Lonchaea lateralis MacGowan

Iain Macgowan & Gerhard Bächli, 2016, New species of Lonchaeidae (Diptera) from Switzerland and Serbia with arevised checklist of the Swiss fauna, Mitteilungen Der Schweizerischen Entomologischen Gesellschaft 89, pp. 169-176 : 173

Lonchaea lateralis MacGowan sp. nov.

( Figs 5–8 )

Description.Male. Head: Eyes bare. Frons at narrowest point just slightly less than the width of an eye, ratio 1to 1.1, matt black, slightly dulled by dusting, margins shining as is upper third, frontal and interfrontal setulae approximately 0,3x length of orbital seta, longer on anterior margin above lunule. Orbital plate shining, bare apart from orbital seta. Lunule black, bearing approximately 6setulae, face and parafacials slightly grey dusted. Antennal flagellomere with length to depth ratio 2.6:1, black apart from orange area basally on inner surface, arista microscopically pubescent. Anterior genal setae in asingle row of 9–10 along mouth edge, these becoming progressively stronger posteriorly where they are the strongest setulae on the gena.

Thorax: Scutum and scutellar disc shining blue black. Anepisternum with 3 anterior setae and four posterior, remainder of sclerite covered with rather numerous setulae almost half as long as the setae. Katepisternum with one long, strong seta, no setulae posterior to this. Prosternum bare. One seta on proepimeron and one on proepisternum. Calypteres pale with aslight yellowish tinge as has the fringe. Scutellum on margin with 5setulae on each side between lateral setae, 4 between apical setae, these long, approximately 0.5x as long as the marginal setae. Wing slightly yellow tinged on anterior half, veins yellow brown. Wing length 3.9 mm. Legs black apart from the yellowish basal, 2nd and 3rd tarsomeres of each leg.

Male terminalia: In lateral view epandrium broadly rectangular in shape, slightly wider than it is high, with arow of strong setae along posterior and ventral margins, most of these at least half as long as the depth of the epandrium, two on the posterior margin noticeably longer than the others, surstylus protruding beyond ventral margin of epandrium as alow process, slightly concave ventroapically, protruding anteriorly as asmall setulose process, cerci relatively large, their height almost equalling the depth of the epandrium, bearing afringe of long setulae along the ventral and posterior margins. Inner surface of surstylus with ascattered vertical row of approximately 25 setae, afew scatted between this and the row along the ventral margin, anterior process covered in short fine setulae. Phallus two segmented, in lateral view basiphallus simple and boat-shaped, distiphallus orientated at aright angle to it and almost as long as basiphallus, forming asimple slightly sinuous tube, apex slightly flared, basally with aflange like lateral process on each side, these slightly serrated along their outer margins.

Differential diagnosis.With bare eyes, uniserial setulae on the anterior part of the genae, yellow tarsomeres, pale calypteres, asingle seta on the proepimeron and bare orbital plate, this species lies near the species such as L. nitidissima Kovalev, 1978 within the European fauna. It is however easily differentiated by the shape of the phallus, in particular the distiphallus which has characteristic basal lateral processes.

Material examined. Holotype ♁, SWITZERLAND: TI: Bodio, iv–xi.2007, leg. G. Roggero, deposited in the National Museums of Scotland. 1 Paratype ♁, TI: Gentillino , iv–xi. 2007, 469 m, leg. G. Roggero.

Etymology.the specific epithet refers to the lateral processes at the base of the distiphallus.

Figures

Figs 5 – 8. Lonchaea lateralis sp. nov. — 5. Epandrium and associated structures, lateral view. — 6. Internalviewofsurstylusandassociatedstructures. — 7. Phallus, lateralview. — 8. Phallus, anterior view.