Megatrigon argentifrons sp. nov.

urn:lsid:zoobank.org:act: CCF520E8-EBFC-4269-956E-C5E31E92DF3F

Figs 1B, 2B, 3B, 6 A–B, 7B, 10B, 11B, 12B, 15

Diagnosis

Frons covered with very dense, long, silvery-white setae and microtrichia; on vertex microtrichia present anteriorly, along lateral sides of ocellar triangle and as small, but distinct postocellar spots (Fig. 2B).

Etymology

The species epithet, which should be treated as a noun in apposition, is derived from the Latin words argentum (= silver) and frons (= forehead), alluding to the dense, silvery microtrichiae that completely cover the frons.

Type material

Holotype SOUTH AFRICA: ♂, Western Cape, Stellenbosch, 8 Oct. 1926, Dr. H. Brauns leg. (RMNH).

Paratypes SOUTH AFRICA: 1 ♂, Western Cape, Uniondale Distr., Bo Kouga, Mar. 1954, museum staff leg. (SAMC); 1 ♂, KwaZulu-Natal, Bushmans Nek, 2929cc, slopes above hotel, 16 Nov. 1981, J.G.H. Londt leg. (NMSA).

Description

LENGTH. Body 7.0 mm, wing 5.0 mm.

HEAD (Figs 2B, 3B). Lateral margins of face more parallel while in M. argenteus comb. nov. slightly divergent; distance between eyes larger than in M. argenteus comb. nov., 0.19 × width of head; ocellar triangle eqilateral, without median longitudinal groove; on face microtrichiose stripes along eye margin wide at the level of antennae, but tapering and reduced at lower part, connected with microtrichia below antenna by tiny oblique microtrichiose line; median facial stripe well developed; microtrichia on postocular orbit do not exceed post-ocular ridge.

THORAX. Mesoscutum with two lateral microtrichiose stripes and two submedian microtrichiose stripes ending well behind level of transverse suture; supra-alar setae yellow; microtrichia on mediotergite medially occupied more than 0.5 of width.

WING. Membrane not infuscated, with light brown veins, microtrichia brown; cell br above vena spuria narrowly bare; costagium with yellow setae.

LEGS (Fig. 6 A–B). Setae on legs white without black ones; tarsomere 1 of metatarsus darkened dorsally, but without black setae intermingled with light ones.

ABDOMEN (Figs 1B, 7B). Tergites 2+3 with large silver spots, touching lateral and posterior margins of tergites, and almost anterior corner; tergite 3 is 2.2 × as wide as long (wider than in the closely related species M. natalensis sp. nov.); distance between silver spots on tergite 3 large, 0.22 × as wide as tergite (larger than in M. natalensis sp. nov.); tergites, especially black parts (median part of tergites 2+3 and whole tergite 4) covered with short, adpressed white-yellow setae (in M. natalensis sp. nov. longer and intensively yellow); silver spots on tergite 3 with reduced setae (contrary to M. natalensis sp. nov.); tergite 4 without microtrichiose spots. Male genitalia in Figs 10B, 11B, 12B.

Distribution

Afrotropical – South Africa (Western Cape and KwaZulu-Natal) (Fig. 15).