Euura laeta (Brischke, 1883)

Liston, Andrew D., Heibo, Erik, Prous, Marko, Vårdal, Hege, Nyman, Tommi & Vikberg, Veli, 2017, North European gall-inducing Euura sawflies (Hymenoptera, Tenthredinidae, Nematinae), Zootaxa 4302 (1), pp. 1-115 : 61-62

Euura laeta (Brischke, 1883)

Cryptocampus laetus Brischke, 1883b: 204–205. Described: ♀, ♂, larva, gall, recorded host: Salix viminalis . Type material thought to have been destroyed, with most of the rest of Brischke's collection ( Blank & Taeger 1998) . Type locality: not mentioned, but presumably Danzig area , now in Poland. Authorship of the species name often wrongly attributed to Zaddach or Zaddach & Brischke.

Euura (Gemmura) viminalis Kopelke, 2001: 220 –221. Described: ♀, ♂, gall, recorded host: Salix viminalis . Holotype, ♀, SMF [examined]. Type locality: Czech Republic, Skalička near Hranice na Moravě. Synonymy by Liston et al. (2006). Notes. Prior to Liston et al. (2006) the name laetus or laeta was wrongly applied to the species now known as E. subgemma . Euura mucronata: Křístek (1972) , Urban (1995); misidentification.

Notes on types and taxonomy. C. laetus. The taxonomy and nomenclature of this species was last discussed by Liston et al. (2006), who concluded, based mainly on the biological data presented in the original description ( Brischke 1883b) and subsequently published figures ( Brischke 1884: plate I(8): figs 9a–9f), that the species name had been widely misapplied to a morphologically similar taxon on the same Salix host species. This second taxon was given the name subgemma . Although the original description of adult morphology of C. laetus is partly ambiguous, e.g. the body length given ("♀: L. 4,8— 4,1 mm. ♂ L. 5, 4, 3 — 4,1 mm ") is somewhat larger than in the laeta specimens that we examined, the biological data correspond unequivocally to that taxon, not subgemma . Accordingly, designation of a neotype for C. laetus is not necessary.

Apart from the different positions of the galls of E. laeta and E. subgemma, Urban (1992b) described and illustrated morphological characters that distinguish their larvae. Although he found that the size ranges of the larvae overlapped (possibly because the larvae were not sexed), the body lengths of adults which we examined are distributed in two discrete size classes according to species. These differences support the status of E. laeta and E. subgemma as separate species. Genetic data are available for E. subgemma but not E. laeta .

Variability. Female: Body length: 2.9–4.0mm. Clypeus entirely pale to almost completely black. Inner orbits narrowly pale-lined next to eye to completely black. Antennal flagellum nearly entirely pale, except basally, to nearly completely black. Male: 3.0– 3.7mm. Lower inner orbits pale to level of toruli; pale colour sometimes extending above this. Antennal flagellum entirely pale to basally infuscate on upper surface. Total number of specimens examined: 15.

Genetic data. No data available.

Similar species. Female; particularly similar in external morphology and colouration to E. subgemma , which also has S. viminalis as a host, but their lancets are substantially different, and the body lengths of each fall in two discrete ranges which do not overlap (see key). Male; not distinguishable from other nominal taxa in the mucronata subgroup.

Bionomics. Host plants: Salix viminalis ( Kopelke 2001) . Biology: Křístek (1972), Urban (1995).

Distribution. Central Europe and southern parts of North Europe, such as Denmark and Kaliningrad Region of Russia (Taeger et al. 2006). Occurrence in Sweden: not recorded, but possibly present.