A very dark species almost entirely black all over except for the more or less yellowish hind margin of the pronotum, tibiae and apical margins of tergites three to five. Wings infuscate especially at the apices.
Tenthredo neobesa larvae feed on sowthistles.
Size: 11 - 13mm
Status: Possibly extinct in Britain (last recorded in Wicken Fen)
Flight period: June to July
Plant associations: Sonchus arvensis (sowthistle)
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
Fekete, K. (2018) Beginner’s guide to identifying British Tenthredo, Natural History Museum, London. http://www.nhm.ac.uk/content/dam/nhmwww/take-part/identification-trainers/sawflies-guide-id-trainees.pdf [Accessed 26Apr2019]