The alder wood-wasp is one of three species in the genus in Britain. The abdomen is black dorsally without a red girdle and has lateral white spots. Antennal second segment is clearly shorter than the fourth segment. The hind basitarsus about the same length as the following three segments combined.
Larvae bore into the wood of ailing alders and birches in wetland habitats.
Size: 10 - 21mm
Distribution: England, Scotland, Wales
Flight period: May to August
Plant associations: Alnus spp., Betula spp. (alders and 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