
name: Goergen, Georg
name: Midgley, John
name: Jordaens, Kurt
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Mallota
Mallota extrema

description: Mallota extrema (Loew, 1858)
Figs 8, 18, 32, 44, 54
Helophilus extremus Loew, 1858: 380.
Helophilus extremus – Loew 1860: 387.
Differential diagnosis
This species belongs to a group of three species that are characterized by the combination of the following character states: dispersed short pile on the eyes, holoptic eyes in the male, the metafemur only moderately thickened (as in M. aenigma), and ventral pile of metatibia longer (at least half as long as width). Mallota extrema can be differentiated from M. stipulata sp. nov. by the more pronounced facial tubercle (hardly present in M. stipulata), and the long frontal and ocellar pile (short in M. stipulata). It is almost identical to M. wyatti sp. nov. The main diagnostic character to differentiate it from M. wyatti is the colouration of abdominal tergum 2: with lateral triangular maculae in M. extrema, the posterior margin (almost) reaching the posterodorsal corner of the tergum; occasionally the triangular maculae are extended, touching medially and forming a complete fascia occupying more than half of the entire length of the tergum (in M. wyatti the colouration is limited to the anterodorsal corner, posteriorly never reaching beyond half of the length of the tergum). In addition, the metafemur in M. extrema is more distinctly coloured orange in the basal third (more obscured in M. wyatti) and the abdominal sterna 1–3 are partially yellow-orange coloured in M. extrema (completely black-brown to black in M. wyatti).
Type material
Lectotype
SOUTH AFRICA • ♀; “Caffraria” [unknown locality]; Wahlberg leg.; NRMS, NHRS-GULI 000102664. This specimen is hereby designated as lectotype.
Other material examined
MOZAMBIQUE • 1 ♀; Manica-Sofala, Villa Paiva d’Andrada; Sep. 1957; Stuckenberg leg.; NMSA, NMSA DIP 14086.
REPUBLIC OF THE CONGO (Congo-Brazzaville) • 1 ♀; Nouabale-Ndoki National Park, Mbeli Camp; 3–10 Oct. 2022; V. Dérozier, B. Fouka, A.H. Kirk-Spriggs and H. Takano leg.; carrion bait; ANHRT, ANHRTUK00278678 • 1 ♀; same data as for preceding; 14–20 Feb. 2023; N. Bakala, V. Dérozier, A. Kirk-Spriggs and G. Laszlo leg.; carrion bait; ANHRT, ANHRTUK00282318.
SOUTH AFRICA – KwaZulu-Natal • 1 ♀; ‘Stella B’ [= Stella Bush]; Jan. 1916; Marley leg.; NMSA, NMSA DIP 54536 • 1 ♂; Greater St Lucia Wetland Park; 9 Mar. 2004; J.G.H. Londt leg.; NMSA, NMSA DIP 65199 • 1 ♂; iSimangaliso wetland park; 12 Oct. 2021; Bellingan, Jordaens and Midgley leg.; NMSA, NMSA DIP 211609 • 2 ♂♂, 1 ♀; same data as for preceding; 14 Oct. 2021; NMSA, NMSA DIP 211699, NMSA DIP 211675, NMSA DIP 211677 • 2 ♂♂; same data as for preceding; 16 Oct. 2021; RMCA, RMCA ENT 000043830, RMCA ENT 000043831 • 1 ♀; Mtunzini; 27 Feb. 2021; T. Bellingan leg.; NMSA, NMSA DIP 208712 • 1 ♂, 1 ♀; same data as for preceding; 8 Oct. 2021; Bellingan, Jordaens and Midgley leg.; NMSA, NMSA DIP 193462, NMSA DIP 193456 • 1 ♂; same data as for preceding; RMCA, RMCA ENT 000044357 • 1 ♂; Saint Lucia, below Ingwenya Lodge; 12 Oct. 2021; Bellingan, Jordaens and Midgley leg.; RMCA, RMCA ENT 000044384 • 1 ♀; Umlalazi Nature Reserve; 2–10 Oct. 1982; J.G.H. Londt leg.; NMSA, NMSA DIP 43001. – Limpopo • 1 ♀; Transvaal, Zoutpansberg Range, Entabeni For. Station, Vera Kop Forest; 15 Jan. 1974; NMSA, NMSA DIP 63679.
TOGO • 1 ♂; Kloto; G. Goergen leg.; Feb. 2018; RMCA, RMCA AB72067308 • 1 ♂; same data as for preceding; Dec. 2021; RMCA, RMCA AB72067309.
Description
Body length: 11.5–15.0 mm. Wing length: 9.0– 10.5 mm.
