Formerly in the genus Loderus as indicated by white or white tinged tergulae. The mesopleura are dull and rough with the middle covered in crater-like punctures that adjoin to give a honeycomb appearance. The body is normally black but the prothorax and abdomen may be more or less marked with red. Femurs and most of tibia red. Note that in some Scottish and Irish examples the legs are more or less entirely infuscate and the red may be restricted to only the front knees.
Distribution: England, Scotland, Wales, Ireland
Flight period: May to June
Plant associations: Equisitum sp. (horsetail - wet habitat species)
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