Megatrigon immaculatus Doczkal & Radenković & Lyneborg & Pape 2016, sp. nov.
Creators: name: Doczkal, Dieter
name: Radenković, Snežana
name: Lyneborg, Leif
name: Pape, Thomas
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Megatrigon
Megatrigon immaculatus

description: Megatrigon immaculatus sp. nov.
urn:lsid:zoobank.org:act: 247A01B0-3787-429C-AD8E-0DAFFEADE8FC
Figs 1I, 2J, 3I, 7I, 10I, 11I, 12H, 16
Diagnosis
Dark brown-black species with almost no markings and blue lustre, covered with short white hairs (Fig. 1I); face shiny, apart from white microtrichiose area below antennae, only traces of usual microtrichia pattern present; frons and vertex shiny without microtrichia, both inflated and without border between them, cuticle smooth without indistinct alveoli (Fig. 2J); tergites dark brown without any markings (except in a female tentatively assigned to this species with three pairs of weak, white, oblique microtrichiose fasciae on tergites 2–4) covered with white setae (Fig. 7I); tergite 4 with two small depressions on posterior half.
Etymology
The species epithet, which is formed as an adjective, is derived from the Latin negation prefix in - (= “not”; here in the assimilated form im -), and macula (= spot), alluding to the lack of spots or other distinct markings on the abdominal tergites.
Type material
Holotype SOUTH AFRICA: ♂, Eastern Cape, Queenstown, 28 Aug. 1962, A. Busse leg. (AMGS).
Additional material
SOUTH AFRICA: 1 ♂ 1 ♀, Western Cape, Uniondale District, Bo Kouga, Mar. 1954, museum staff leg. (SAMC). These specimens are not designated as paratypes, as they differ in small details from the type of M. immaculatus sp. nov. and for that reason may not be conspecific. More material is needed to explore the significance of the observed differences.
Description
LENGTH. Body 8.0 mm, wing 5.5 mm.
HEAD (Figs 2J, 3I). Distance between eyes larger than in M. argenteus comb. nov., 0.23 × width of head; postocular orbit slightly wider, the width of postocular orbit dorsally 0.11 × as wide as head; ocellar triangle equilateral, without median longitudinal groove.
THORAX. Mesoscutum with lateral microtrichiose stripes on notopleuron shifted medially (can be reduced), submedian stripes ended at the level of transverse suture; bare area on katepisternum and anterior anepimeron are larger than usual.
LEGS. Almost completely dark (pro- and mesotarsus slightly darkened dorsally) except pale ends of pro- and mesofemur and tibia and ventral surface of tarsi; legs entirely white setose; metafemur with blue-violet lustre anterodorsally.
WING. Membrane less infuscated than in M. argenteus comb. nov.; costagium with yellow setae; capitulum brown.
ABDOMEN (Fig. 7I). Male genitalia in Figs 10I, 11I, 12H.
Distribution
Afrotropical – South Africa (Eastern and Western Cape) (Fig. 16).
description: Published as part of Doczkal, Dieter, Radenković, Snežana, Lyneborg, Leif & Pape, Thomas, 2016, Taxonomic revision of the Afrotropical genus Megatrigon Johnson, 1898 (Diptera: Syrphidae), pp. 1-36 in European Journal of Taxonomy 238 on pages 26-27, DOI: 10.5852/ejt.2016.238, http://zenodo.org/record/3849874