Chrysis ardens Coquebert 1801: 59. Holotype ♀; France: Burdigala [= Bordeaux] (MNHN?).
Hedycrum [!] minutum Lepeletier de Saint Fargeau 1806: 122. Lectotype ♀ (designated by Kimsey 1986: 108); France: Soissons (MNHN) (examined). Thomson 1870: 105.
Chrysis integra Dahlbom 1829: 17, nom. praeocc., nec Fabricius, 1787. Syntypes ♂♂, ♀♀; Sweden: Ostro- & Westrogothia [= Öster- & Västergötland] (ZMUL), new synonym. Dahlbom 1831: 35 (as C. integra var. a. & b.), Zetterstedt 1840: 434 [part.], Nylander 1859a: 111 [part.], Thomson 1862: 297 [part.].
Hedychrum integrum [nec (Fabricius, 1787)]: Dahlbom 1845: 3, Westerlund 1893: 30.
Hedychrum ardens: Borries 1891: 93.
Elampus ardeus [!]: Sahlberg 1910: 98.
Holopyga ardens: Aurivillius 1911: 7.
Hedychridium ardens: Lundblad 1913: 213, Hellén 1920: 209, Jansson 1922: 33, Bischoff 1925: 306, Trautmann 1927: 68, Krogerus 1932: 124, Jansson 1934: 287, Hellén 1935: 8, Fahlander 1954: 254, Valkeila 1962: 64, Faester 1965: 189, Tumšs & Maršakovs 1970: 91, Lomholdt 1972: 119, Erlandsson 1971: 88, Janzon 1983: 171, Nilsson 1986: 86, Vikberg 1986b: 68, Hedström 1989: 154, Hellqvist 1994: 33, Strumia & Berg 1995: 64, Hellqvist & Petterson 1997: 51, Nilsson et al. 1999: 5, Bergsten et al. 2000: 6, Sörensson 2000: 23, Berglind 2003: 13, Söderman & Vikberg 2003: 44, Abenius 2004 b: 40, Abenius & Larsson 2004, Soon 2004: 18, 44, Abenius & Larsson 2005, Bergsten et al. 2005: 14, Hallin 2005, Abenius 2006: 57, Hallin 2006: 11, Hansen et al. 2006: 302, Hellqvist 2006: 37, Abenius & Hellqvist 2007: 66, Hallin 2007: 21, Kalniņš et al. 2007: 142, Salminen 2007: 143, Valtonen 2007: 20, Karlsson 2008, Abenius 2009: 59, Franzén & Norén 2009: 40, Hallin 2009: 10, Johansson 2009, Allearter.dk 2010, Artsdatabanken 2010, Fritz & Larsson 2010: 151, Johansson 2010: 118, Orlovskytė et al. 2010: 146, Smissen 2010d: 393, Ivarsson 2011: 43, Larsson 2011: 29, Molander 2011: 95, Ødegaard et al. 2011: 64, Hallin 2012, Larsson 2012: 13, Ranta 2012: 33, Rosa & Soon 2012, Dyntaxa 2013, Johansson 2013a: 81, Johansson, in press.
Hedychridium ardens var. viridis Trautmann & Trautmann 1919: 31. Type?; Germany: Fürth (ZMB). Forsius 1925: 183, Trautmann 1927: 68.
Distribution. Denmark, Estonia, Finland, Latvia, Lithuania, Norway, Sweden, Russian Fennoscandia.—Transpalearctic: Europe, North Africa, Middle East, Mongolia, Russian Far East (Kimsey & Bohart 1991, Linsenmaier 1997, Kurzenko & Lelej 2007).
Remarks. The species is common in all Nordic and Baltic countries. In Norway, many specimens have been erroneously placed under the genus Holopyga in collections, and therefore the species has been wrongly considered as rare in the country. The northernmost records are from southern Finnish Lapland (Obb: Rovaniemi).
Dahlbom (1829) reported the species from Sweden initially with the name Chrysis integra. Although he attributed the authorship of the species to Fabricius, his description differs significantly from that of Fabricius (1793: 241), and they cannot be regarded as referring to the same species. Fabricius, for example, stated that the species resembles C. ignita in its shape (" Statura et summa affinitas C. ignitae "), whereas according to Dahlbom it resembles C. aurata (= Pseudomalus auratus) in its shape (" Statura Chr. aurata at paullo minor "). Apparently, Dahlbom had seen only Fabricius’ later shorter description of the species, published in 1804, which does not include information on e.g. the body shape. Later (1831), Dahlbom treated C. integra as three varieties (a, b and c), of which var. a referred to his original description of the species, and var. b and var. c represented new forms. Var. b can be seen as a green form of H. ardens, while var. c corresponds with the current interpretation of H. cupreum.
In 1845 Dahlbom transferred C. integra to the genus Hedychrum (as H. integrum) and described var. c as a new species, H. cupreum. Additionally, he reported H. ardens as a distinct species, closely related to H. integrum and rare in Europe. In 1854, Dahlbom found out that his earlier interpretation of integrum was a synonym of H. minutum Lepeletier de Saint Fargeau (= H. ardens), but erroneously proposed the name integrum as a replacement name for cupreum, considering cupreum to be a homonym of cupratum Klug. Dahlbom also wrongly considered ardens to be a synonym of lucidulum Fabricius (= Hedychrum nobile). As Dahlbom’s description of C. integra (= Hedychrum integrum of 1845) is valid (nec Fabricius, 1793) and corresponds with the current interpretation of H. ardens, the nominal species Chrysis integra Dahlbom, 1829 should be considered a new synonym of H. ardens.