A cooler climate, northern species. Dolerus harwoodi is an all black species. The female with dense hairs on the head, mesonotum and mesopleura that are at least as long as the diameter of an ocellus. The male has sparse hair. Males best determined by the penis valve.
Larvae are unknown in Britain and Ireland but feed on pill sedge (Carex pilulifera) in Poland and other sedges are a possibility.
Flight period: April to June
Plant associations: Probably Carex spp. (probably sedges)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Borowski, J.; Slawski, M. 2018: Materials to the knowledge of Polish sawflies. The genus Dolerus Panzer, 1801 (Hymenoptera, Symphyta, Tenthredinidae, Selandriinae). Part XVI - Dolerus harwoodi Benson, 1947. - World Scientific News 111: 167-174.
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