Silba zogbegani, Macgowan & Tschirnhaus, 2024

Macgowan, Iain & Tschirnhaus, Michael Von, 2024, Records of Lonchaeidae (Diptera, Cyclorrhapha) from Togo and other African countries, with descriptions of new species, Zootaxa 5514 (1), pp. 1-27 : 14

Silba zogbegani sp. nov. ( Figures 34–38 )

Description: Holotype male: Head: Eye with sparse, microscopic white hairs. Frons 0.5x width of an eye, parallel sided, dulled by microsculpture, frontal and interfrontal setulae short, approximately 0.2x length of orbital seta, longer setulae present on anterior margin adjacent to lunule. Orbital plate shining black, bare apart from the orbital seta. Lunule of faintly orange ground colour, lightly covered with a silver pollinosity which extends onto face and parafacial. Anterior genal setulae in a single row of 4–6 along mouth margin, the basal setula of this row long and strong, the strongest setula on the gena. Antenna entirely black, postpedicel length to depth ratio 2.7:1. Arista yellow basally, long plumose, ratio of plumosity at maximum extent to depth of postpedicel 1.8:1.

Thorax: Scutum sub-shining, slightly dusted, covered with setulae approximately 0.3x as long as orbital setae. Anepisternum slightly dusted, with a vertical row of three anterior and three posterior setae, a scattering of setulae between these two rows. Katepisternum slightly dusted with two equally strong setae near dorsal margin, the posterior slightly stronger than the anterior, numerous setulae on anterior part of this sclerite. One strong seta on proepisternum, a finer shorter seta on proepimeron. Scutellum grey dusted, margin with 3–4 setulae between lateral and apical setae, two between apical setae, all these setulae long, longer than the distance between the apical setae. Calypter white with a white fringe. Wing clear with yellow veins. Wing length 3.4mm. Legs entirely black.

Male terminalia: In lateral view; epandrium 1.5x higher than wide, with a short slightly hooked anterior projection, bearing a scattering of setae along posterior and ventral margins. Cercus relatively large, approximately 0.5x height of epandrium, sclerotised on ventral half which bears short setulae, dorsal half membranous. Posterior lobe of surstylus with prensisetae just visible below the cercus, anterior lobe large, setulose, rounded apically. Inner view of surstylus; eight small, black prensisetae along posterior margin, these slightly decreasing in size ventrally, a single strong seta present anterior to the line of prensisetae, anterior lobe large and setulose. Hypandrial apodeme with wide lateral margin, much wider than usual for a Silba species. Postgonites in posterior view y-shaped, a single strong setula on the outer limb and 4–5 setulae on the inner. Pregonite long and thin, deeply bifurcated apically, outer part with a long, strong seta on inner margin. Phallus a simple U-shaped tube, partly translucent at base, extending beyond basal section, with a pair of translucent lateral processes emerging from the medial surface of the basal section, these relatively short only reaching half way to the apical section.

Female: Unknown.

Diagnosis. This species with a very wide hypandrial apodeme, bifurcated pregonite and translucent lateral processes to the phallus is clearly distinct amongst the described Afrotropical Silba species.

Type material: Holotype: 1♂. TOGO: Zogbégan , village part Zogbégan-Carriére (SE of Badou), at Elèbè creek, 7.5805N 0.6675E, 20– 25.4.2008, 650m, secondary rainforest, leg. M. von Tschirnhaus. Specimen deposited in SDEI; SDEI-Dip-01006.

Paratypes: 2♂ with the same data as the holotype. Specimens deposited in NMS; NMS- 10022286 & 10022295 .

Etymology. The specific epithet refers to the town near which the type material was collected.

Figures

FIGURES 34–38. Silba zogbegani sp. nov. 34. Epandrium and associated structures, lateral view. 35. Same, ventral view. 36. Inner surface of surstylus. 37. Hypopygium and associated structures, posterior view. 38. Phallus, lateral view, TP = translucent projection.