taxonID	type	description	language	source
03A07F56FFA2E946F8CFFEA584741532.taxon	description	(Figs 1 A – B, 2 A – B, 3 A, 4 A, 5 A – C, 7 A – E)	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA2E946F8CFFEA584741532.taxon	materials_examined	Type material. HoLoTYPF: J (Figs 1 A, 2 B, 4 A, 5 A, 5 B, 5 C, 7 A), labelled “ 20159 // Polska CF 16 // Kartoszyno // on Crataegus spp. // 3 VI 2021 // R. Żóralski leg. ” and with our red holotype label “ HOLOTYPE J // Orthonevra atlantica // Żóralski & Van de Meutter, 2024 “. Deposited in ZMHB. PARATYPFs: 61 JJ 14 ♀♀, all bearing our yellow paratype label: BELGIUM: Liège, univ. Sart Tilman, 1979, 1 J, leg. A. Pauly (RBINS); Oud-Heverlee, 28. iv. 1999, 1 J (Fig. 7 E), leg. FM (FMTB); Engsbergen, Achterheide, 22. v. 2011, 1 J, leg. FM (FMTB); Assent, Papenbroek, 5. – 19. iv. 2012, 1 J, Malaise trap, leg. FM (FMTB); Torgny, reservaat, 10. iv. 2015, 1 J, leg. FM (FMTB); Halma, Route Napoleon B, 8. iv. 2017, 1 J, leg. FM (FMTB); Froidfontaine, Tanton, 6. v. 2017, 1 J, leg. FM (FMTB); Teuven, Bos, 2. v. 2018, 1 J, leg. FM (FMTB); Bertrix, Rue de Muno, 22. iv. 2019, 1 J, leg. FM (FMTB); Buzenol, Montauban, 29. v. 2020, 2 JJ (GenBank acc. no. OR 859731), leg. FM (FMTB); Ovifat, Reinhardstein, 9. v. 2021, 1 J (GenBank acc. no. OR 859711), leg. FM (FMTB); Bertrix, Rue de Muno, 16. iv. 2022, 1 J (GenBank acc. no. OR 859697), leg. FM (RBINS). CZECH REPUBLIC: Jívová, u Dómského lesa, 540 m, on flowering Crataegus sp., 27. v. 2017, 5 JJ, leg. L. Mazánek (3 JJ LMJC, 2 JJ RZRP), 28. v. 2017, 1 J, leg. L. Mazánek (LMJC). GERMANY: Prov. Brandenbg., [no date], 1 J (ZMHB, ex. coll. Mehr); Niedersachsen, Harz-Südrand Hirseteich, 1 km NW Walkenried, 19. v. 2002, 2 JJ, leg. Stuke (ZFMK); Niedersachsen, Harz, Oberaue Zwischen Breitenbach und Unterzorge, 31. v. 2003, 1 J, leg. Stuke (ZFMK); Schleswig-Holstein, Kreis Ostholstein, Glinde südlich Schonwalde am Bungsberg, 54.1773 N 10.7536 E, 27. v. 2016, Malaise trap, 1 ♀ (GenBank acc. no. OR 859649), leg. GBOL-team, ZFMK-TIS- 2608557 (ZFMK); Schleswig-Holstein, Kreis Ostholstein, Erlenbruch am Masselberg bei Schwienkuhl, 54.2342 N 10.9154 E, 3. vi. 2016, Malaise trap, 1 ♀ (GenBank acc. no. OR 859696), leg. GBOL-team, ZFMK-TIS- 2608415 (ZFMK). NETHERLANDS: GE – Beek, Smorenhoek, 1. v. 2009, 1 J, leg. W. van Steenis (WSBN); ZH – Nieuwkoopse Plassen, kano aanlegplaats, 14. v. 2017, 1 J, leg. W. van Steenis (WSBN). POLAND: ♀ (Figs 1 B, 7 B) labelled “ 22154 // Polska CF 16 // Kartoszyno // on Crataegus spp. // 4 VI 2022 // R. Żóralski leg. ” and with our yellow paratype label “ PARATYPE (ALLOTYPE) ♀ // Orthonevra atlantica // Żóralski & Van de Meutter, 2024 ”; caught in copula with a male paratype, on the same Crataegus sp. as the holotype, but in the following year; it is on the same pin as the male paratype and deposited in ZMHB; Niemcza [= Nimpsch Schles. Duda; O. plumbago Lw.], 6. v. 1908, 1 J (ZMHB, ex coll. O. Duda); Puszczykowskie Góry, XT 29, 8. v. 2008, 1 J 1 ♀, in copula, leg. P. Trzciński (PTPP); Trzcielińskie Bagno, XT 19, 1. – 10. v. 2008, 2 JJ, Moericke trap, leg. P. Trzciński (RZRP); Trzcielińskie Bagno, 24. iv. 2010, 3 JJ, leg. P. Trzciński (PTPP); Jarosławiec, XT 29, 19. v. 2011, 1 J, leg. P. Trzciński (PTPP); Kartoszyno, CF 16 (all leg. RZ), 30. v. 2021, on Apiaceae near the stream, 1 J (Figs 2 A, 3 A) (MZPW), 3. vi. 2021, 2 JJ on Crataegus sp. (RZRP), 3. vi. 2021, 1 J on Crataegus sp. (ZFMK), 5. vi. 2021, 3 JJ 1 ♀ on Crataegus sp. (RZRP), 22. v. 2022, 2 ♀♀ (GenBank acc. no. OR 859735, OR 859692), in riparian forest near the stream (RZRP), 27. v. 2022, 2 JJ (GenBank acc. no. OR 859707, OR 859656) on Crataegus sp. (RZRP), 4. vi. 2022, 1 J caught “ in copula ” with allotype and deposited in ZMHB, 4. vi. 2022, 2 JJ 2 ♀♀ on Crataegus sp., leg. RZ (RZRP), 1 J 1 ♀ on Crataegus sp. (ZFMK), 28. v. 2023, 4 JJ (GenBank acc. no. OR 859675, OR 859668, OR 859677), 1 ♀ (GenBank acc. no. OR 859730) on Crataegus sp. (RZRP), 29. v. 2023, 3 JJ (GenBank acc. no. OR 859712) on Crataegus sp. (RZRP), 3. vi. 2023, 2 ♀♀ (GenBank acc. no. OR 859695, OR 859679) in riparian forest (RZRP); Stawiska ad. Miękinia, CA 95, 10. iv. – 5. v. 2022, 2 JJ, Malaise trap, leg. Ł. Mielczarek (LMMP); Słowiński National Park, O. O. Smołdzino, distr. 129 (old railway embankment), 16. v. 2022, 1 J, on Pyrus sp., leg. RZ (RZRP); Żegocin, marshy alder forest, XT 96, 30. iv. 2023, 1 J, leg. P. Żurawlew (RZRP). SERBIA: Tara, Manastir Rača, 43.9166667 N 19.535 E, 28. iv. 2012, 1 J, leg. Vujić A., Radenković S., Likov L. (FSUNS). SPAIN: Cortes de la Frontera, 15. iv. 2023, 1 ♀, leg. FM (FMTB); Capileira, 17. iv. 2023, 1 J, leg. FM (FMTB); Lugros, rio Alhama, 19. iv. 2023, 1 J (GenBank acc. no. PP 214180) (Fig. 7 D), leg. FM (FMTB); Sierra Nevada, vic. of Monachil, 1650 m a. s. l., near forest stream in Pinus - Quercus mountain belt, 37.13 N 3.44 W, 1 J, 24. iv. 2023, leg. Popov G. (SIZK). Additional material studied. 