Colobostema triste ( Zetterstedt, 1850 ), 1986

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 : 233-238

Colobostema triste ( Zetterstedt, 1850)

( Figs 11 A-G)

Scatopse tristis Zetterstedt, 1850 : Dipt. Scand. 9: 3404.

Colobostema oldenbergi Enderlein, 1926 : Zool. Anz. 68(5/6): 140.

Scatopse tristis Zetterstedt, 1850 : Duda, 1928: Fliegen pal. Reg. 2(1)5: 39, Figs 37a-c, PI. I, Fig. 9 ; Krivosheina, 1969: Opred. nasekom. Evrop. Chast. SSSR 5(1-2): 422, Fig. 243(4); Krivosheina, 1989: Keys Ins. Europ. Part SSSR 5(1): 650, Fig. 243(4).

Scatopse sziladyi ( Zilahi-Sebess, 1956) : Acta zool. Hung. 2(4): 435, Figs 3-4 . syn. n.

Colobostema triste ( Zetterstedt, 1850) : Cook, 1956: 328, Figs 1 A, 2A, 3A; Cook, 1974: J. nat. Hist. 8: 63, Figs 1 , 2 , 71, 72, 75; Freeman, 1985: Hdbk Ident. Br. Insects 9(7): 39, Figs 125-128; Krivosheina & Haenni, 1986: Cat. pal. Dipt. 4: 305; Krivosheina 2000: Entomol. Obozr. 79(2): 493, Figs 1 (3), 2 (1), 4(6-11), 5(1-2).

Type locality. DENMARK [«Hab. in Dania»].

Material examined. Holotype: ♂, without locality, labelled as follows: «Zett. det. A» [square label with triple red thread, in Zetterstedt’s handwriting] / «Coll. Staeger» [yellow printed label] / «ZOOL. MUS. K0BENHAVEN» [printed label] / « Colobostema triste Cook 68» [in Cook’s handwriting], I have labelled it « Scatopse tristis Zetterstedt HOLOTYPE ♂, rev Haenni 1990». The type in ZMUC Copenhagen, was slide-mounted by Cook and is in fairly good condition, except for somewhat damaged head and thorax as well as one lacking antenna.

Other material. ANDORRA. Puerto de Envalira, 1800 m, 8.VII.I990, 1 ♂; same, 1400 m, 8.VIE 1990, 1 ♂, both M. Bartâk, CMB ( Haenni & Baéz 2002). - AUSTRIA. Styria, 1.VII, 3 ♂ ♂, G. Strobl, NHM A (2 ♂ ♂ labelled « Sc.tristis ♂ ♀ », 1 ♂ labelled « Sc. tristis v. obscuritarsis », det. G. Strobl). — BELGIUM. Heusden, 3.VI. 1928, 1 ♂, M. Goetghebuer, IRSNB (« Scatopse nigripennis Mg. det. M. Goetghebuer).— CZECH REPUBLIC. Horské Kvilda, 1000 m, 28.VI.1992, 2 ♂♂; Celakovice, 180 m, 10.IX.1991, 1 ♂; same, 2.V.1992, 1 ♂; Sumava, Jezemi Slat, 980 m, 7.VII.1988, 1 ♂; same, 21.V.1992, 1 ♂; Vrâz u Pisku, 400 m, 31.V-2.VI.1994, 5 ♂ ♂; Sumava Kyselovskÿles, 725m, 17.V.1997, 1 ♂; Sumava-Spalenec, 800 m, 3.VII. 1988, 1 ♂; Trinec-Sosna, 350 m, 9.V.1988, 1 ♂; Sumava-Popelné, 950 m, 4.VII.1988, 1 ♂; Sumava Borova Lada, 910m, 4.VI.1996, 1♂, M. Bartâk, CMB; Sumava, Chalupska Slät, 860 m, 17.VIII.1994, 3 ♂♂, M. Bartâk, CMB; Sumava Mts, Zhurské slaté, 1130 m, dates ranging from 18.V to 21.'VII— 21.VIII. 1999, 5 ♂ ♂, all M. Bartâk, CMB / MHNN; Sumava Mts, Rokytecka slat, 1100 m, 18.V-16.VI.1999, 3 ♂♂; same, 16.VI-21.VII. 1999, 2 ♂♂, all M. Bartâk, CMB / MHNN; Dobris (3 km W), 400 m, 19.V1.1988, 1 ♂; Velké Popovice (2 km SE), 470 m, 10.VI1.1988, 1 ♂; Mrtvy Luh u Volnar, 720 m, 5.VÏI.1988, 3 ♂ ♂, all M. Bartâk, CMB; Podyji NP: Flâdnickâ chata, 360 m, 29.IV-21.V.2004, 1 ♂, M. Bartâk & Kubik, CMB; Podyjf NP: HavranikI, 330 m, 26.HI- 16.V.2002, 1 ♂, Meixnerovâ, CMB. The author has studied 13 additional specimens from the Bilina-Duchcov area ( Haenni & Bartâk 2000) and from Podyji National Park ( Haenni & al. 2005). — FRANCE. Ain: Lavours, 25.VII.1986, 1 ♀; same,

