Scatella (Scatella) obsoleta Loew, 1861

Zatwarnicki, Tadeusz & Irwin, Anthony G., 2018, Taxonomic notes on the genera Scatella and Scatophila (Diptera: Ephydridae) with a remark on Trixoscelis chilensis (Trixoscelididae), Zootaxa 4377 (1), pp. 91-109 : 97-98

Scatella (Scatella) obsoleta Loew

( Fig. 9 )

Scatella obsoleta Loew, 1861: 358 .

Scatella callosicosta Bezzi, 1895: 70 , synonymized by Olafsson, 1991: 28. Scatella strandi Duda, 1942: 31 , synonymized with S. callosicosta Bezzi, 1895 by Papp, 1979: 103. Scatella lutosa var. nigripes Oldenberg, 1923: 315 , new synonym. Scatella lutosa nigripes: Becker, 1926: 80 .

Type material examined: The lectotype female of Oldenberg's species, herein designated, is double mounted in good condition without right arista, labelled: "Mehadia 6. 6. 04 " (handwritten), " Type " (pink, handwritten), " Scatella luteata m. Old." (handwritten), "112" (handwritten by pencil), "58" (handwritten), " lutosa v. nigripes m. Old." (handwritten), " Typus " (red), "coll. Oldenberg", " Typen (var)" (pink; “var” underlined), and 5 paralectotypes: two females (in good condition but without heads) labelled: "Mehadia 7. 6. 04 " (handwritten), " ♂ " (handwritten), " Typen " (pink, handwritten), " Scatella luteata m. Old." (handwritten), " Typus " (red), "coll. Oldenberg", " lutosa v. nigripes m. Old." (handwritten); two females in good condition labelled: "Mehadia 7. 6. 04 " (handwritten), " Typen " (pink, handwritten), " Scatella luteata m. Old." (handwritten), " Typus " (red), "coll. Oldenberg", " lutosa v. nigripes m. Old." (handwritten); one female in good condition (wing punctured by minutia pin, abdomen partially detached from the thorax) labelled: "Mehadia 13. 6. 04 " (handwritten), " Type " (pink, handwritten), " Scatella luteata m. Old." (handwritten), "58" (handwritten), " lutosa v. nigripes m. Old." (handwritten), " Typus " (red), "coll. Oldenberg". All the types preserved in SDEI.

Other material examined: CZECHIA: Bystřice near Třinec , shores of river Olše , 49°38'08'' N, 18°42'26''E, 27.–28. V. 2005, M. Barták, 1 ♂ ( CULSP) . FINLAND: Helsinki (“ Helsingfors ”), Murea küste, 44030, 25. VII. 1898, T. Becker, 1 ♂ ( ZMHB) . HUNGARY: Duna-Dráva N. Park, Kölked , 8. VI. 2003, L. Papp, 2 ♂ ( HNHM) . POLAND: Jedlina-Zdrój (“ Charlottenbrunn ”), 32196, 8. VII. 1893, T. Becker, 1 ♂ ; Legnica-Przybków (“ Liegnitz am Prinkendorf ”), 33233, 10. IX. 1893, T. Becker, 1 ♂ ; Malczyce (“ Oderwald ”), 14. V. 1896, T. Becker , 1 ♂ ( ZMHB) ; ROMANIA: Mehadia , 3–7. VI. 1904, 10 ♂ ( SDEI) ; 7.–8. VI. 1904, Kertesz, 8 ♂, 4 ♀ ( HNHM); Orsova, 37680, 25. VI. 1895, T. Becker , 1 ♂ ( ZMHB); Voineasa , pasture near river, 23. VII 1987, M. Barták, 2 ♂, 1 ♀ ; Stoenesti , pasture nr. river, 44.08N / 24.30E, 14. VII. 1987, M. Barták, 1 ♂ ( CULSP) . SWITZERLAND: Ticino: Tenero , 29. VIII. 1 992, G. Bächli, 2 ♂, 2 ♀ ( ZMHB) . USA: Illinois: Quincy, Canton, ufer des Mississippi, 3. IX. 1994, V. Hollmann-Schirrmacher, 1 ♂, 2 ♀ ( ZMHB) . Maryland: Calvert County, Scientists Cliffs , 2. VI. 1977, W. N. Mathis, 35 ex. ; North Carolina: Nags Head , 15. IV. 1954, W. W. Wirth, 35 ex. ( USNM) . Virginia: Beach, Seashore St Park, 2. XI. 1989, L. Papp , 6 ♂, 3 ♀ ( HNHM).

Type localities. " Washington " (DC, USA) for the senior synonym. Oldenberg (1923) provided "Herculesbad" now called Baile Herculane in Romania (coordinates 44°52'6.9" N, 22°24'32.3" E). The city belongs to the commune Mehadia, which is located in SW part of Romania.

Diagnosis. This species belongs in the stagnalis group of Scatella s.s. It is distinguished from other species by the greatly swollen first costal section of male ( Fig. 9 ), the brownish-yellow face, and the heavily dusted frons. Scatella bullacosta and S. costalis males also have a swollen first costal section, but they have a thinly-dusted, shining frons. The epandrium in S. obsoleta has long, dense hairs at its apex, whereas these are short and sparse in S. bullacosta . Male terminalia illustrated by Olafsson (1991; figs 13d–e, page 28) and Beshovski (2009, fig. 143, page 361).

Distribution. Nearctic: Canada, United States. Palaearctic: Bulgaria, Czechia, Denmark, Finland, Germany, Great Britain, Greece, Hungary, Italy, Japan, Lithuania, Morocco, Norway, Poland, Romania, Russia (European Territory, Far East), Spain, Sweden, Switzerland.

Remarks. Cogan (1984) ignored the name nigripes ; later Olafsson (1991: 29) synonymized Oldenberg's variety with the nominative name, which is incorrect. S. obsoleta Loew is a dimorphic species—the male has characteristic thickening of first costal section, but the female is more difficult to separate from other Scatella species. Identification of S. lutosa nigripes was prompted by the presence in the collection of SDEI of ten males of S. obsoleta with characteristic thickening of the basal part of the costa, bearing the same locality labels as the junior synonym—"Mehadia". All six type specimens represent females of Scatella obsoleta Loew. The type specimen of the senior synonym, which is preserved in Museum of Comparative Zoology (Cambridge, USA), was not examined, but its interpretation is based on key characters of this distinctive species provided by Olafsson (1991).

Figures

FIGURES 8–9. Habitus, antero-oblique view. 8. Scatella lacustris (Meigen, 1830) (Czechia: Bystřice near Třinec, shores of river Olše, 49.38°N/18.43°E, 29. V. 2004, M. Barták; CULSP). 9. Scatella obsoleta Loew, 1861 (Poland: Wrocław, TZPC). Scale bar = 0.5 mm.