Abdomen red with dark apex. At least the front legs with some red about the knees. Mesopleura with crater-like punctures in the middle. Entire mesonotum black. Female 8-9mm. Male 7-8mm.
Dolerus cothurnatus larvae feed on water and marsh horsetail.
Status: Locally common
Distribution: England, Scotland, Wales, Ireland
Flight period: May to July
Plant associations: Equisitum fluviatile and palustre (water horsetail and marsh horsetail)
The National Biodiversity Network records are shown on the map below. (See terms and conditions)
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