8.VIII. 1986, 2 ♂♂; same, 1.IX.1987, 2 ♂♂, all J. Brunhes, MHNN; Doubs: Lac de Remoray S, 852 m, 5.VI.1993, 2 ♂ ♂, J.-P. Haenni, MHNN; Vuillafans, 360 m, 25.V. 1994, 1 ♂, J.-P. Haenni, MHNN; Haute-Marne: Wassy, 2.V. 1965, 1? ♀, BMNH ( C. triste , det. Cook, 1969); Isère: Lac Luitel, 16.V.1993, 1 ♂, P. Withers, CPW; Haute-Savoie: Salève (Téléphérique), 1100 m, 10.VIII.2000, 1 ♂, B. Merz & G. Bächli, MHNN; Landes: Léon (Escalus), 19.VII.2001, I ♂, J.-P. Haenni, MHNN; Puy-de-Dôme: La Barthe, 2.VII.1984, 1 ♂, J. Brunhes, MHNN; Chambedaze, 12.VII.1985, 1 ♀, J. Brunhes, MHNN; Aydat (Narse d’Espinasse), 1000 m, 11.VU.1995, 1 ♂, J.-P. Haenni, MHNN; Hautes-Pyrénées: Pic Long, 2200 m, 9.VII.1990, 1 ♂, M. Bartâk, CMB; Bas-Rhin: Val-de-Villé, 1 ♂, MNHN ( Haenni & Withers 2007). — GERMANY. Berlin, Potsdam Wildpark, 18. VI. 1920, 1 ♀, L. Oldenberg, (type of Colobostema oldenbergi Enderlein ), DEI; Berlin, Stand!'., I ♂, L. Oldenberg, DEI; Berlin, Finkenkrug, 5.V.1907, 1 ♂, L. Oldenberg, DEI; Potsdam, 18.VI.1920, 1 ♂, L. Oldenberg, DEI (these 3 specimens labelled « tristis d. Duda»; Kochelsee, Mülecker Filz, 22.VIT.1990, 2 ♂♂, F. Piichel, FBLJB. Nordrhein-Westfalen: Bielefeld, Johannisberg, 21, IX.1983, 4 ♂♂, FBUB; Scherfede (NSG), 28.V.1988, 1 ♂, M. von Tschimhaus, FBUB. Schleswig-Holstein: Mölln, Hellbachtal, 21, V. 1989, 1 ♂, M.von Tschimhaus, MHNN. Thüringen: Thüringer Wald, Schnellbach (Weidmannsruh), 27.V-25.VI.1999, I ♂, R. Bellstedt, MNG; Rhön, Volkershausen (Öchsenberg), 11.VI-25.VII.1999, 1 ♂, R. Bellstedt, MNG; Schiefergeb. Gahma Riesenbach, 450m, 22.V.2000, 2 ♂ ♂, R. Bellstedt, MNG. — GRE AT-B RIT A IN, England. Cambs, Wicken, 1.V.1904, 1 ♂, G.H. Verrall; Chippenham, 15.V.1904, 1 ♂, G.H. Verrall, (« Scatopse tristis Zett »); Suffolk, Barton Mills, 4.V.1939, 1 ♂, J.E. Collin; Suffolk, Chippenham, 21.IV.l939, 1 ♂, J.E. Collin; Warwickshire, 16.VIII.1968, 1 ♂, M.B. Green ( C. triste (Zett.) , det. Hutson 1969); Oxon, Waterferry Wood, 5.V.1940, 4 ♂♂, F.W. Edwards, («C. triste (Zett.) »); Scillies, Tresco, 6.X.1970, 1 ♂, A.M. Hutson, BMNH (placed in coll, under C. triste (Zett.) . Wales. Dyfed, Puncheston Common, 20.VII. 1987, 1 ♂, (C. triste (Zett.) det. P. Freeman); Dyfed, Gwann Garthenor, 4IX.1986, 1 ♂; Carnnefon, Rhosgyll Fawr, 14.VI1.1988, 1 ♂; Merioneth, Hermon Copper Bog,