70 JJ 24 ♀♀. BELGIUM: Bonheiden, Dorstveld, 8. v. 1999, 1 ♀, leg. FM (FMTB); Diepenbeek, De Maten 8, 29. v. 2002, 1 ♀, leg. FM (FMTB); Tessenderlo, Engsbergen, Achterheide, 1. v. 2011, 1 ♀, leg. FM (FMTB); Assent, Papenbroek, 5. – 19. iv. 2012, 1 J, Malaise trap, leg. FM (FMTB); Holsbeek, Dunbergbroek, 2. v. – 2. vi. 2012, 2 ♀♀, Malaise trap, leg. FM (FMTB); Torgny, Réserve Naturelle Raymond Mayné, 10. iv. 2015, 1 ♀, leg. FM (FMTB); Ovifat, Reinhardstein, 5. vi. 2015, 1 ♀, leg. FM (FMTB); Oudenaarde, Bos t’Ename, 6. v. 2015, 2 ♀♀, leg. FM (FMTB); Meeuwen-Gruitrode, Itterbeek Eetsevelderbeek, 4. v. 2016, 1 ♀, leg. FM (FMTB); Lavacherie, Rue St. Ode, 30. iv. 2017, 1 ♀, leg. FM (FMTB); Awenne, Rue de Souvenir, 10. v. 2017, 1 ♀, leg. FM (FMTB); Champlon, Barrière de Champlon, 25. v. 2017, 1 J, leg. FM (FMTB); Léglise, 24. iv. 2021, 1 ♀, leg. FM (FMTB); Rossignol, Rue de Hageai, 24. iv. 2021, 1 J (GenBank acc. no. OR 859705), leg. FM (FMTB). CZECH REPUBLIC: Bílý Potok, nature reserve Nad koupalištěm, 430 m, wetland, 22. v. 2003, 1 J, leg. J. Preisler (LMJC) (MAZÁNFK et al. 2009, as O. brevicornis); Mníšek u Liberce env., 400 m, meadow, 24. v. 2003, 3 JJ, leg. J. Preisler (LMJC) (MAZÁNFK et al. 2009, as O. brevicornis); Jizerské hory Mts, Nature reserve Meandry Smědé, pond Dubák env., wetland, alder, Malaise trap, 19. v. – 31. v. 2005, 3 JJ 3 ♀♀, leg. J. Preisler & P. Vonička (LMJC) (MAZÁNFK et al. 2009, as O. brevicornis); Jívová, u Dómského lesa, 540 m, on flowering Crataegus sp., 27. v. 2017, 4 ♀♀, leg. L. Mazánek (2 ♀♀ LMJC, 2 ♀♀ RZRP), 28. v. 2017, 3 ♀♀, leg. L. Mazánek (LMJC). Sedm Dvorů, Bystřice valley, 510 m, sweeping on flowering Salix sp., 10. v. 2021, 1 J, leg. L. Mazánek (LMJC); Krkonošský NP, Vítkovice, 650 m, on flowering Crataegus sp., 8. vi. 2022, 1 J, leg. L. Mazánek (LMJC). DENMARK: Langaa, Dania: EJN, 2. vi. 1987, 1 J, leg. J. A. W. Lucas (RMNH). FRANCE: Savigny, la Prairie, 23. iv. 2010, 1 J, leg. X. Lair (XLSF); Ducey-les-Chéris, Bois d’Ardennes, 15. v. 2008, 1 J, leg. X. Lair (XLSF). GERMANY: Langballigau, Schleswig-Holstein / Nordangeln, 6. v. 1972, 1 J, leg. C. Claussen (ZFMK); Langballigau, 8. vi. 1976, 1 J, 10. vi. 1976, 3 JJ, leg. C. Claussen (ZFMK); 25 km S Oldenburg, Ahlornerteiche, 10. v. 1980, 1 J, W. Barkemeyer (ZFMK); Langballigautal, Schleswig-Holstein / E of Flensburg, 14. v. 1983, 1 J, leg. J. A. W. Lucas (ZFMK); Flensburg, Schleswig-Holstein, Roikier See, 21. vi. 1987, 1 J, 22. vi. 1987, 2 JJ, leg. J. A. W. Lucas (ZFMK); LK Uelzen, Grosses Bruch bei Altenebstorf, 22. v. 1991, 3 JJ, 17. vi. 1991, 1 J, 6. v. 1995, 2 JJ, 25. v. 1997, 3 JJ, 7. v. 1998, 2 JJ, leg. D. Wolff (ZFMK); LK Uelzen, Galgenberg bei Grünhagen, Nordhang Quelliger Laubmischwald, 29. v. 1991, 1 J, v. 1997, 1 J, leg. D. Wolff (ZFMK); LK Uelzen, Niehof bei Veersen Erlen-Eschenwald, 18. v. 1992, 4 JJ, leg. D. Wolff (ZFMK); Insmühlen Umgebung, Lüneburger Heide, 7. v. 1994, 2 JJ, 10. v. 1994, 4 JJ, leg. J. - H. Stuke (ZFMK); LK Uelzen, im Sieken bei Westerweyhe quelliger Erlenwald, 12. v. 1994, 1 J, leg. D. Wolff (ZFMK); Darmstadt, Messel Buchenwald, 2. v. 1995, 1 J, leg. M. Hauser (ZFMK); LK Uelzen, Eitzener Bruch bei Eitzen, 9. v. 1998, 1 J, leg. D. Wolff (ZFMK); LK Stade, Surbrook b. Fredenbeck, 14. v. 1998, 3 JJ, leg. D. Wolff (ZFMK); Zorge, Neue Teich near Zorge, Harz, Niedersachsen, 18. v. 2002, 1 J, leg. W. van Steenis (WSBN); Harz-Südrand, Hirseteich, 1 km NW Walkenried, 19. v. 2002, 5 JJ, leg. J. - H. Stuke (ZFMK); Harz-Südrand, Oberaue zwischen Breitenbach und Unterzorge, 31. v. 2003, 1 J, leg. J. - H. Stuke (ZFMK); Markhausen, Niedersachsen, Emsland, Markatal SW Markhausen, 1. v. 2005, 1 J, leg. J. - H. Stuke (ZFMK). POLAND: Żegocin, marshy alder forest, XT 96, 7. v. 2023, 1 ♀, leg. P. Żurawlew (RZRP). SWITZERLAND: Chevroux, 8. – 15. v. 2020 (Malaise trap), 1 J, leg. Association de la Grande Cariçaie, Nina Perret-Gentil (MZLS). UNITED KINGDOM: Sutton, Sutton Park, 18. v. 1997, 1 J, leg. S. Falk (SFKU); Lewes, Mount Caburn, 17. iv. 2005, 1 J, leg. S. Falk (SFKU); Birdford-on-Avon, Marsh Farm, 14. vi. 2014, 1 J, leg. S. Falk (SFKU); Hampshire, Ashford Hangers, 30. v. 1987, 1 J, leg. R. B. Hastings (RMMU); West Norfolk, East Walton Common SSSI, 18. v. 2007, 1 J, 19. v. 2007, 1 J, leg. R. Morris (RMMU); East Suffolk, Walberswick, 2. v. 1990, 1 J, leg. R. Morris (RMMU).	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA2E946F8CFFEA584741532.taxon	diagnosis	Diagnosis. A black Orthonevra (Figs 1 A – B) with metallic reflections, completely black legs, shiny sternite I and suboval postpedicel (1.1 – 1.25 times as long as wide, sometimes slightly angular at tip regardless of sex) and largely black with orange-brown basoventral area. Males of O. atlantica sp. nov. are best distinguished from other Orthonevra by morphological characters of the terminalia. The characteristic shape of the surstylus, wide in the basal half of its length, then abruptly narrowing into a curved tip (Fig. 5 A), is a diagnostic character shared only with two other west Palaearctic species: O. brevicornis and the North-African endemic of the high Atlas O. bouazzai Kassebeer, 1999. Males of O. atlantica sp. nov. are easily distinguishable from these two species by further characters of the terminalia: O. brevicornis has several significant differences in the shape of the phallus, the postgonites and the posteroventral process of the surstylus (for details see species descriptions and compare Figs 4 A and 5 A – C with Figs 4 B and 5 D – F). Orthonevra bouazzai differs from O. atlantica sp. nov. in the shape of the postgonites with a slender anterodorsal tip and three denticles on its posterodorsal margin (Figs 10 – 11 in KAssFBFFR 1999). Males of O. atlantica sp. nov. are also distinguishable by non- - genital characters: from O. brevicornis mainly by having black hairs on the scutum and on the vertex (yellow in O. brevicornis) and from O. bouazzai (both sexes) by having a shorter and partly orange-brown postpedicel (elongated and black in O. bouazzai). Females of O. atlantica sp. nov. have an unmodified tergite V without a keel or incision, a shiny sternite I and a partly orange short postpedicel — a set of characters that differentiates them from the females of all other European Orthonevra species except for the females of O. brevicornis. Characters to distinguish females of O. atlantica sp. nov. and O. brevicornis are subtle and influenced by individual variability. The colour of the postpedicel of O. atlantica sp. nov. is black with a restricted orange-brown area basoventrally, whereas the orange-brown area extends more to the tip in O. brevicornis with the dark areas often being brown instead of black. A subtle but generally good indicative feature is found in the wing venation: if we draw an imaginary line between the vein junctions M 1 / M 2 and C / R 2 + 3, the junction M 1 / R 4 + 5 is located usually at the wing base side of this line in O. atlantica sp. nov. (Figs 7 A, 7 B), whilst in O. brevicornis it is usually situated on the line or at the wing tip side (Figs 7 F, 7 G). It is worth noting that similar characteristic was proposed to distinguish between O. arcana Ricarte & Nedeljković, 2022 and O. incisa by RlCARTF et al. (2022). In addition, O. atlantica sp. nov. is on average sturdier than O. brevicornis and has a slightly wider face (but face width is rather variable), the body hue is (especially in fresh specimens) pitch black to dark olive green in O. atlantica sp. nov., whereas the colour of O. brevicornis is more dark grey to grey-blue. The colour of the wing venation is on average darker in O. atlantica sp. nov. All the above indicative characters of females also apply to males. Females of one species belonging to another genus, Lejogaster metallina (Fabricius, 1777), have been found originally partially misidentified as O. brevicornis in one of the very old collections (ŻÓRALsKl 2023), so they can also be confused with females of O. atlantica sp. nov. Despite similar overall appearance, the wing vein M 1 in the females of L. metallina is, however, processive (non-recessive) and their mouthparts are strongly protruding.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA2E946F8CFFEA584741532.taxon	description	Description. Male. Body length 5.6 – 7.0 mm (n = 34; average = 6.3 mm; median = 6.5 mm; holotype = 6.5 mm), black with metallic reflections (Fig. 1 A). Head. Eyes bare. Antennae (Fig. 3 A): scape black; pedicel black with a few white hairs ventrally that are as long as segment width and with a few shorter black hairs dorsally; postpedicel slightly longer than wide (length to width ratio 1.1 – 1.25 ×), slightly angular at tip, bicoloured: overall black but with orange-brown area ventrally near its base. Sensory pit present on outer side. Arista black, twice as long as postpedicel. Face (Fig. 2 A) broad (holotype: upper face width 0.95 mm; lower face width 1.25 mm), slightly wider than half width of head, shiny black, with diverging eye margins. Upper and lateral part of face with wrinkled texture, central part above mouth protrusion with smooth, bare surface. All facial hairs white to yellow, covering part of face, largely missing in central area. Central symmetrical trapezium-shaped area of white pilosity just below antennal sockets connected to triangular areas of white pilosity near eyes. Facial hairs shorter near mouth. Face below antennal sockets in profile (Fig. 2 B) almost straight but varies between individuals from completely straight to slightly convex. Mouth edge in profile protruding far beyond antennal sockets, covered with yellowish to light brown hairs. Frons prominent, shiny, punctuated, covered with yellowish hairs with some hairs in middle black. Vertex shiny, punctuated, with long black-brown hairs bent forward. Ocelli forming equilateral triangle. Occiput with band of white pilosity along eyes. Thorax. Scutum black with metallic, densely punctuated cover. Covered with short erect hairs of equal length, with a few longer hairs. Majority of hairs on scutum black (best seen in posterior view), exceptionally (two specimens from Belgium) all white. Four darker, gold-brown shiny, longitudinal vittae appear where this cover has less dense or absent punctation. Scutellum metallic black, covered with yellowish hairs, with rim along posterior margin and with row of hairs at margin, some slightly bent towards midline, shorter than half length of scutellum. Anterior anepisternum shiny, without hairs, except for very short hairs on its posterior dorsal part. Posterior anepisternum shiny, covered with long hairs, except for its bare anteroventral part. Hair patches on upper and lower katepisternum widely separated. Wings transparent but slightly darkened and completely covered with microtrichia. Venation black. Vein M 1 bent in middle, recessive through location of junction M 1 / R 4 + 5 in wing topology towards wing base, as illustrated on Fig. 7 A; varying between individuals as on Figs 7 C – E. Pterostigma light brown with dark brown basal area. Halteres yellow-grey. Legs. All legs shiny metallic black. Femora slightly swollen, two times maximum width of tibia. Tibia covered with short adpressed white hairs, fore and mid femora covered with upstanding longer whitish hairs on posterior side, longest hairs on posteroventral side, some more than 3 / 4 of femora width. Hind femora with short hairs, less than half femur width. Ventral side of hind