Males exist in Europe but are more frequent in the south of the range. Mostly parthenogenic in Britain. A black and orange sawfly. Head and thorax black with orange on the tegulae metapleura and posteriorly on the mesopleuron. The abdomen is orange but with the first, second and apical tergites blackened to some extent. Legs orange with infuscated tarsi.
Halidamia affinis larvae feed on cleavers and hedge bedstraw.
Size: 5 - 6.5mm
Distribution: England, Scotland, Wales, Ireland
Flight period: April to June
Plant associations: Galium aparine and Galium mollugo (cleavers and hedge bedstraw)
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