Nocticanace mahensis ( Lamb, 1912 )

Munari, Lorenzo, Kirk-Spriggs, Ashley H. & Mcgregor, Gillian K., 2021, The surf flies of the Mascarene Islands (Diptera: Canacidae: Canacinae), with the description of a new species, Zootaxa 4990 (3), pp. 563-570 : 568

Nocticanace mahensis ( Lamb, 1912)

Figs 9, 11

Distribution. Afrotropical: Mascarenes ( La Réunion *, Mauritius *), Seychelles (Aride, Coetivy, Long and Mahé Is.).

Material examined. La Réunion: 50♂, 32♀, Grande Anse , 21°22′17″S, 55°33′00″E, 0–12 m, 26.x.2015, gen- eral sweeping: secondary forest, intertidal rocks and coral beach, A.H. Kirk-Spriggs & M.J. Ebejer (5♂, 2♀ MJEC (Ebejer det.); 3♂, 1♀ LMC) ; 2♂, 4♀, Mare d’Azule , réserve biologique, 21°21′52″S, 55°46′25″E, 0–8 m, 7.xi.2015, general sweeping: coastal habitats, M.J. Ebejer (all MJEC (Ebejer det.)) ; 1♂, Pointe de Tremblet , 21°17′34″S, 55°48′21″E, 0–9 m, 9.xi.2015, general sweeping: intertidal zone and sandy beach, M.J. Ebejer ( MJEC (Ebejer det.)) ; 1♂, 3♀, Rivière des Remparts , 21°23′00″S, 55°37′07″E, 15 m, 10.xi.2015, general sweeping: river bed, M.J. Ebejer (all MJEC (Ebejer det.)) ; 2♂, 2♀, St.-Louis, Rivière St.-Étienne , 21°17′54″S, 55°24′07″E, 0–9 m, 18.x.2015, general sweeping: intertidal rocks and vegetated gravel plain, M.J. Ebejer (all MJEC (Ebejer det.)) ; 10♂, 7♀, St.-Paul , beach, 20°58′15″S, 55°16′56″E, 0–5 m, 21.x.2015, general sweeping: intertidal and woodland zone and park, A.H. Kirk-Spriggs & M.J. Ebejer (2♂ MJEC (Ebejer det.); 1♂ LMC) ; 18♂, 17♀, St.-Pierre, Pointe de Pont , 21°20′51″S, 55°28′52″E, 0–6 m, 13.xi.2015, general sweeping: intertidal rocks and coral beach, A.H. Kirk-Spriggs & K. Jordaens (1♂, 1♀ LMC) . Mauritius: 1♂, 1♀, Butte aux Sables , 20°29′39″S, 57°37′26″E, 1–3 m, 27.i.2018, sweeping intertidal zone and coastal vegetation, A.H. Kirk-Spriggs & B.S. Muller ; 1♂, 2♀, Flacq, Poste Lafayette , 20°07′02″S, 57°45′05″E, 1–3 m, 30.i.2018, sweeping intertidal zone and coastal vegetation, A.H. Kirk-Spriggs and B.S. Muller ; 1♂, Pamplemousses, Tombeau Bay , 20°08′00″S, 57°29′54″E, 1–3 m, 30.i.2018, sweeping intertidal zone and coastal vegetation, A.H. Kirk-Spriggs & B.S. Muller .

Comments. By far the most common surf fly species on Seychelles and the Mascarene islands. The male surstyli of Mascarene islands specimens were examined from different collecting stations and proved to be similar in all respects to those figured by Mathis (1982b, figs 4‒6), but exhibit a row of four to five pale brown, translucent spine-like setulae on the posterior margin, which are only visible under high magnification using a compound microscope. The illustration provided by Mathis (1982b, fig. 6) exaggerated the width and colour (piceous black) of these spine-like setulae. Otherwise, the shape and size of the surstyli are quite similar to those of the specimens examined here.

Figures

FIGURES 7‒11. Mapped coastal sampling stations of surf flies in the Mascarene islands and distributions of species. 7. Map of sampling stations on La Réunion (2015). 8. Same, Mauritius (2018). 9. Distribution of Nocticanace mahensis (Lamb) on La Réunion. 10. Same, Isocanace mauritiana Munari sp. nov. on Mauritius. 11. Same, Nocticanace mahensis (Lamb), Procanace pninae Mathis & Freidberg and Procanace sp. grisescens-group on Mauritius.