femora covered with short adpressed black bristles. Ventral side of all tarsomeres of middle legs covered with short adpressed black bristles. First tarsomeres of middle legs with four longitudinal rows of these bristles, inner rows located close to each other. Middle tibiae with some black bristles at top. Claws orange at base, black at tip. Abdomen oval, black. Dull and lightly pollinose in central areas, shiny olive-golden metallic on sides of all tergites. Dull area on tergite IV forms triangular (rarely slightly trapezoid), backwards directed vitta, covering around 50 % of tergite. Shiny parts of tergites covered with white adpressed hair, directed towards sides of tergites. Dull central area covered with shorter and much sparser hairs. Sternites covered with white hairs: sternite I shiny with sparse hairs restricted to median part; sternite II with erect and long hairs; sternites III and IV with shorter and inclined hairs, pointing backwards or to centre of sternite. Terminalia. Surstylus very wide in basal half with broadest section in middle part and with top abruptly narrowing into curved tip (Figs 5 A – C). Posteroventral process of surstyli rudimentary (Fig. 5 B). Phallus, in anterior view (Fig. 5 C), shaped as broad cylindrical, concave cavity. In lateral view (Fig. 5 A), with rather long, slender anterodorsal hook-shaped appendix and small anteroventral appendix. Beneath these third delicate, long, recurving, bristle-like process of phallus, extending far outside genital capsule from beyond anteroventral edge of postgonites. Postgonites with quadrate tip posterodorsally, extending beyond tip of phallus. Each postgonite with small denticle on its anterior edge and with single strong seta beneath. Hook-shaped anteroventral extension of postgonite, found in O. brevicornis, is missing (Fig. 5 B). Female. Body length 5.9 – 7.0 mm (n = 12; average = 6.6 mm; median = 6.6 mm). Resembling male (Fig. 1 B) except for the following: eyes dichoptic; frons with five (sometime six) deep and distinct lateral furrows, abdomen broader, face in lateral view more concave, hairs on scutum all white to light brown (no black hairs) and hairs on vertex pale (single black might appear). Tergite V with shallowly curved posterior margin and without keel or incision in middle. The same variability in wing topology and postpedicel length to width ratio as reported for males. Biology and behaviour. Males of this species have been observed sitting next to water-filled tracks in deciduous forest with wood and leaf debris and along the muddy margins of small forest streams. Most individuals from Poland (locus typicus) were caught on a solitary hawthorn shrub close to a spring-fed marshy area with alder carr and in direct vicinity of small streams with clean and cold water. Elsewhere, this species is found mostly close to small and shaded rivulets in deciduous forest, or in deciduous forests with seepages. In Southern Europe it becomes increasingly montane (up to 1720 m a. s. l.), though less so in areas with high rainfall.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA2E946F8CFFEA584741532.taxon	etymology	Etymology. From the Latin atlanticus, meaning “ of or near the Atlantic Ocean ”, referring to the main compact biogeographical region of occurrence of this species in Europe, as opposed to the similar O. brevicornis that is nearly absent in these areas.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA2E946F8CFFEA584741532.taxon	distribution	Distribution. Species with a mainly Atlantic distribution (Fig. 8) with its strongholds along the Central European Atlantic coast and in Great Britain, extending east to the Baltic coast and south-west parts of Poland, and south into the Iberian Peninsula. Scarcer and more isolated records appear out of the Atlantic zone. The range of O. atlantica sp. nov. is very similar to the range of two other Brachyopini species, i. e., Melanogaster hirtella (Loew, 1843) and Chrysogaster virescens Loew, 1854, also explicitly referred to or presented as “ Atlantic ” species (SPFlGHT 2017). Molecular data. A total of 16 specimens of O. atlantica sp. nov. from Belgium, Poland and Spain were successfully sequenced for this study. Additionally, we downloaded another sequence from BOLD and two more sequences from GBOL belonging to specimens previously identified as O. brevicornis coming from England and Germany, respectively. In our NJ tree we recover all sequences of O. atlantica sp. nov. and O. brevicornis together, forming a cluster with high support (BS = 100 %). All sequences of our new species cluster together with high support (BS = 100 %), except for one Belgian specimen (GenBank accession number OR 859705) and a Spanish individual (PP 214180) (Fig. 10). The COI sequences of O. atlantica sp. nov. show an uncorrected intraspecific pairwise distance between 0.0 and 0.014 (or a difference between 0.0 and 1.4 %). External and genital morphology of the Belgian male from Rossignol (GenBank acc. no. OR 859705) was carefully studied several times and by different people (FM and XM), and we confirm that it belongs to O. atlantica sp. nov .. The terminalia are still attached to the male body (they were extended and rotated, but not detached), assuring that terminalia were not swapped with other individuals. We, thus, exclude the possibility of a morphological misidentification of this individual. During the molecular laboratory steps, in the 96 - well