Male
HEAD (Fig. 18). Eye with short and dispersed silvery pile; holoptic, eye contiguity for distance at least equal to length of ocellar triangle, ommatidia equal in size. Frons protruding, in lateral view equal or beyond facial tubercle; ground colour black, dorsal of antennae shining, otherwise light brown pollinosity, along eye margins more greyish; with long intermixed black and whitish pile, along lateral margins paler coloured, medially darker. Ocellar triangle black; short to medium long black pilose. Face ground colour black, sometimes more yellow laterally; with grey pollinosity, more densely so along eye margins, facial tubercle and ventrally of antennae non-pollinose; with dispersed long pale yellow pile along dorsolateral margins, otherwise bare; facial tubercle weakly pronounced. Clypeus smooth, without tuft of pile. Antennal segments black-brown to black; arista bare, black-brown; postpedicel longer than wide.
THORAX (Fig. 8). Scutum subshining black; with grey to brown pollinosity, with long pale yellow pile; medially fascia with darker brown pile. Scutellum yellow-brown, paler than scutum; with long pale yellow pile along apical margin; anteromedially darker brown pile. Pleura ground colour black; posterior anepisternum, katepisternum and anterior anepimeron with long pale brown pile, otherwise bare.
LEGS. Mainly black, anterior third to fourth of femora distinctly orange and apex narrowly pale orange, protibia at base pale orange, mesotibia pale area extending beyond middle of tibia. Proleg with intermixed black and pale yellow short pile, femur posteriorly long dense pile. Mesoleg predominantly short pale yellow pile, femur posteriorly long dense pile. Metaleg (Fig. 32), femur moderately thickened, with long dense pale yellow pile, except ventrally where predominantly shorter black pile; tibia curved, with conspicuous short black pile, ventrally longer pile, basally sometimes more pale yellow.
WING (Fig. 44). Largely hyaline; weak microtrichose, absent in parts. Distal end of vein Sc and middle of vein R 1 without distinct stigmal cross-vein but with darker brown macula between the veins. Vein R 4+5 sinuate, without appendix.
ABDOMEN (Fig. 54). Mainly shining black; tergum 1 orange and white pollinose; with long white pile. Tergum 2 with pair of orange-red triangular shaped maculae separated along medial line, maculae reaching along lateral margin till posterodorsal corner of tergum or almost so, occasionally maculae joined forming a full fascia that is occupying more than half of the entire length of the tergum; medial vitta of dense grey pollinosity along entire length except for anterior third, along posterior margin fascia of weaker pollinosity; predominantly short to medium long pale pile except along posterior margin where black; terga 3 and 4 distinctly grey pollinose along anterior margin, continued posteriorly along medial line, posterior margin fascia of weaker pollinosity; tergum 3 with short whitish pile except in posterior half to fourth where black; tergum 4 predominantly black pile. Sometimes orange maculae on abdominal terga more extensive, tergum 2 black areas restricted to anterior margin medially and posterior third, tergum 3 anterior fourth orange-red. Sterna black, sterna 1–3 partially yellow-orange; sterna 1–3 with very long, dispersed whitish pile; sterna 4–5 with dispersed black pile.
Female
As male except eyes dichoptic; frons subshining black dorsally of antennae, medially and along eye margins with distinct pollinosity, ventrally whitish and gradually darkening dorsally till brown-black anterior of ocellar triangle; pilosity black anterior of ocellar triangle. Scutum, maculae with black pilosity sometimes less distinct. Proleg predominantly pale yellow pilosity, tibiae basally usually more pale yellow pilosity.
Distribution
Congo (Brazzaville), Mozambique, South Africa, Togo. Records from Congo (D.R.) are based on misidentification (cf. Comments).
Comments
Johan August Wahlberg collected in South Africa and kept travel diaries, but the details in those diaries are not sufficient to assign a precise locality to the holotype. The type locality is likely to be in the KwaZulu-Natal province, but it could also be in the Free State, Gauteng, Mpumalanga or Northwest provinces.
Loew (1858) described Helophilus extremus based on material from South Africa. Curran (1927) places a single Afrotropical species under Mallota, i.e., M. pallidibasis, based on a series of specimens collected at Stanleyville [= Kisangani] in 1915. However, later on, Curran (1939b) considered those specimens to belong to M. extrema. As stated above, part of this material was re-examined and compared with the type of extrema, but they belong to M. hircus sp. nov. Curran (1939b) also considered as M. extrema the material listed by Bezzi (1915) as M. aenigma from Zimbabwe. However, our examination of the material at NHMUK confirmed the identification by Bezzi as M. aenigma.
Apart from the morphological differences, DNA barcodes also show substantial differentiation from M. wyatti (mean interspecific p-distance = 3.6%; range interspecific p-distances: 3.2–3.9%) and M. stipulata sp. nov. (mean interspecific p-distance: 3.9%; range interspecific p-distances: 3.6–4.1%) (Fig. 57; Table 2). The range of intraspecific p-distances in both species is much narrower (0–0.5%).
description: Published as part of Meyer, Marc De, Goergen, Georg, Midgley, John & Jordaens, Kurt, 2024, On the identity of the Afrotropical species of Mallota Meigen (Diptera: Syrphidae), pp. 242-290 in European Journal of Taxonomy 958 (1) on pages 268-270, DOI: 10.5852/ejt.2024.958.2675, http://zenodo.org/record/13914492