Eutomostethus ephippium (Panzer, 1797) Tenthredo ephippium Panzer, 1797: 52:5. ♀. Syntypes. Type locality: Germany [according to title of the publication]. Tomostethus ephippium var. nigrans Konow, 1887a: 275. Sex not stated. Syntypes. Type locality not stated. Eutomostethus nigrans (Konow, 1887): Liston et al. (2006) Eutomostethus nigrans Blank & Taeger, 1998: 161-162. ♀. Holotype and paratypes. Type locality: Germany, Brandenburg, Luisenfelde, Langer Berg [Grumsiner Forst near Groß Ziethen]. SDEI. Synonymy with E. nigrans Konow by Liston et al. (2006). Notes. COI barcodes of a few specimens identified as E. nigrans are indistinguishable from those of a large number of E. ephippium (red-marked females). Vikberg et al. (2011) discussed the distribution of the two forms in Fennoscandia and more widely in Europe, noting that the patterns of occurrence are complex, and that they are regionally often sympatric, but that the dark form becomes more common towards the West, suggesting that climatic causes may play a role in maintaining this polymorphism. No other differences have been detected between the red-marked and black forms. We therefore revert to treating them as conspecific colour forms.

{"references": ["Liston, AD, Taeger, A, Blank, SM, 2006. Comments on European Sawflies (Hymenoptera: Symphyta). In: Blank, SM, Schmidt, S, Taeger, A, Eds., Recent Sawfly Research: Synthesis and Prospects. Goecke and Evers, Keltern: 245 - 263", "Vikberg, V, Vardal, H, Lonnve, OJ, 2011. The occurrence of Eutomostethus ephippium (Panzer) and E. nigrans (Konow) (Hymenoptera: Symphyta: Tenthredinidae) in Northern Europe. Sahlbergia 17 (1): 56 - 78"]}

Published as part of Liston, Andrew, Mutanen, Marko, Heidemaa, Mikk, Blank, Stephan M., Kiljunen, Niina, Taeger, Andreas, Viitasaari, Matti, Vikberg, Veli, Wutke, Saskia & Prous, Marko, 2022, Taxonomy and nomenclature of some Fennoscandian Sawflies, with descriptions of two new species (Hymenoptera, Symphyta), pp. 151-218 in Deutsche Entomologische Zeitschrift 69 (2) on page 151, DOI: 10.3897/dez.69.84080