plate where this specimen was included, all its neighbour wells contained either other genera or species, or individuals of O. atlantica sp. nov. This makes a material switch between a specimen of O. brevicornis into the well corresponding to the Belgian male very unlikely. We are confident that there was no error made in the laboratory. A second attempt to re-sequence this Belgian fly failed. The fact that this specimen shares the COI haplotype with another individual of O. brevicornis was not expected, as the differences in external morphology and genitalia are clear and stable, but it is not uncommon in Syrphidae that two different species share the same COI haplotype (see Discussion). Moreover, the placement of the Spanish specimen of O. atlantica sp. nov. from Lugros (GenBank acc. no. PP 214180) in the NJ tree between the two clusters of O. atlantica sp. nov. and O. brevicornis (without high support value), whereas it agrees morphologically completely with the concept of O. atlantica sp. nov., and the low interspecific variability between these two species reinforces the results from our study, so we can conclude that both species cannot be unmistakably characterised using DNA barcodes.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA8E942FBCDFC8A84591031.taxon	description	(Figs 1 C – D, 2 C – D, 3 B, 4 B, 5 D – F, 6 A – C, 7 F – J, 9 B, 9 C)	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA8E942FBCDFC8A84591031.taxon	materials_examined	Type material. NFoTYPF: J (Figs 1 C, 2 C – D, 3 B, 4 B, 6 A, 7 F), labelled: “ Poland XT 19 // Wielkopolski Nat. Park // 52 ° 18 ’ 25 ’’ N 16 ° 40 ’ 14 ’’ E // “ Trzcielińskie Bagno ” // 10 / V / 2006 // P. Trzciński leg. ” and with our red neotype designation label “ NEOTYPE J // Chrystogaster brevicornis Loew, 1843 // design. R. Żóralski & F. Van de Meutter, 2024 ”. Matches type locality and all characters of original description by LoFw (1843), deposited in ZMHB. Additional material studied. Voucher specimens. GERMANY: Frankfurt am Main [“ Frankf. a / M. // Coll. H. Loew // 12930 // Typus (red label) // Orthoneura brevicornis m // NOT A TYPE locality mism. R. Żóralski, 2023 ”], 1 J (Figs 7 H, 9 B, 9 C) (ZMHB, ex coll. H. Loew). POLAND: 1 ♀ (Figs 1 D, 7 G), labelled “ Poland XT 19 // Wielkopolski Nat. Park // 52 ° 18 ’ 25 ’’ N 16 ° 40 ’ 14 ’’ E // “ Trzcielińskie Bagno ” // 10 / V / 2006 // P. Trzciński leg. ” and “ VOUCHER SPECIMEN ♀ // Orthoneura brevicornis (Loew, 1843) // det. R. Żóralski // & F. Van de Meutter, 2024 ”, intentionally designated voucher specimen to unambiguously reflect characters of opposite sex of the neotype, matches all characters of original description of female (LoFw 1857), caught together with neotype, deposited in ZMHB; 2 JJ, bearing our label “ VOUCHER SPECIMEN J // Orthonevra brevicornis (Loew, 1843) // det. R. Żóralski // & F. Van de Meutter, 2024 ”: Jeleń, 4. v. 1986, 1 J (Figs 5 D, 5 E, 5 F, 6 B, 7 I), leg. B. Soszyński (USMB); Mrzezino, near Reda river [CF 35], 29. iv. 2019, 1 J (Fig. 6 C) (GenBank acc. no. OR 859720), leg. RZ (MZPW). GEORGIA: Dviri, 12. v. 2022, 1 J (Fig. 6 J), leg. FM (RBINS). Other specimens. 229 JJ 96 ♀♀. CZECH REPUBLIC: Veltrusy- Obora, deciduous forest, 7. v. 1985, 1 J, leg. Barták (ZFMK). GERMANY: Berlin [= Berlin; Berlin 55949.], 15. v. 1906, 1 ♀ (ZMHB, ex. coll. T. Becker); Berlin [= Berlin; Orth. brevicornis Lw.; det. Oldenberg; Berlin 55949.], 25. v. 1906, 1 ♀ (ZMHB, ex. coll. T. Becker). Berlin, Schildhorn, vi. 1948, 1 ♀ (ZMHB, ex coll. A. Riedel). GREECE: Grevena, 505 m, 40.015 N 21.395 E, 8. v. 2022, 1 J (GenBank acc. no. OR 859727), leg. FM (FMTB). HUNGARY: Hild, date unknown, 1 J, leg. Thalhammer (ZFMK). POLAND: Ślęża Mtn. [= Zobten 12310], 3. v, (ZMHB, ex coll. T. Becker). Niemcza [= Nimpsch Schles. Duda; O. plumbago Lw.], 14. v. 1908, 1 J 1 ♀, 17. v. 1908, 1 ♀, 23. v. 1908, 3 ♀♀, 26. v. 1908, 1 ♀, 13. vi. 1910, 1 ♀, 14. v. 1912, 1 J 1 ♀, (ZMHB, ex coll. O. Duda); Jędrzejów, oddz. 210, 3. v. 1954, 1 ♀, on Padus avium, leg. J. Karczewski (MZPW) (TRoIANo- wA- BAŇKowsKA 1959, BAŇKowsKA 1961, as O. frontalis); Zdziar-Łopatki ad. Staroźreby, alder carr near Płonka river, DD 33, 17. v. 1971, 1 J 2 ♀♀, leg. J. K. Kowalczyk (RZRP); Aleksandrów Łódzki, 1. v. 1973, 1 ♀, leg. B. Soszyński (RZRP); Rogów ad Łódź, 27. v. 1975, 1 J, leg. B. Soszyński (RZRP); Świętokrzyski National Park: Święty Krzyż, 2. vi. 1979, 1 ♀, leg. J. K. Kowalczyk (RZRP) (ŻÓRALsKl et al. 2017); Teofilów, DC 40, 1. v. 1983, 1 ♀, leg. B. Soszyński (RZRP); Spalski Landscape Park: Konewka, DC 41, 19. v. 1985, 1 ♀, leg. B. Soszyński (RZRP), 13. v. 2017, 1 ♀, leg. M. Soszyński (RZRP); Łagiewnicki Forest: Marianka, 4. v. 1995, 1 ♀, leg. B. Soszyński (RZRP); Biebrza National Park: Sztabin, 17. v. 2003, 1 J, leg. Wanat M. (RZRP); Wiry, XT 19, 15. v. 2004, 1 J, leg. P. Trzciński (PTPP); Biebrza National Park: Grobla Honczarowska, 8. vi. 2006, 1 ♀, Malaise trap, leg. J. Sawoniewicz (RZRP); Trzcielińskie Bagno [XT 19], 1. – 10. v. 2008, 192 JJ (GenBank acc. no. OR 859703, OR 859667, OR 859676, OR 859690, OR 859714, OR 859726, OR 859728, OR 859700, OR 859693), 54 ♀♀, Moericke traps (part of it: 125 JJ and 13 ♀♀ continued to be stored in alcohol), leg. P. Trzciński (PTPP, RZRP), 1. – 10. v. 2008, 2 JJ 1 ♀, Moericke traps, leg. P. Trzciński (ZFMK), 1. – 10. v. 2008, 1 J 1 ♀, Moericke traps, leg. P. Trzciński (SBHN), 14. v. 2008, 1 J, leg. P. Trzciński (PTPP), 23. v. 2008, 1 J, leg. P. Trzciński (PTPP), 