Silba botanica, Introduction & Fallén & Morge, 2007

Introduction, Iain, Fallén, Lonchaea & Morge, Setisquamalonchaea, 2007, New pecies of Lonchaeidae (Diptera: Schizophora) from Asia, Zootaxa 1631, pp. 1-32 : 15-17

Silba botanica sp. nov.

The holotype has slightly collapsed when drying and not all the characters are easily seen.

Description: Holotype male: Head: Eyes bare. Frons narrow, narrowing from level of anterior ocellus to its anterior margin, at narrowest point approximately one quarter eye width, matt black, dulled with microsculpture, frontal and interfrontal setulae very short, a few longer ones present along the anterior margin. Orbital plates without setulae, brightly shining black. Lunule bearing two setulae, orange-brown in ground colour, covered with silver dusting. Parafacials and upper face also silvered. Anterior genal setulae in a single row of four or five along mouth margin, none of these especially strong. Antennal flagellomere just over twice as long as deep, entirely black apart from being obscurely brown ventrally basally on inner surface. Arista yellow basally, long plumose, plumosity at its greatest extent almost twice depth of antennal flagellomere.

Thorax: Disc shining, bearing short setulae at most one quarter length of orbital setae. Anepisternum with three strong setae anteriorly and three posteriorly. Katepisternum with two setulae, anterior one significantly weaker and shorter than posterior. One propleural and one finer stigmatical setae. Scutellum slightly damaged, brightly shining on the disc, apparently with no setulae between the strong setae. Squamae whitish with a white fringe. Wings clear with light brown veins. Wing length 3.0mm. Legs entirely black.

Male terminalia; Figs. 29 & 30. In lateral view epandrium almost twice as high as s wide, posteriorly rather pointed and culminating in a short process, anteriorly relatively broad and square ended, semi-circular excavation on dorsal margin, ventral margin with a row of short setulae along most of its length, a few setulae dorsally near the posterior apex. Cerci very small, not sclerotised, bearing a row of short setulae along dorsal margin. Surstyli almost completely enclosed within epandrium apart from a small, rounded anterior projection on the inner surface, with a continuous row of fourteen small teeth lying parallel to the ventral margin, the most posterior of these projecting posteriorly beyond shell of epandrium. Aedeagus with basal part relatively broad with a semi-circular excavation dorsally, outer portion long and narrow, half way along with a 45° bend, apex slightly flared.

Differential diagnosis: This species belongs to the Silba abstata McAlpine, 1956 group of species all of which are rather small, with a relatively short antennal flagellomere, an elongate epandrium with short cerci and with a row of teeth on the inner surface of the surstyli situated parallel to the ventral margin. McAlpine (1975) provided a key to the known species. With a pale squamal fringe and a simple aedeagus this species is most closely similar to S. lucens ( de Meijere, 1910) from Java and S. imitata McAlpine, 1964 from Australia. It is distinguished from both these species by having more teeth on the surstylus including one projecting posteriorly and by the more slender, angled aedeagus.

TYPE MATERIAL: Holotype male. THAILAND: Thung Khai Botanic Gardens, No. 38, primary lowland rainforest, 19.ix.2004, leg. Papp and Földvári.

Only known from holotype in the HNHM .

Etymology. The specific epithet refers to the Thung Khai botanic gardens in which the holotype was captured.