Euura piliserra (Thomson, 1863)

Nematus piliserra Thomson, 1863: 616 –617. Described: ♀. Lectotype, ♀, designated by Kopelke (2007a), MZLU [examined]. Type locality: Sweden, Skåne, Arrie. Pontania piliserra: Konow (1890), as synonym of P. xanthogastra (Förster, 1854) [= Euura bipartita (Serville, 1823)].

Phyllocolpa piliserra: Benson (1960a) .

Nematus (Phyllocolpa) piliserra: Zhelochovtsev (1988) .

Pontania (Phyllocolpa) piliserra: Zinovjev (1993b) .

Euura piliserra: Beneš (2015b) .

Pontania piliserra var. mascula Enslin, 1915: 344 . Described: ♀. Lectotype, ♀, designated below. Type locality: Germany, Crefeld [Krefeld].

Pontania piliserra var. tristis Enslin, 1915: 344 . Described: ♂. Syntypes, ♂, should be in ZSM, but were not located. Type locality: not stated.

Pteronidea weiffenbachi Lindqvist, 1958: 107 –108. Described: ♀, larva, recorded host: Salix viminalis . Holotype, ♀, FMNH [examined]. Type locality: Germany, Niederhessen, Waldauer Bruch. Synonymy with Pontania piliserra by Vikberg (1970).

Notes on types and taxonomy. P. piliserra var. mascula . Lectotype, ♀, hereby designated, ZSM; labels: "Crefeld Rh. Ulbricht 5.", " Pontania piliserra v. mascula ♀ E. Dr. Enslin det.", "Sammlung Dr Enslin", "Type" [red], "GBIF- GISHym 3344", "Lectotype ♀ Pontania piliserra v. mascula Enslin, 1915 des. A. Liston 2016". No paralectotypes.

Variability. Female: Body length: 4.7–5.8mm. Black patch surrounding only ocelli or extending forwards to reach toruli and laterally on upper inner orbits nearly to eyes. Mesoscutum and mesoscutellum entirely black to extensively pale-marked. Mesepisternum entirely pale or with variably sized black patch on lower half. Male: 4.9– 5.6mm. Variability similar to female, but abdominal terga with black only medially on T1 to black medially on T1– 4(5). Total number of specimens examined: 8.

Genetic data. The CO1 barcode of the single specimen so far sequenced diverges by about 8% from its nearest neighbour ( E. anomaloptera).

Bionomics. Host plants: Salix viminalis (Kopelke 2007c), S. dasyclados (Vikberg 2010a) . Biology: Benander (1969), Beneš (1968a, 2015a), Brischke (1883a; as Nematus xanthogaster, misidentification). This is the only European gall-inducing sawfly, apart from E. amerinae, in which several larvae normally inhabit a single gall.

Distribution. Central and North Europe, to southern Scandinavia (Kopelke 2007c) and British Isles (Benson 1958). Occurrence in Sweden: published records; Skåne (Benander 1969, Coulianos & Holmåsen 1991). Material examined: Skåne.