24. iv. 2010, 5 JJ 4 ♀♀, leg. P. Trzciński (PTPP); Oleśnickie Jodły, CC 64, 24. iv. 2009, 1 ♀, leg. B. Soszyński (RZRP); Kuzki ad Włoszczowa, 3. v. 2012, 1 J, leg. Ł. Mielczarek (LMMP); Spalski Landscape Park: Spała, DC 41, 24. iv. 2015, 1 J, leg. RZ (RZRP) (WlTFK et al. 2015). Spalski Landscape Park: Ceteń, DC 50, 4. iv. 2014, 1 J, leg. M. Soszyński (RZRP), 22. iv. 2014, 1 J, leg. Ł. Mielczarek (LMMP), 27. iv. 2015, 1 ♀, leg. B. Soszyński (RZRP) (WlTFK et al. 2015), 27. iv. 2015, 1 J, leg. RZ (RZRP) (WlTFK et al. 2015), 27. iv. 2015, 1 J 1 ♀, leg. P. Trzciński (PTPP) (WlTFK et al. 2015), 9. v. 2015, 1 ♀, leg. M. Soszyński (RZRP), 25. v. 2015, 1 J, leg. Ł. Mielczarek (LMMP); Suwalski Landscape Park: Sidorówka, 22. v. 2015, 1 ♀, leg. Ł. Mielczarek (LMMP); Karniowce ad Trzebinia, 19. vi. 2015, 1 J, leg. Ł. Mielczarek (LMMP); Krynica Morska, 7. v. 2016, 1 J, leg. Ł. Mielczarek (LMMP); Nowa Wieś near Maniówka river, 24. v. 2016, 1 ♀, leg. RZ (RZRP) (ŻÓRALsKl et al. 2016); Wiatrołuża III, peatbog, 24. v. 2016, 1 J, leg. Ł. Mielczarek (LMMP) (ŻÓRALsKl et al. 2016); Gdańsk-Oliwa: Kwietna Street near the Oliva stream, 1. vi. 2016, 1 ♀, leg. RZ (RZRP); Gibała near Drwęca river, 13. v. 2017, 1 J, leg. RZ (RZRP); Zaskalskie-Bodnarówka, 24. vi. 2017, 1 ♀, leg. Ł. Mielczarek (LMMP); Lisówki ad Stęszew, XT 19, 22. v. 2018, 1 J, leg. P. Trzciński (PTPP); Szumny Zdrój ad Górzno, DD 19, 27. iv. 2019, 1 J, leg. Ł. Mielczarek (LMMP); Gdynia-Leszczynki near Chylonka stream, 14. v. 2019, 1 ♀, leg. RZ (RZRP); Włoszczowa “ klekot ”, vi. 2019, 2 ♀♀, Malaise trap, leg. Ł. Mielczarek (LMMP); Kartoszyno, CF 16, 30. v. 2021, 1 J (GenBank acc. no. OR 859651), on Crataegus sp., leg. RZ (RZRP), 24. vi. 2023, 2 ♀♀ (GenBank acc. no. OR 859686), leg. RZ (RZRP); Zakrzewska Osada, XV 61, 20. vi. 2022, 1 ♀, leg. & coll. D. Tarnawski. GEORGIA: Dviri, 10. v. 2022, 1 J, leg. FM (FMTB); Dviri, 12. v. 2023, 2 JJ 1 ♀, leg. W. Opdekamp (WORB). SWITZERLAND: Chevroux, 8. – 15. v. 2020 (Malaise trap), 1 J, leg. Association de la Grande Cariçaie, Nina Perret-Gentil (MZLS).	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA8E942FBCDFC8A84591031.taxon	diagnosis	Diagnosis. See notes on O. brevicornis within diagnosis of O. atlantica.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA8E942FBCDFC8A84591031.taxon	description	Redescription. Male. Body length 5.0 – 6.4 mm (n = 45; average = 5.9 mm; median = 5.9 mm; neotype = 5.9 mm), overall black to grey (Fig. 1 C). Head. Eyes bare. Antennae (Fig. 3 B): scape black; pedicel dark-brown with a few white hairs ventrally that are as long as segment width and with a few shorter black hairs dorsally; postpedicel slightly longer than wide (length to width ratio 1.1 – 1.3 ×), not angular at tip, bicoloured: basoventral orange area extending over more than half of postpedicel and rest dark-brown. Sensory pit present on outer side. Arista brown, twice as long as postpedicel. Face (Fig. 2 C) in most cases relatively narrow (neotype: upper face width 0.75 mm, lower face width 1 mm), less than half width of head, dull grey with diverging eye margins. Face with wrinkled texture, central part above mouth protrusion often with small, bare surface. Central symmetrical trapezoid area of dense white pilosity just below antennal sockets connected to triangular areas of white pilosity near eyes. All facial hairs white to yellow, covering part of face, largely missing in central area. Facial hairs shorter near mouth. In side view (Fig. 2 D), facial profile slightly convex in middle, but varies between individuals between slightly convex to straight. Mouth edge protruding only slightly beyond antennal sockets. Frons not prominent, dull grey, punctuated, covered with white to yellowish hairs. Vertex dull grey, punctuated, with long yellowish hairs slightly bent forward. Ocelli forming almost equilateral triangle. Occiput with band of white pilosity along eyes. Thorax. Scutum dull grey with metallic, densely punctuated cover. Covered with short erect hairs of equal length. All hairs on scutum white, exceptionally (two specimens from Georgia) with a few black hairs. Four darker longitudinal vittae where this cover is less dense or punctation is absent, best visible from anterodorsal side. Scutellum dull grey and slightly lighter than scutum, covered with white hairs, with rim on its posterior margin and with row of hairs along its hind rim, some slightly bent towards midline, shorter than half length of scutellum. Anterior anepisternum shiny, without hairs, except for very short pilosity on its posterior dorsal part. Posterior anepisternum shiny, covered with long hairs, except for its bare anteroventral part. Hair patches on upper and lower katepisternum widely separated. Wings transparent and with microtrichia all over; rarely with brown cloud in centre. Venation between dark brown and black, but not pitch black. Vein M 1 with its anterior end almost perpendicular to R 4 + 5, non-recessive because of location of junction M 1 / R 4 + 5 in wing topology as illustrated on Fig. 7 F; much varying between individuals as on Figs 7 H – J. In almost all cases, if line is drawn between vein junctions M 1 / M 2 and C / R 2 + 3, then junction M 1 / R 4 + 5 is located very close to it, usually a bit to wing tip (Figs 7 F, 7 G), but never much to wing base as it is the case in O. atlantica sp. nov. (Figs 7 A, 7 B). Rarely crossvein M 1 more deeply curved (Fig. 7 I) or even wavy, according to the observed