One of four Craesus species in Britain and Ireland characterised by the enlarged basitarsal segment. This species is shining in the centre of the upper part of the mesopleura with the punctures clearly discernible amongst very fine microsculpture (Craesus alniasti lacks microsculpture here). The femora are mainly black. Males are unknown.
Larvae feed on hornbeam and hazel.
Size: 7 to 8mm
Flight period: May to June
Plant associations: Carpinus spp. and Corylus spp. (hornbeams and hazels)
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