25.VII.1988, 1 ♂, (C. triste (Zett.) det. P. Freeman, all in BMNH. - LITHUANIA. Sviencionis, distr.Prudiscis, 27.VL1983, 1 ♂, A. Stationyte, VUIZ ( Haenni 1993b). - NETHERLANDS. Zwammerdam, VII.1900, 1 ♂, De Meijere, (labelled « tristis Zett. d. Duda» and « Colobostema triste ( Zetterstedt, 1850) det. P.L.Th. Beuk 1993»), ZMA. — NORWAY. The author has studied 5 specimens from provinces B0, BV, and RY, detail of records in Haenni & Greve 2000); RY: Sandnes, near Figgjo, 9.V. 1993, 1 3, 0. Hâland, ZMUB - POLAND. Morskie Oro, Tatra Mts, 6.VII.1932, 1? ♀, D. Aubertin & E. Trewavas, BMNH (C. Isimplicinervis Duda det. Hutson 1972, C. nigripenne Mg. det. Freeman, 1987); Kwjawy Matuns, 15.V.1975, 1 ♂, R. Szadziewski, CRS (C. triste Zett. det. R. Szadziewski). — SPAIN. Irun, 5.V.[19’??], 1 ♂, G. Strobl, NHMA («5c. tristis Z.» [det. Strobl, f. genuina in cat. of coll.]). — SWITZERLAND. BL: Bubendorf, NSG Wildenstein, 7-14.IX.2000, 1 ♂; same, 14- 21.IX.2000, 1 ♂, both M. Wolf, CGB; GE: Bemex (Chante-Merle), 420 m, 7.VIII.2000, 3 ♂ ♂, B. Merz & G. Bächli, MHNN; Jussy (Prés de Villette), 8.VIII.2000, 1 ♂, B. Merz & G. Bächli, MHNN; GL: Elm, Wich len, 1300 m, 15. VIII.2001, 3 ♂♂, G. Bächli, CGB; Schwändital, 2000, 1 ♂, P. Duelli, CGB; GR: Savognin, 1360 m, 17-20.VIII.1988, 2 ♂ ♂, G. Bächli, CGB; Sur (Lai Neir), 1915 m, 3.VF2000, 4 ♂♂, J.-P. Haenni, MHNN; JU: La Chauxdes-Breuleux, La Tourbière, 980 m, 4.VI.2003, 2 ♂ ♂, J.-P. Haenni, MHNN; same, 28.VI.2003, 1 ♂, G. Bächli, CGB; LU; Luzern, 10.VI.2006, 5 ♂ ♂, G. Bächli, CGB; NE: Les Ponts-de-Martel, Bois des Lattes, 1000 m, dates ranging from 5.VIII to 13.1X4 986, 4 ♂ ♂, C. Vaucher-von Ballmoos, CCV; same, 4.VIII. 1989, 15 ♂ ♂, 6 ♀ ♀, J.-P. Haenni, MHNN; Le Cachot, 1050 m, dates ranging from 1.VI to 17.IX. 1973, 28 ♂ ♂, 1 ♀; same, dates ranging from 15.V to 29.V.1974, 9 ♂ ♂, all W. Matthey, MHNN; same, 30.VIII.1977, 1 ♂, W. Geiger, MHNN; same, dates ranging from 31.V to 5.VII. 1993, 10 ♂ ♂, 3 ♀ ♀, C. Vaucher-von Ballmoos, CCV and MHNN; SG: Schwändital, 2004, 1 ♂, P. Duelli, CGB; SO: Weissenstein, 25.VI.2006, 1 ♂, G. Bächli, CGB; VS: Morgins, Portes de Culet, 28.VII.2004, 1 ♂, G. Bächli, CGB; ZH: Dietikon, 390 m, 20.VII.1989, 1 ♂; same, 4.VII.1991, I ♂, both G. Bächli, CGB; Zürich, 550 m, 3 1.V-24.VI.1994, 1 ♂, A. Schaffner, CGB; Hönggerberg, 13-17.VI1.1996, I ♂, G. Bächli, CGB; same, 2-6.VIII.1997, 2 ♂♂, G. Bächli, CGB and MHNN; same, 5-7.VII.1998, 1 ♂, G. Bächli, CGB.

