Nematus umbratus Thomson, 1871

Prous, Marko, Liston, Andrew, Monckton, Spencer K., Kramp, Katja, Vårdal, Hege, Vikberg, Veli, Heibo, Erik & Mutanen, Marko, 2025, West Palaearctic species of Euura Newman, 1837 (Hymenoptera, Tenthredinidae), European Journal of Taxonomy 977, pp. 1-377 : 243-244

335 Nematus umbratus Thomson, 1871

Nematus breviusculus Eversmann, 1847: 17 . Nomen oblitum. Lectotype designated below. Was

incorrectly synonymised with Euura melanocephalus ( Hartig, 1837) by Prous et al. (2017). Syn. nov. Nematus umbratus Thomson, 1871: 142–143 . Nomen protectum. Lectotype designated 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 umbratus as 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 breviusculus has not been used as valid since 1899. Examples of use of umbratus or umbrata as 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 holmgreni figured 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 holotype is 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. umbratus and E. pohjola are 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. Eversmann leg.; ZIN, DEI-GISHym30032 .

Lectotype Nematus umbratus

SWEDEN • ♀; Lapponia Media [ central Lapland ]; 25 Jul.; C.H. Boheman leg.; MZLU, MZLU2017310 .

Holotype Pteronidea holmgreni

SWEDEN – Torne Lappmark • ♂; Torneträsk; 68.22° N, 19.74° E; 400 m a.s.l.; R. Malaise leg.; NHRS, NHRS-HEVA000004010 .

Notes

The paratype female belongs to E. leptostigma .