Dolerus anticus
This species has the side lobes of the mesonotum black for at least the posterior two thirds. The scutellum, the first abdominal tergites and the legs are all black. Tergites lack sculpture except for tergite 1. 9-10.5mm.
Status: Very local
Distribution: England
Flight period: May to June
Plant associations: Eleocharis palustris (common spike-rush)
References:
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