Diagnosis. Males of Colobostema triste are easily distinguishable from other species of the genus by the peculiar shape of tergite 7 ( Fig. 1 1 A), with a broad median posterior projection, appearing truncate or slightly concave according to the angle of view; the short triangular posterior projections of the epandrium are also characteristic ( Fig. 1 ID). The female has antennal flagellomeres 1 and 2 contrasting yellow, posterior margin of tergite 7 notched medially ( Fig. 1 I F), elongate valvifers and no submedian additional sclerotized paired plates on sternite 8 ( Fig. 11 G).

Description. Male. 1.5-2.1 mm. Body nearly entirely dull black, with dark pilosity, except lower parts of pleurae shining, a pair of hardly visible, fulvous spots at the posterior corners of thorax, apex of tibiae and tarsomeres I and 2 fulvous, somewhat contrasting according to the direction of light; extreme base of wings and stem of halters fulvous dark, hardly contrasting; wings practically translucent, slightly greyish with anterior veins brown and posterior veins translucent, not contrasting.

Head. Eyes separated by about a third or half of width of anterior ocellus, antennae somewhat longer than thorax, weakly widening towards apex; flagellomere 1 longer than wide, 2 about as long as wide, 3 to 7 wider than long, last somewhat shorter than the two preceding ones.

Thorax. Notum quadrate, as wide as long; wing (Fig. HE), 1.9-2.3 mm long. M, angled at V4 basal, with a hardly marked stem of vein; M1+2 shorter than medial fork.

Abdomen. Tergite 7 ( Fig. 11 A) with posterior median projection broad, truncate at apex; stemite 7 ( Fig. 1 1 B) broad, encompassing tergite 7, with posterior margin shallowly undulate; genital capsule as wide as long, with gonocoxites broadly triangular, apically rounded ( Fig. 11 C), parameres shortened, aedeagus thick, epandrium with posterior projection symmetrical, lateral lobes short, blunt apically ( Fig. 1 1 D).

Female. Like male in colour and general aspect, but antennal flagellar segments 1 and 2 contrastingly yellow; posterior margin of tergite 7 with a median notch ( Fig. 1 IF), valvifers of sternite 8 incurved, elongate ( Fig. 11 G).

Taxonomic remarks. Andersson (1978), who revised the Scatopsidae of the Zetterstedt collection in Lund, noticed that the type specimen of Scatopse tristis from Denmark (« ♀ », according to the original description by Zetterstedt 1850) «[...] is not present in Zetterstedt’s collection. It was probably returned to Staeger.» Actually, there are good reasons to think that the male specimen of C. triste present in the Staeger collection in ZMUC Copenhagen under the name Scatopse tristis is the type of this species. Although not clearly labelled as such, it was identified by Zetterstedt himself as Scatopse tristis . 1 have studied this specimen, which was slide mounted by Edwin F. Cook in 1968 —-but strangely not published by him in his «Synopsis of the Scatopidae of the palaearctic. Part III» ( Cook 1974)— and its identity is in accordance with the original description and also agrees with the usual concept of the species by subsequent authors.

The type of C. oldenbergi Enderlein, 1926 in DEI has also been examined; it clearly belongs to the same species, as established by Duda (1928).

