Megatrigon immaculatus, Doczkal & Radenković & Lyneborg & Pape, 2016

Doczkal, Dieter, Radenković, Snežana, Lyneborg, Leif & Pape, Thomas, 2016, Taxonomic revision of the Afrotropical genus Megatrigon Johnson, 1898 (Diptera: Syrphidae), European Journal of Taxonomy 238, pp. 1-36 : 26-27

publication ID	https://doi.org/ 10.5852/ejt.2016.238
DOI	https://doi.org/10.5281/zenodo.3854658
persistent identifier	https://treatment.plazi.org/id/03EA327E-FFF8-EC0D-FDCA-EB0AFC03FE69
treatment provided by	Valdenar
scientific name	Megatrigon immaculatus
status	sp. nov.

Treatment

Megatrigon immaculatus View in CoL sp. nov.

urn:lsid:zoobank.org:act:247A01B0-3787-429C-AD8E-0DAFFEADE8FC

Figs 1I View Fig , 2J View Fig , 3I View Fig , 7I View Fig , 10I View Fig , 11I View Fig , 12H View Fig , 16 View Fig

Diagnosis

Dark brown-black species with almost no markings and blue lustre, covered with short white hairs ( Fig. 1I View Fig ); 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 View Fig ); 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 View Fig ); 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 View Fig , 3I View Fig ). 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 View Fig ). Male genitalia in Figs 10I View Fig , 11I View Fig , 12H View Fig .

Distribution

Afrotropical – South Africa (Eastern and Western Cape) ( Fig. 16 View Fig ).