Nematus latipes (formerly Craesus latipes)
One of four Nematus species in Britain and Ireland characterised by the enlarged basitarsal segment. This species is dulled in the centre of the upper part of the mesopleura by coarse, rugged microsculpture so that the punctures are scarcely discernible. Can be difficult to separate this species from Nematsus septentrionalis. In latipes the hind ocelli are as far apart as the distance from them to the hind margin of the head (1:1). In septentrionalis are closer together than the distance to the hind margin of the head (1:1.2).
Nematus latipes larvae feed gregariously on birch.
Size: 7.5 to 10mm
Status: Widely distributed
Distribution: England, Scotland, Wales, Ireland
Flight period: Bivoltine. May to June and July to September
Plant associations: Betula spp. (birches)
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