Silba upemba, Macgowan, Iain, 2015

Macgowan, Iain, 2015, A review of the Silba admirabilis McAlpine species group (Diptera: Lonchaeidae) with descriptions of thirteen new species from the Afrotropical region, Zootaxa 4032 (5), pp. 515-534 : 527

Silba upemba sp. nov.

Specimen in a moderate condition, glued to pin and slightly faded with age.

Description. Male: Head: Eyes bare. Frons 0.5x width of an eye, slightly brown with aging, dulled by microsculpture, frontal and interfrontal setulae less than 0.25x length of orbital seta, longer setulae present anteriorly above lunule. Orbital plates shining black, bare apart from the orbital seta.. Lunule with black ground colour, covered in silver pollinosity as to a lesser extent are parafacials. Anterior genal setulae rather short in a single row of 6 along mouth margin, these slightly separated from the other setulae. Antennae; 1st flagellomere black apart from an obscure brownish area at extreme medial base, length to depth ratio 3:1. Arista plumose, ratio of plumosity at maximum extent to depth of 1st flagellomere 1:1.

Thorax: mesonotum subshining blue black. Anepisternum 2 anterodorsal and 2 posterior setae. Katepisternum with 2 setae near the dorsal margin, posterior longer and stronger than anterior. Proepimeron and proepisternum each with 1 seta. Scutellum with disc heavily grey dusted, on margin between the lateral and apical setae with 4 setulae on each side, none between apical setae. Calypteres and fringes distinctly golden. Wings clear, wing length 3.6mm. Legs entirely black, basal tarsomeres yellow/brown, apical segments darkened.

Male terminalia ( Figs. 25–26 ): epandrium and associated structures of the standard S. admirabilis group type. Phallus: Basal plate, in ventral view widening only slightly from base, almost parallel sided but with a pair of lateral serrations at half way point, apically without any obvious incision, lateral margins more produced than the centre, the entire apical margin being covered in a loose row of spinules.

Type material. Holotype ♂. DEMOCRATIC REPUBLIC OF CONGO; P.N.U. (Park Nationale Upemba ), r.e. Lac Upemba , 585m, 1.ii.1949, Miss G.F. de Witte.

Only known from the Holotype, specimen in MRAC.

Etymology. The specific epithet refers to the Park Nationale Upemba where the holotype was captured.

Figures

FIGURES 25 – 26. Silba upemba sp. nov. 25. Phallus lateral view. 26. Same ventral view.