The female has the front and lateral mesonotal lobes often entirely red. The abdomen is mainly black above green beneath, the green turning to orange in death. The antennae are dark. The posterior of the scutellum, the postscutellum tergite and the first abdominal tergite are black.
Males are best determined by the shape of the penis valves and the presence of coriaceous patches on the scutelllum.
Euura sagmarius larvae feed on willows including grey willow.
Size: Female: 5.5 - 6.5mm, males: 4.5 - 5.5mm.
Distribution: England, Scotland, Ireland
Flight period: April to June
Plant associations: Salix spp. including Salix atrocinerea (willows including grey willow)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Liston A, Knight G, Sheppard D, Broad G, Livermore L (2014) Checklist of British and Irish Hymenoptera - Sawflies, ‘Symphyta’. Biodiversity Data Journal 2: e1168. https://doi.org/10.3897/BDJ.2.e1168
Prous, M., Liston, A., Kramp, K., Savina, H., Vårdal, H. and Taeger, A., 2019. The West Palaearctic genera of Nematinae (Hymenoptera, Tenthredinidae). ZooKeys, 875, p.63-127