Mallota meromacrimima Hull 1941
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 meromacrimima

description: Mallota meromacrimima Hull, 1941
Figs 2, 12, 26, 38, 48
Mallota meromacrimima Hull, 1941: 328.
Differential diagnosis
One of the two Madagascan species. It can be differentiated from the other Madagascan species (M. hirsuta) by the yellow face (darker orange in hirsuta), the posterior anepisternum with pale yellow pile (yellow-orange in hirsuta), the more reddish abdominal terga, and the presence of narrow interrupted fasciae of white pollinosity along the anterior margin of terga 3 and 4 (absent in hirsuta) but see comments below. Both can be differentiated from the only other Afrotropical species with bare eyes (M. aperta) by the absence of a distinct medial dark brown macula in the wing (present in aperta), and the unmarginated rounded scutellum (distinctly marginated in aperta).
Type material
Holotype
MADAGASCAR • ♂; Fianarantsoa Dist., Fanovana, Oriental Forest; Jan.–May 1937; C. Lamberton leg.; ANSP, ANSP ENT 142916 (6592).
Allotype
MADAGASCAR • ♀; same data as for holotype; ANSP, ANSP ENT 142917.
Description
Body length: 10.5–17.0 mm. Wing length: 10.5–12.5 mm.
Male
HEAD (Fig. 12). Eye bare; holoptic, eye contiguity for distance equal to ocellar triangle, ommatidia equal in size. Frons strongly protruding, in lateral view beyond facial tubercle; ground colour yellow; with medium long to long pale yellow pile; anterior of ocellar triangle black medium long pile. Ocellar triangle black; medium long black pilose. Face ground colour yellow, genae black; with whitish pollinosity, facial tubercle and medial part ventral of tubercle non-pollinose; with dispersed long yellow pile along dorsolateral margins, otherwise bare; facial tubercle distinctly pronounced. Antennal segments orange; arista bare, orange at base, darker distally; postpedicel wider than long.
THORAX (Fig. 2). Scutum subshining black; anteriorly, posteriorly and along transverse suture with grey pollinosity; anterior third with medium long to short yellow pile intermixed with shorter black pile, black pile predominant in central part; posterior two-thirds with short black pile, along posterior margin with few pale yellow hairs, postalar callus with longer yellow pile. Scutellum yellow to dark yellow, anterior margin narrowly darker; with long pale yellow pile; unmarginated. Pleura ground colour black; posterior anepisternum with long and dense pale yellow pile, katepisternum with dispersed long pale yellow pile, anterior and dorsomedial parts anepimeron with dispersed long black pile; otherwise pleura bare.
LEGS. Femora all thickened, black; with short dense black pile except ventrally where long black pile, sometimes intermixed with few pale yellow hairs; profemur posteriorly at base with longer pale yellow pile; mesofemur posteriorly along basal two-thirds with longer pale yellow pile continued distally by longer black pile; metafemur (Fig. 26) anterodorsally along basal two-thirds with row of longer pale yellow pile. Tibia and tarsal segments orange to red-brown; with short whitish pile.
WING (Fig. 38). Slightly fumose, more so along anterior margin, widening distally; most areas microtrichose. Stigmal cross-vein present between distal end of vein Sc and middle of vein R 1. Vein R 4+5 sinuate, without appendix.
ABDOMEN (Fig. 48). Mainly dark reddish brown, along anterior margin of tergum 2 black; with short black pile except tergum 1 with longer yellow-orange pilosity and white pollinosity; tergum 2 along anterolateral margins with longer yellow-orange pile; anterior margin of terga 3 and 4 with narrow fascia of white pollinosity, interrupted medially, and short whitish pile, anterolateral slightly widening; other terga laterally with longer whitish pile. Sterna black to red-brown; sterna 1–3 with very long, dispersed whitish pile intermixed with few shorter black pile, sterna 4–5 with dispersed black pile.
Female
As male except eyes dichoptic, frons yellow, in dorsal half medially slightly darker; with medium long to long pale yellow pile. Thorax, along posterior margin of scutum with pale yellow pile. Femora ventrally without long dense pilosity; only metafemur with dispersed black pile. Metafemur only thickened. Wing, fumose area along anterior margin less pronounced. Abdominal terga more orange-red.
Distribution
Madagascar.
Comments
Both species (M. hirsuta and M. meromacrimima) are similar in most respects especially when comparing the female holotype of M. hirsuta with the female allotype of M. meromacrimima. The main difference is the colouration of abdominal terga, the presence of distinct narrow fasciae of white pollinosity along the anterior margin of terga 3 and 4 in meromacrimima (see Fig. 48) and the pilosity on the scutum. However, abdominal tergal colouration has been shown to be very variable in some eristaline genera; for example, see revisions of Senaspis (De Meyer et al. 2020b) and Mesembrius Rondani, 1857 (Jordaens et al. 2021). The poor condition of the sole specimen of M. hirsuta makes comparison between both with regard to scutal and abdominal character states difficult. One paratype (not studied) of M. meromacrimima is collected at the same spot as the holotype of M. hirsuta. The type locality for M. meromacrimima is about 30 km east of the one for M. hirsuta. It is likely that both are actually varied representatives of the same species and the late F.C. Thompson already indicated this as such in the Systema Dipterorum website (http://www.diptera.org/), but the proposed synonymy was not officially published. However, because of the limited material available which does not allow a detailed investigation of the intra-specific variability and lacking molecular data, we do not propose a synonymy here. No DNA barcodes were obtained.
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 252-253, DOI: 10.5852/ejt.2024.958.2675, http://zenodo.org/record/13914492