The type (and only known specimen) of Scatopse sziladyi Zilahi-Sebess, 1956 was unfortunately destroyed during the burning of the Hungarian national Natural History Museum of Budapest in 1956 (L. Papp in litt.). According to the original description and drawings ( Zilahi-Sebess 1956), S. sziladyi is clearly a Colobostema species as may also be inferred from the fact that the species was compared with C. nigripenne in the original description ( Zilahi-Sebess 1956). The shape of tergite 7 and the genital features are very similar to those of C. triste , as far as can be seen from his Figures 3a and 3b, and the entire description is also applicable to this species, which is well characterized among the European Colobostema . Moreover, Zilahi-Sebess apparently ignored C. triste , since he did not include this widespread species in his key to the Hungarian species of the family Scatopsidae ( Zilahi-Sebess 1960) , where, in contrast, C. sziladyi is mentioned. The characters given to separate this species from C. nigripenne entirely apply to C. triste . According to this and to the fact that original specimens are not available anymore, the name C. sziladyi is considered here as a synonym of C. triste .

Distribution. C. triste is a widespread species in Europe, having been recorded with certainty from the following countries: Germany, Poland ( Cook 1956), Hungary ( Zilahi-Sebess 1956 [under the junior synonym name sziladyi j, Papp & Kaufman 1989, 1993), Sweden, Finland, Russia, France ( Cook 1974), Lithuania ( Haenni 1993b), France ( Withers 1994, Haenni & Withers 2007), Slovakia ( Martinovskÿ 1997, Kozanek & Roller 1997, Haenni 2009), Czech Republic ( Martinovskÿ 1997, Haenni & Bartâk 2000, Haenni & al. 2005), Switzerland ( Haenni 1986, Vauchervon Ballmoos 1997), Germany ( Schacht 1997, Haenni 1999, 2011), British Isles ( Chandler 1998), Norway ( Haenni & Greve 2000), Russia, Finland ( Krivosheina 2000), Andorra, Spain ( Haenni & Baéz 2002), Netherlands ( Beuk 2002).

Ecology. C. triste is a widespread species that may be caught in numerous biotopes; it is particularly frequent in peat-bogs and acidophilous meadows. The flight period extends from May to September. As other species of Colobostema , according to Enderlein (1926, under the synonym name C. oldenbergi ) this species may probably be myrmecophilous: Oldenberg caught one female specimen «[...] auf einem Baumstumpf sitzend, der unten mit Ameisen dicht besetzt war.» [«... staying on a stump which was underneath heavily occupied by ants»].

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).

Fig. 2. Colobostema dudai Krivosheina: A. Tergite 7, ♂. - B. Sternite 7, ♂. - C. Genital capsule, ♂, ventral. - D. Epandrium, distal part, dorsal. - E. Wing venation, ♂. - F. Tergite 7, ♀. - G. Sternite 8, ♀.

Fig. 3. Colobostema flavimanum (Strobl): A. Tergite 7, ♂. - B. Sternite 7, ♂. - C. Genital capsule, ♂, ventral. - D. Tip of aedeagus, ♂. - E. Genital capsule with epandrium, ♂, dorsal. - F. Wing venation, ♂.

Fig. 4. Colobostema geigeri sp. n.: A. Tergite 7, ♂, with diagrammatic outline of the posterior margin of an other specimen (below). - B. Stemite 7, ♂. - C. Genital capsule, ♂, ventral. - D. Epandrium, distal part, ♂, dorsal. - E. Tip of abdomen, ♂, lateral, (diagrammatic, pilosity omitted). - F. Wing venation, ♂. (abbreviations: ae = aedeagus; e epandrium; g = gonocoxite; st 7 - sternite 7; t 7 = tergite 7).

Fig. 11. Colobostema triste (Zetterstedt): A. Tergite 7, ♂. - B. Sternite 7, û. — C. Génital capsule, ♂, ventral. - D. Epandrium, distal part, ♂, dorsal, - E. Wing venation, ♂. - F. Tergite 7, ♀. - G. Terminalia, ♀, with sternite 8.

Fig, 9. Colobostema obscuritarse (Strobl): A. Tergite 7, ♂. - B. Sternite 7, ♂. - C. Genital capsule, ♂, ventral. - D. Epandrium, distal part, ♂, dorsal. - E. Wing venation, ♂.