The four species within the arcuata-schaefferi complex are problematic to distinguish and the species boundaries are unclear. The complex within Britain and Ireland consists of the species arcuata, brevicornis, notha and schaefferi.
Females of arcuata, in common with those of notha have have more rounded or blunt teeth that are shorter than the width of their base though there is evidence to suggest a continuum of variance between these and the more pronounced pointed teeth of brevicornis and the more rounded teeth of schaefferi. The hypopygium is deeply incised either side of the central point in common with brevicornis. The first tergite has the yellowing on the apical margin much reduced and often not reaching the lateral margin.
Males have the front femora largely marked with black on the inner face, this reduced to at most a thin line in the other species.
Tenthredo arcuata larvae feed on clovers, especially white clover.
Size: approx. 9 - 11mm
Distribution: England, Scotland, Wales, Ireland
Flight period: Uni- or bivoltine, April to June and sometimes July to August
Plant associations: Trifolium repens (white clover and possibly other clovers/trefoils)
The National Biodiversity Network records are shown on the map below. (See terms and conditions)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Lacourt, J., 2020. Hymenoptera of Europe 2. Sawflies of Europe. NAP Editions, Verrières-le-Buisson.
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]