One of the Tenthredo atra group (atra, ignobilis, moniliata). Tenthredo atra may eventually turn out to be a complex of further related species. The female differs from the other two species by lacking a red girdle on the abdomen. Males are red banded on tergites three to five and at least half the surface of two and six (much less than half in the other two species). The black antennae are setiform (ie. evenly thinning from base to tip). The mesopleura sometimes have a white mark. The hind femur is mostly reddish or yellowish. The stigma and costa are black (the same for ignobilis but brown in moniliata). The eye orbits in both sexes are black.
Larvae feed on a broad range of herbaceous plants. The similar looking Tenthredo moniliata is associated with bogbean, and Tenthredo ignobilis seems restricted to stonecrops .
Size: 9 - 12mm
Distribution: England, Scotland, Wales, Ireland
Flight period: May to August
Plant associations: Broad range of herbaceous plant incl. Lamium spp., Mentha spp., Plantago spp., Vicia spp., Ranunculus spp., etc. (dead-nettles, mints, plantains, vetches, buttercups, etc.)
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]
Liston, A.D., Knight, G., Heibo, E., Bland, K.P., Barstad, T.E., Blank, S.M., Boevé, J.L., Fiedler, C., Grearson, K.J., Halstead, A. and Jacobs, H.J., 2012. On Scottish sawflies, with results of the 14th International Sawfly Workshop, in the southern Highlands, 2010 (Hymenoptera, Symphyta). Beiträge zur Entomologie= Contributions to Entomology, 62(1), pp.1-68.