Nematus breviusculus Eversmann, 1847: 17 Euura melanocephalus ( Hartig, 1837 ) Nematus umbratus Thomson, 1871: 142–143 Pteronidea holmgreni Lindqvist, 1968: 192 West Palaearctic species of Euura Newman, 1837 (Hymenoptera, Tenthredinidae) Prous, Marko Liston, Andrew Monckton, Spencer K. Kramp, Katja Vårdal, Hege Vikberg, Veli Heibo, Erik Mutanen, Marko European Journal of Taxonomy 2025 2025-02-27 977 1 377 Thomson, 1871 Thomson 1871 [609,1031,1401,1428] Insecta Tenthredinidae Nematus Animalia Hymenoptera 242 243 Arthropoda species umbratus       Nematus breviusculus Eversmann, 1847: 17. Nomen oblitum. Lectotypedesignated below. Was incorrectly synonymised with  Euura melanocephalus( Hartig, 1837)by Prous et al. (2017). Syn. nov.   Nematus umbratus Thomson, 1871: 142–143. Nomen protectum. Lectotypedesignated by Prous et al.(2019).     Pteronidea holmgreni Lindqvist, 1968: 192. Synonymy by Liston et al. (2023).  In accordance with Article 23.9.1 of the International Code of Zoological Nomenclature ( ICZN 1999), we retain the junior name  umbratusas valid, because it has been used more than 25 times by at least ten authors as the valid name for this taxon during the last 50 years, whereas  breviusculushas not been used as valid since 1899. Examples of use of  umbratusor umbrataas the valid name for this taxon during the last fifty years: Hellén 1976; Smith 1979; Verzhutskii 1981; Kangas 1985; Viitasaari & Vikberg 1985; Zhelochovtsev 1988; Liston 1995, 1997; Zhelochovtsev & Zinovjev 1995; Taeger et al. 1998, 2006, 2010; Lacourt 1999, 2020; Pschorn-Walcher & Altenhofer 2000; Haris 2001; Liston et al. 2006; Roller & Haris 2008; Schedl 2009; Prous et al. 2014, 2017, 2021; Macek & Kula 2014; Chevin & Savina 2016; Sundukov 2017b; Macek et al. 2020; Liston et al. 2023    Diagnosis (male) The penis valve of  holmgrenifigured in the original description ( Lindqvist 1968: 195, fig. 11) appears to be taken from an earlier publication under the name  Nematus( Pteronidea)sp. ( Lindqvist 1967a: 20, fig. 14), which fits better with the penis valve of  Euura pohjola. The actual penis valve of the  holmgreni holotypeis not different from the penis valve of  Nematus umbratus, which indeed is rather similar to that of  Euura pohjola. Differences between the penis valves of  N. umbratusand  E. pohjolaare as follows: a Ventroapical lobe of paravalva extending about one third of the length of valvispina so that the apical margin of paravalva appears less oblique or even roughly perpendicular relative to the valvispina b Basal third or half of valvar strut more or less at the ventral margin of paravalva c Dorsobasal part of paravalva narrowing more abruptly .....................................  Nematus umbratus aa Ventroapical lobe of paravalva extending about half of the length of valvispina so that the apical margin of paravalva appears more oblique relative to the valvispina bb Valvar strut distinctly removed from ventral margin of paravalva cc Dorsobasal part of paravalva narrowing more gradually ...........................................  Euura pohjola    Type material examined   Lectotype  Nematus breviusculus, here designated   RUSSIA– Tatarstan• Gynandromorph; Kasan Province; 55.8° N, 49.1° E; 8 Jul.; E. Eversmannleg.; ZIN, DEI-GISHym30032.   Lectotype  Nematus umbratus   SWEDEN• ♀; Lapponia Media[ central Lapland]; 25 Jul.; C.H. Bohemanleg.; MZLU, MZLU2017310.   Holotype  Pteronidea holmgreni   SWEDEN–  Torne Lappmark• ♂; Torneträsk; 68.22° N, 19.74° E;  400 ma.s.l.; R. Malaiseleg.; NHRS, NHRS-HEVA000004010.   Notes The paratypefemale belongs to  E. leptostigma. 5085095389 ZIN Jul. & E. Eversmann Russia 55.8 Kasan Province 6372 49.1 Gynandromorph 243 244 DEI-GISHym30032 1 Tatarstan lectotype 5085095621 [189,1399,1112,1139] MZLU C. H. Boheman Sweden Lapponia Media 243 244 MZLU2017310 1 1 lectotype 5085095705 NHRS R. Malaise Sweden 400 68.22 Torne Lappmark 592 19.74 Tornetrask 243 244 NHRS-HEVA000004010 1 1 holotype