rule that the narrower wing cell r 4 + 5 is, the more bent vein M 1 is. Very rarely specimens have extra drop swelling on vein M 1 on one or two wings, or extra denticles on vein M 2 on two wings. Pterostigma light brown with brown anterior margin. Halteres yellow-grey. Legs. All legs black, usually with shade of grey. Femora slightly swollen, two times maximum tibia width. Tibia covered with short adpressed white hairs, fore and mid femora covered with upstanding longer whitish hairs on the posterior side, longest hairs on posteroventral side (some more than 3 / 4 th of the width of the femora), hind femora with short hairs (less than half femur width). Ventral side of hind femora and ventral side of all tarsomeres of middle legs covered with short adpressed black bristles. First tarsomeres of middle legs with four longitudinal rows of these bristles, inner rows located close to each other. Claws orange at base, black on top. Abdomen oval, grey. Dull and lightly pollinose in central areas, shiny grey metallic on sides of all tergites. Shiny parts of tergites covered with white erect or adpressed hairs, mostly directed towards posterior edge of tergites. Dull central area covered with shorter and much sparser hairs. Sternites covered with white hairs: sternite I shiny with sparse hairs, but lateral parts hairless; sternite II with erect and long hairs; sternites III and IV with shorter and inclined hairs, pointing backwards or to centre of sternite. Terminalia. Phallus, in anterior view (Fig. 5 F) laterally flattened. In lateral view (Figs 5 D, 6 A – C), with relatively short and broad anterodorsal hook-shaped appendix and prominent flat anteroventral appendix. Some individual variation in shape of flat anteroventral appendix of phallus was observed, as illustrated on Fig. 6. Delicate, long and bristle-like process of phallus present. Postgonites not extending beyond tip of phallus, with visible hook-shaped extension anteroventrally (Fig. 5 E), and without small denticle on anterior edge found in O. atlantica sp. nov. Posteroventral process of surstyli present (Fig. 5 E). Female. Body length 5.2 – 6.8 mm (n = 23; average = 6.2 mm; median = 6.3 mm). Resembling male (Fig. 1 D), except for the following: eyes dichoptic; frons with 5 lateral furrows, abdomen larger, face in lateral view more concave. Tergite V with shallowly curved posterior margin and without keel or incision in middle. The same variation in wing topology and postpedicel length / width ratio as reported for males is observed in females.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA8E942FBCDFC8A84591031.taxon	biology_ecology	Biology and behaviour. Adults have been found sitting on vegetation near marshland or feeding on flowers with a preference for shrubs and trees (maples Acer spp., willows Salix spp., rowans Sorbus spp.) but also on low flowers. The area where this species occurs in very large numbers near Poznań (locus typicus) is the “ Trzcielińskie Bagno ” [= Trzcielińskie Marsh], a protected area within the Wielkopolska National Park, where many species of Stratiomyidae were also found (TRZClŇsKl 2007), including Actina chalybea Meigen, 1804 in its north edge of the range, and endangered Stratiomys cenisia Meigen, 1822, Oxycera nigricornis Olivier, 1822 and O. trilineata (Linnaeus, 1767). The swamp is a remnant of a former post-glacial lake fed by the waters of the small river Samica Stęszewska, surrounded by a thicket of willows and reeds, and the floodplain of the river has a variable water level, probably creating favourable conditions for the development of the larvae. Over 250 adults of both sexes of O. brevicornis were collected there using Moericke traps in hard-to-reach thickets of flowering willows in the first days of May 2008, and this species was dominant in Syrphidae material. Other findings, documented in the material section, are generally sporadic and associated with the immediate proximity of wetlands.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
03A07F56FFA8E942FBCDFC8A84591031.taxon	distribution	Distribution. Mainly distributed over Central and Eastern Europe (Fig. 8) and further east into Russia and Transcaucasia. Most records come from Poland (locus typicus) but the species is also confirmed from eastern Germany, Ukraine (Fig. 21 in PRoKHoRov et al. 2023 shows the typical male terminalia), Russia (Fig. 12 in STACKFLBFRG 1953 shows the typical male terminalia; present in European parts of Russia and western Siberia), the Czech Republic, Hungary, northern Greece, the Republic of Georgia and few, isolated locations in Western Europe: in the Netherlands and Switzerland. Unverified records of O. brevicornis sensu lato that would fit into the known distribution come from Romania (BRǍDFsCU 1991), Turkey (TÓTH 2013) and Austria (HFlMBURG et al. 2022). Reports of O. brevicornis from Iran (SHAKFRYARl et al. 2012) and Morocco (SAHlB et al. 2020) belong to different species, and the presence of O. brevicornis in these countries needs reassessment. Previous reports of the species from Japan were extensively commented on by ICHlGF (2006) as referring to another species; the slender surstyli and highly asymmetric postgonites in male, as well as the deep incision in the 5 th sternite in female, as described and shown for O. brevicornis in OHlsHl (2011), are clearly not conspecific with O. brevicornis, but close to O. incisa. Molecular data. We were successful in sequencing 