Tethina yemenensis Munari, 2007

Munari, Lorenzo, 2016, The Canacidae of the Arabian Peninsula (Diptera: Brachycera: Carnoidea), Zootaxa 4092 (4), pp. 489-517 : 509

Tethina yemenensis Munari, 2007

(figs. 41─43)

Tethina yemenensis Munari, 2007: 112 [ Yemen. Al Kowd, light trap; HT ♂, NMWC]

.

Distribution. Afrotropical: Yemen.

Diagnosis. Body length 1.5‒2.4 mm; pale yellow to whitish species with greyish to pale brownish mesonotum; scutellum with apical, dark brown discal spot (fig. 41); setal vestiture golden yellow; wing with pale yellow membrane and veins, except for the dark brown vein CuA1. Head subquadrate, slightly higher than long, entirely whitish, with pale yellow frons; setulation of head extremely thin, pale yellow; antenna yellow, arista distinctly infuscated on its distal half; ventral face not or moderately protrudent; eye oblique, markedly oblong, its longest diameter 2.5 times as long as the height of the gena; gena evenly microtomentose; labella stumpy, distinctly shorter than the length of the buccal cavity; 2-3 irregular rows of acrostichal setulae on the anterior half of the scutum; prescutellar acrostichals lacking; both proepisternal and proepimeral setae present; all legs, including coxae, pale yellow, with apical tarsomere of mid and hind legs infuscated; crossveins without white halo; crossvein dm-cu a little shorter than half of the last section of CuA1; abdomen predominantly whitish, with third tergite showing brown spot laterally and fourth tergite extensively brown; male terminalia with epandrium noticeably large and globoid (fig. 43), bearing few sparse short setae on the posterodorsal surface and one longer, lateral seta subapically; cercus with apex slightly thickened in posterior view; surstylus large, elongated, with antero-proximal corner bearing long setae (lateral view, fig. 42), and with a scarcely developed, spinulose lobe on its mesal surface (posterior view, fig. 43).

Remarks. In addition to the genitalic features, this species is characterised mainly by its pale yellow to whitish body hue, including the entirely whitish head, with pale yellow frons and remarkably pale and thin setulation. The prescutellar acrostichal setae are lacking. An additional distinctive character is found on the wing, which shows a distinctly dark brown vein CuA1. Furthermore, the male terminalia are characterised by an unusually large and globoid epandrium bearing few sparse short setae on its posterodorsal surface in addition to the usual longer lateral subapical seta.