Colobostema auberti, Jean-Paul Haenni, 2013

Jean-Paul Haenni, 2013, A revision of the West Palaearctic species of Colobostema Enderlein, 1926 (Diptera, Scatopsidae). Part I. European subregion, Mitteilungen Der Schweizerischen Entomologischen Gesellschaft 86, pp. 199-242 : 205-206

Colobostema auberti sp. n.

( Figs 1 A-H)

Colobostema auberti Haenni, 1998 : Fauna Helv. 1, Diptera Checklist: 141, nomen nudum’, Haenni, 1999: Checkliste Dipt. Deutschl. Studia Dipt. Suppi. 2:74, nomen nuclum.

Type locality. SWITZERLAND, canton Neuchâtel: St Blaise .

Material examined. Holotype ♂, labelled: «SUISSE-NE: St. Blaise (Le Villaret), 550 m, 23.V.1979, J.-P. Haenni leg.», « S2810 », «HOLOTYPE Colobostema auberti n. sp. ♂ Haenni , 2010» : the holotype is slide-mounted in collection of MHNN. Paratypes (2 ♂ ♂, 1 ♀): same data as holotype, except « S2811-13 » in coll. MHNN .

Other material. ANDORRA, Vail Sant Roc ( Santa Coloma ), 1050 m, 1 ♂, 1-15.VI. 1993, J. Pujade, FBUBA . - AUSTRIA. Kärnten, Bad Villach , 24.VII.1927, 1 ♂, Oldenberg, DEI (labelled « femoralis Mg. Oldbg», « tristis Zett. ♂ d. Duda ») . — FRANCE. Alpes-Maritimes: Thorenc (Le Plan du Peyron), 1150 m, 14.VI.1994, 1 ♂, J.-P. Haenni, MHNN ; Doubs: Quingey , 750 m, 1.VIII. 1990, 1 ♂, 1 ♀, M. Bartâk, CMB . - GERMANY. Nordrhein-Westfalen: Bielefeld (Johannisberg), 21.IX.1983, 1 ♂, M. von Tschirnhaus, FBUB . Thüringen: Leutra BEI Jena, NSG Leutratal , 18-28.IV. 1995, 1 ♂, R. Bellstedt, MNG . - SLOVAKIA. Hegy Farok , 180 m, 24.VII.1989, 1 ♂, M. Bartâk, CMB . - SPAIN. Gerona: Olot (Las Presas, Sant Privat d’en Bas ), 20.VI. 1985, 1 ♂, M. von Tschirnhaus, MHNN . - SWITZERLAND. BL: Bubendorf , 6-13.VII.2000, 1 ♂, M. Wolf, CGB ; GE: Bernex-Signal , 510 m, 2.V.2008, 1 ♂, B. Merz, MHNG ; NE: Gorgier ( Les Ouches ), 1M 3.V.1976, 2 ♂♂, d’Agostini, MHNN ; Le Cachot , 1050 m, 29.V.1974, 1 ♂, W. Matthey, MHNN ; TI: Vezia S. Martino , 410m, 20-26. VIII. 1979, 1 ♂, C. Dufour & W. Geiger, MHNN ; Boscior, Medeglia , 945 m, 1.VIII. 1991, 1 ♂, F. Rampazzî, MSNL ; same, 3.IX.1992, 1 ♂ ; Campra di Là ( Olivone ), 1425 m, 10-19.VII.1994, 1 ♀, L. Pollini, MSNL ; Locarno env. ( Monte Bré ), dates ranging from 25.III to 22.IV.1997, 2 ♂♂, M. Moretti, MSNL / MHNN (detail of captures in Haenni & Moretti in prep.) ; VD: Onnens ( Chassagne ), 530 m, 13.V.1979, 1 ♂, J.-P. Haenni, MHNN ; Lutry , 20.VII.1954, 1 ♂, J. Aubert, MZL ; same, 25.IV.1955, 1 ♂ ; same, 1.VII.1956, 1 ♂ ; VS: Salgesch ( Bois de Finges ), 540 m, 17.VI.1997, 4 ♂♂, J.-P. Haenni, MHNN ; Jeizinen , 26.VI.1999, 1 ♂, G. Bächli, CGB .