14 specimens of O. brevicornis from Poland, Georgia and Greece. In our NJ tree all DNA barcodes of O. brevicornis cluster with sequences of O. atlantica sp. nov. with high support (BS = 100 %), but there is no support for grouping sequences of O. brevicornis alone (Fig. 10). The COI sequences of O. brevicornis have an uncorrected intraspecific pairwise distance between 0.0 and 0.0035 (or a difference between 0.0 and 0.35 %). Notes on types. LoFw (1843) described the species Chrysogaster brevicornis based on two male specimens from Posen [= Poznań] in Poland (LoFw 1843, PFCK 1988). The original type locality was specified based on two independent statements in the Loew’s publication: “ Professor Dr. H. Loew in Posen. (...) Ich besitze von dieser Art zwei ganz übereinstimmende hier gefangene Männchen [= I have two identical males of this species caught here.] ” Further in the paper, after expanding on the species Chrysogaster nobilis Fall., Chrysogaster plumbago Loew and Chrysogaster brevicornis nov. sp., and before describing Chrysogaster frontalis nov. sp. and Chrysogaster fumipennis nov. sp., he wrote: “ Zu den bereits beschriebenen drei schwarzbeinigen Arten der zweiten Abtheilung von Chrysogaster, die in der Umgegend Posens vorkommen, treten nur noch zwei, dem südlichen Europa und benachbarten Kleinasien angehörige Arten hinzu, (...) [= To the three black-legged species of the second chapter of Chrysogaster already described, that occur in the vicinity of Poznań, two other species are added now, occurring in southern Europe and neighbouring Asia Minor, (...).] ” Only one specimen of O. brevicornis of the collection of Hermann Loew was logged into the ZMHB register book of accessions (Fig. 9 D) to the collection from 1858 – 1884 (under registration no. 12930). This specimen is still present (Figs 9 B, 9 C). Loew’s first handwritten label under the specimen reads “ Frank. a / M ” [= Frankfurt am Main], a German city located 630 km west from the type locality. Loew’s second handwritten label reads “ Orthoneura brevicornis m. ”, with “ m. ” meaning “ mihi ” or “ mein ”, to explicitly indicate the species was described by himself, as in LoFw (1857). Note that Loew uses “ Orthoneura ” instead of the original “ Chrysogaster ” as the genus name. The name Orthoneura (wrong spelling of Orthonevra Macquart) became widely accepted by authors only after the publications of WALKFR (1851) and RoNDANl (1857) and became finally also accepted by LoFw (1857) but was not used by LoFw (1843) when describing Chrysogaster brevicornis. In conclusion, both the location and deduced timing of this specimen do not match with the type series. The specimen clearly comes from Loew’s collection, but it is not one of the two original syntypes. Below the two above-mentioned labels is a red label with “ Type ” typed on it. ZlFGLFR et al. (2020) clarify that specimens of the Loew collection only have two original handwritten labels and that all other labels were added later by museum workers. In this case, the specimen was clearly misinterpreted as a syntype and the type indication is false. Article 72.4 of the Code explicitly allows to take any evidence into account, published or unpublished, when determining which specimens belong to the type series. In this case the documented doubts, especially the mismatch in locality, do not allow designation of the mentioned specimen as the lectotype according to the Article 74.5 of the ICZN (1999). Type material of O. brevicornis was actively searched for by authors. Careful analysis of the collections of ZMHB (main collection and all supplementary drawers) and MZPW did not result in finding Loew’s specimens that could be considered syntypes. Thus, the type series is considered lost or destroyed, and a neotype male specimen from a locality close to the original type locality (Poland, close vicinity of Posen) is hereby designated for the purpose of stabilisation of the taxonomic nomenclature and for stabilisation of the type locality of a nominal taxon. It must be noted, that the terminalia of Loew’s specimen (from Frankfurt am Main, the one rejected to be a syntype) were extracted and examined by the first author in 2023 and is the same as the terminalia of the neotype being here designated. The shape of the terminalia is also consistent with the drawing of the terminalia of O. brevicornis published by STACKFLBFRG (1953, 1970) and further reproduced by other authors: VAN DFR GooT (1981), BRǍDFsCU (1991), and ICHlGF (2006). A female was described by LoFw (1857) under the name Orthoneura brevicornis based on an unspecified number of specimens from Meseritz [= Międzyrzecz] (Poland) with Loew making a note that he also had specimens collected in Florence (Italy) in his collection. None of these female specimens were donated by H. Loew to the ZMHB, nor are present elsewhere to our knowledge. Female specimen (s) used for the description are considered lost or destroyed. A voucher female specimen caught together with the neotype and matching the original description will be deposited in a well-curated accessible collection (ZMHB) together with the neotype.	en	Żóralski, Robert, Meutter, Frank Van De, Mengual, Ximo, Gadawski, Piotr (2024): Two Palaearctic species of Orthonevra (Diptera: Syrphidae) under the name O. brevicornis. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (1): 223-242, DOI: 10.37520/aemnp.2024.015, URL: https://doi.org/10.37520/aemnp.2024.015
