Megatrigon argentimaculatus, 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 : 20

publication ID	https://doi.org/ 10.5852/ejt.2016.238
publication LSID	lsid:zoobank.org:pub:36FC5EA6-E82D-4E21-9060-030CF13ED1B7
DOI	https://doi.org/10.5281/zenodo.3854668
persistent identifier	https://treatment.plazi.org/id/42BB0474-749D-4B47-BF20-C5C9F1C1B84C
taxon LSID	lsid:zoobank.org:act:42BB0474-749D-4B47-BF20-C5C9F1C1B84C
treatment provided by	Valdenar
scientific name	Megatrigon argentimaculatus
status	sp. nov.

Treatment

Megatrigon argentimaculatus View in CoL sp. nov.

urn:lsid:zoobank.org:act:42BB0474-749D-4B47-BF20-C5C9F1C1B84C

Figs 1C View Fig , 2C View Fig , 3C View Fig , 7C View Fig , 10C View Fig , 11C View Fig , 12C View Fig , 15 View Fig

Diagnosis

Microtrichia pattern of head ( Fig. 2C View Fig ): Frons shiny anteriorly, microtrichiose posteriorly; between frons and vertex bare transversal line; vertex covered with microtrichia, except ocellar triangle, small central area behind ocellar triangle, short longitudinal line medio-posteriorly and head edge; microtrichia of post-ocular orbit exceeded post-ocular ridge and joined with postocellar microtrichia.

Etymology

The species epithet, which is formed as an adjective, is derived from the Latin words argentum (= silver) and macula (= spot), alluding to the large silver spots on abdominal tergites 2+3.

Type material

Holotype

SOUTH AFRICA: ♁, Eastern Cape, Albany Dist., Resolution , 23 Apr. 1928, A. Walton leg. ( NMSA).

Description

LENGTH. Body 8.0 mm, wing 5.5 mm.

HEAD ( Figs 2C View Fig , 3C View Fig ). Microtrichiose stripes on face along eye margin wide and long, extended till tentorial pit and joined with microtrichia below antenna by oblique microtrichiose stripe; distance between eyes a little larger than in M. argenteus comb. nov., 0.17 × width of head; ocellar triangle isosceles, without median longitudinal groove; colour of postpedicel ( Fig. 3C View Fig ) dictinctly darker than pedicel.

THORAX. Mesoscutum with two, wide, lateral microtrichiose stripes and two weak submedian microtrichiose stripes starting as triangular markings and ending as small spots at the level of transverse suture; supra-alar setae yellow; median about 0.50 of width of mediotergite covered by microtrichia.

WING. Membrane not infuscated, with yellow veins and microtrichia; cell br above vena spuria completely covered with microtrichia; costagium with yellow setae.

LEGS. Dark submedian ring on pro- and mesotibia weak and visible only ventrally, microtrichia on metatibia distinct in proximal half, dorsally; all tarsi yellow-orange, without shading; all setae of legs light yellow; tarsomere 1 of pro- and metaleg not swollen like in M. argenteus comb. nov.; tarsomere 1 of protarsus anterodorsally without a line of minute black spinules between the yellow trichia.

ABDOMEN ( Figs 1 View Fig , 7C View Fig ). Tergites light yellow setose; tergites 2+3 with very large silver spots, covering most of the tergite’s width except for a narrow brown goblet–shaped median part; distance between silver spots on tergite 2 smaller, 0.19 × width of tergite; spots on tergite 3 not tapering towards the middle of tergite, but being more rounded; silver spots on tergites 2+3 covered with relatively long, dense, adpressed, yellow setae except antero-lateral corner; tergite 4 with two small indistinct microtrichiose spots near to anterior margin. Male genitalia in Figs 10C View Fig , 11C View Fig , 12C View Fig .

Distribution

Afrotropical – South Africa (Eastern Cape) ( Fig. 15 View Fig ).