Diagnosis. C. auberti may be readily distinguished from all other species of the genus in males by the shape of tergite 7 ( Fig. 1 A-B), nearly pentagonal or practically square with a short rounded median posterior projection (shape variable according to the angle of view), and at the same time short transverse, practically symmetrical posterior projections of the epandrium (Fig. IE).

Description. Male. 2.0-2.3 mm; body generally dull black as usual, covered with dense dark microtrichosity, except katepisternum, lower part of meron and mediotergite, devoid of microtrichosity, shining black; base of wing fulvous brown, wing membrane very slightly tinged brownish, costal cell somewhat darker, anterior veins brown, posterior veins light brownish, hardly contrasting with membrane; halter black with contrasting fulvous stem; legs dark brown except yellowish-brown contrasting basal fourth-fifth of tibiae, tarsomeres 1-3 yellowish brown, 4-5 darker brown; pregenital abdominal segment weakly shining, aedeagus fulvous brown.

Head. Eyes separated on frons by about width of median ocellus; antennae as long as thorax, flagellomere 1 lighter at extreme base, longer than wide, 2 as long as wide, 3 to 7 wider than long, last somewhat shorter than 2 preceding ones together.

Thorax. Notum square, practically as long as wide; wing (Fig. IF), 2.5-2.6 mm long; Mj with angle not very marked, and stem of vein very short if present; stem of M vein practically as long as fork M, M2.

Abdomen. Segment 7 with a complete sclerotized basal ring; tergite 7 ( Fig. 1 A-B) in the shape of a roughly trapezoidal plate, that may appear also more or less squared, with a short rounded median projection; sternite 7 with a shallow V-shaped median posterior emargination ( Fig. 1 C); genital capsule (Fig. I D) rounded, gonocoxites triangular, rather massive, parameres with rather blunt apex, epandrium apically with a short, slightly asymmetrical, paired transverse projection (Fig. IE), aedeagus of medium length, thick, somewhat enlarged at apex.

Female. As male in general colour and appearance; base of first antennal flagellomere contrasting yellow; tergite 7 with posterior margin entire, slightly undulated ( Fig. 1 G); sternite 8 bearing a pair of elongate, apically rounded and somewhat inflated valvifers and a pair of submedian sclerotized plates basally ( Fig. 1 H).

Taxonomic remarks. The manuscript of this revision was already in an advanced stage of elaboration in the early 1990’s, and this was the reason for the inclusion of C. auberti in the Swiss and German Diptera checklists ( Haenni 1998, 1999). However, its publication (and thence the description of this new species) was then unfortunately delayed for years. The quotation of C. auberti in Haenni (1998, 1999) must thus be considered as nomen nudum.

Distribution. This species appears to be widely distributed in Central Europe, where it is known from about 20 localities ranging from the Pyrenees ( Spain, Andorra), France, to Switzerland, Germany, Austria and Slovakia.

Ecology. Most specimens have been collected by sweeping in various herbaceous habitats, with preference for thermophilous meadows. The flight period extends from end of April to September.

Derivation of name. The new species is named in memory of the distinguished Swiss entomologist, the late Prof. Jacques Aubert, from Musée cantonal de Zoologie in Lausanne, who collected the first specimens of this new species and introduced the author into the fascinating world of Diptera many years ago.

Figures

Fig. 1. Colobostema cuiberti sp. n.: A-B. Tergite 7, ♂, under different angles of view. - C. Sternite 7, ♂. - D. Genital capsule, ♂, ventral, - E, Epandrium, ♂, distal part, dorsal. - F. Wing venation, ♂ ■ - G. Tergite 7, ♀. - H. Stemite 8, ♀, (detail) with left submedian sclerotized plate and valvifer. (abbreviations: ae = aedeagus; g = gonocoxite; p = paramere; sp = sclerotized plate; v = valvifer 8).