Euura sempersolis
Creators: name: Prous, Marko
name: Liston, Andrew
name: Monckton, Spencer K.
name: Kramp, Katja
name: Vårdal, Hege
name: Vikberg, Veli
name: Heibo, Erik
name: Mutanen, Marko
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Tenthredinidae
Euura
Euura sempersolis

description: 205 Euura sempersolis (Kiaer, 1898)
Figs 232, 456
Amauronematus sempersolis Kiaer, 1898: 41–42. Lectotype designated below.
Amauronematus tristis Lindqvist, 1959d: 9–10. Synonymy by Hellén (1970).
Diagnosis
Nearly completely black, brown or pale pterostigma, “ Amauronematus - type ” head, bifid claws, valvula 3 short and somewhat triangular. Most similar species are dark specimens of the tillbergi group and E. hebes, from which it can be distinguished by the structure of the saw (serrulae basally with small but distinct protrusion and with large space between serrulae). Additionally, valvula 3 does not have a distinct invagination (present in E. hebes). Males possibly not clearly distinguishable from other aegra group species.
Type material examined
Lectotype Amauronematus sempersolis, here designated
NORWAY – Finnmark • ♀; Sør-Varanger, Strand; 69.524° N, 29.978° E; Jun. 1892; S. Schneider leg.; MZH, http://id.luomus.fi/GL.5237.
Holotype Amauronematus tristis
FINLAND – Kittilä Lapland • ♀; Muonio, Pallastunturi; 68.100° N, 23.999° E; 22 Jun. 1942; W. Hellén leg.; MZH, http://id.luomus.fi/GL.2759.
Notes
Kiaer (1898) wrote that he described Amauronematus sempersolis from a syntype series of four individuals of both sexes collected by Sparre Schneider in Sydvaranger, northern Norway, in June 1892. Lindqvist (1959d) discussed five (!) presumed syntype specimens (4 females, 1 male) of A. sempersolis borrowed from Tromsø Museum. He wrote that they belonged to four different taxa and that none of them agreed with Kiaer’s description, except possibly the male, which he identified as belonging to the Euura histrio species group, and that therefore the females could not be syntypes. He did not designate a lectotype, and concluded by stating that he was unable to identify Kiaer’s species from the description. All these specimens had apparently been previously examined by O. Conde in 1939, according to corresponding determination labels (Lindqvist 1959d). Lindqvist (1973) again discussed the potential syntypes of A. sempersolis, but this time in the light of an additional female specimen which at that time was in the collection of W. Hellén. This is almost certainly the specimen currently in the FMNH collection, designated above as lectotype, because both Hellén (1970) and Lindqvist (1973) cite different parts of the determination label (http://id.luomus.fi/ GL.5237) written by O. Conde in 1939. Hellén also mentioned that the specimen is labelled “Strand 1892”. Note that “Strand” certainly refers to the collection locality, not to Embrik Strand, the well-known Norwegian naturalist.
Although the specimen now designated as lectotype was already labelled as such by an unknown person, there is no unequivocally valid previously published designation. Hellén (1970), referred to this specimen as [translated from German] “the female specimen (Strand 1892) marked as ‘type’ by Conde”, but did not make clear whether the male syntype had also been labelled by Conde as a type. Lindqvist (1973) ended his text on A. sempersolis with the commentary [translated]: “As regards the type selected by Conde, which in his opinion should be identical to hebes, one must emphasise that this specimen does not represent the true hebes, but A. tristis described by me (1959d: 9). The sawsheath of this species [tristis] and the matt mesopleura agree with Kiaer’s description, whereas the labrum and the tegulae are always completely black, which differs from the sempersolis description. The type selected by Conde and identified as hebes can accordingly not be accepted as [belonging to the syntype series of] sempersolis ”. Thus, Lindqvist’s comments cannot be regarded as a lectotype designation.
It seems that Conde and Lindqvist were correct in regarding the type series of A. sempersolis as consisting of more than one species, but we disagree with the opinion of Lindqvist (1973), that the female now designated as lectotype significantly differs from Kiaer’s description in two colour characters, and is therefore not part of the syntype series. Firstly, the labrum of the A. sempersolis lectotype is indeed markedly paler than the rest of the head, but the labrum of A. tristis is not “always black” as claimed by Lindqvist (1973). We have examined many specimens with a more or less pale labrum, and Lindqvist (1959d) himself even noted such colouration in his description of A. tristis [translated from German]: “Labrum [..] occasionally blackened”. Secondly, Kiaer (1898) wrote [translated from Latin]: “[..] variably orbits of eyes, tegulae, angles of pronotum [..] more or less testaceous”. Because of his use of the words “variably” and “more or less testaceous”, this description does not preclude the existence of syntype specimens with at least extensively black tegulae. Admittedly, the sempersolis lectotype has completely black tegulae, but because all other characters in Kiaer’s description fit, we find it unreasonable to reject its original status as a syntype merely because of this trivial discrepancy. Furthermore, it is possible that Kiaer mistook the large and pale humeral plates of the lectotype for the tegulae.
Host plants
Probably monophagous on Betula nana.
Genetics
COI
Based on 11 specimens, maximum within-species distance is 2.44% and the nearest neighbour, diverging by a minimum of 0.76%, is Euura hebes.
Nuclear
Based on 8 specimens, maximum within-species distance is 0.18% (0.15% based on haplotypes of individual females). The nearest neighbour, diverging by a minimum of 0.2%, is Euura lindqvisti.
Distribution and material examined
Palaearctic. Specimens studied are from Finland, Norway, Sweden, and the United Kingdom.
description: Published as part of 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), pp. 1-377 in European Journal of Taxonomy 977 on pages 147-149, DOI: 10.5852/ejt.2025.977.2799, http://zenodo.org/record/15019574