Silba setiphallus, Macgowan, Iain, 2014

Macgowan, Iain, 2014, The Lonchaeidae of Fiji (Diptera: Schizophora), Zootaxa 3814 (4), pp. 537-552 : 545-547

Silba setiphallus sp. nov.

Description. Male: Head.; Eyes bare. Frons matt black with numerous short frontal and interfrontal setulae no more than 0.2x length of orbital seta. Orbital plate bare, subshining black, dulled by micro sculpture, bare apart from orbital seta. Lunule setulose with dark ground colour, light grey dusted as are face and parafacials. Antennae entirely black, 1st flagellomere 3x as long as deep. Arista with short plumosity, at maximum extent 0.5x depth of 1st flagellomere. Anterior genal setulae in single row along mouth margin, anterior 3 setulae well separated from the rest, none of these particularly strong.

Thorax: Dorsum subshining, slightly grey dusted, covered in rather coarse black setulae approximately 0.25x length of orbital seta. Thoracic sclerites subshining and slightly grey dusted, anepisternum with 2 strong anterior setae and 3 posterior, remainder of sclerite with scattered long black setulae. Katepisternum with two strong setae near dorsal margin, the anterior slightly shorter and weaker than posterior, four fine setulae anterior to anterior seta. Proepimeron with one setulae. Scutellum grey dusted, on margin between apical setae with 4 strong setulae, between lateral and apical setae with 2 setulae on the right side- the longest almost half the length of apical seta, left side with setulae rubbed off. Calypteres greyish brown with a dark fringe of uniform length. Wings slightly infuscated anteriorly, wing length 4.0mm. Legs entirely black including ventral fringe of anterior and posterior tarsomeres.

Male terminalia: ( Figs. 29–32 ) In lateral view epandrium 1.5x wider than high, bearing long setulae at posteroventrally cerci almost half the height of the epandrium, roughly rectangular in shape, bearing numerous fine setulae apically. Prensisetae and surstyli projecting beyond the shell of epandrium. Surstyli; in ventral view black peg-like prensisetae obvious on basal plate, 8 on one side and 7 on other, a pair of small setulae present below base of cerci, margin of surstylus extended into a lobe its margin bearing a row of setulae the posterior 4 of which are markedly longer and stronger than the rest. Phallus a stout J -shape with a basal lobe, main section covered in tiny setulae for most of its length, basal lobe simple.

Type material: Holotype ♂. FIJI ; Kadavu , 0.25 Km. SW Solodamu village, Moanakaka bird sanctuary, 19.078°S 178.121°E, alt. 60m, Malaise trap, 23.x–19.xi.2003. Schlinger & Tokota’a.

Other material: Viti Levu, Suva, “1920”, leg. Pemberton. 1 male.

Differential diagnosis: This species is best identified by its distinctive phallus. The relatively broad epandrium, surstyli with a row of large prensisetae and phallus with spicules and a basal lobe does show some affinities with S. longidentata MacGowan, 2007 currently only known from Thailand.

Figures

FIGURES 29 – 32. Silba setiphallus sp. nov. 29. Epandrium and associated structures lateral view. 30. Same ventral view. 31. Phallus lateral view. 32. Phallus ventral view.