Silba nigrispicata, Introduction & Fallén & Morge, 2007

Introduction, Iain, Fallén, Lonchaea & Morge, Setisquamalonchaea, 2007, New pecies of Lonchaeidae (Diptera: Schizophora) from Asia, Zootaxa 1631, pp. 1-32 : 28

Silba nigrispicata sp. nov.

Description: Holotype male: Head: Eyes bare. Frons wide, approximately three quarters eye width, subshining black covered in microsculpture and small pock marks from which the interfrontal setulae arise, frontal and interfrontal setulae minute, not more than one eighth the length of orbital setae. Orbital plate shining and bare of setulae. Lunule with three setulae on each side, ground colour light brown with a very slight silver dusting, face shining black ventrally, slightly silvered dorsally, parafacials dorsally shining black, ventrally slightly silvered. Anterior genal setulae in single row of five along mouth margin, slightly separated from other setulae on the genae, all relatively long, and becoming longer basally, nearly all slightly stronger than other setulae on genae. Antennal flagellomere two and a half times as long as deep, just reaching the mouth margin, entirelly matt black. Arista entirely black, plumosity at its greatest extent just less than depth of flagellomere.

Thorax: disc glittering black, pleurae dusted. Anepisternum damaged but apparently with two anterior and three posterior setae. Katepisternum with two strong setae, anterior one weaker than the posterior. One propleural and one finer stigmatical setae. Scutellum badly damaged and as a result the chaetotaxy is unclear. Squamae pale with a pale fringe. Wings clear with yellow veins. Wing length 3.7mm. Legs, entirelly black.

Male terminalia; Figs. 60–62. In lateral view epandrium as high as wide, rounded ventrally with a circular excavation posterodorsally, bearing a row of setulae on ventral margin the posterior five of which are longer and stronger than the others. Cerci rather rectangular, about half the height of epandrium, bearing moderately long setulae apically and along the ventral margin which is also slightly sclerotised. Surstyli extending posteroventraly and anteriorly beyond shell of epandrium as a small, rather round ended process. In ventral view basal plate of surstyli bearing six sharp, black teeth. Aedeagus complex, basal part broad with extending from it on the lower third the intromitent organ, gently curved upwards and extending to just slightly more than the height of the basal portion, basally with a pair of lateral projections slightly notched at the apex and arising at the base of these a straight, upright process with a slender tip which lies up against the intromitent organ, these basal projections and processes all sclerotised and black.

Female: Unknown

Differential diagnosis: This is another Silba species which externally is similar to many others in southeast Asia. Examination of the male terminalia however reveals its uniquely shaped aedeagus which immediately distinguishes it from other known species.

TYPE MATERIAL: Holotype male. TAIWAN: Nantou Hsien, Shuili , forest undergrowth, No. 12, 30.ix.2000, leg L. Papp.

Only known from the holotype in the HNHM .

Etymology. The specific epithet refers to the black, spike-like process on the male aedeagus.