This species is very similar to Strongylogaster multifasciata. Strongylogaster xanthocera is the less common species.
Strongylogaster xanthocera males are more frequent than females, whereas males are rare in multifasciata. In the male the abdomen has the first tergite black right to the lateral margins and usually with at least the second tergite black also. Males of multifasciata have the first tergite marked with yellow on the lateral faces and the yellowing is greater on tergite 2.
Females of xanthocera have at least the first three antennal segments yellow, the epipygium is usually black and the hind femur is usually black almost to the apex. In multifasciata females, the third antennal segment is only partially yellow, the epipygium is usually brown and the hind femur is usually only black basally. The anal cells of the fore wing lack a cross-vein. The labrum is black. The sawsheath of the female is divergent at the apex.
Larvae feed on bracken.
Size: 8 - 11mm
Distribution: England, Scotland, Wales
Flight period: May to June
Plant associations: Pteridium aquilinum (bracken)
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
Macek, J., 2010. Taxonomy, distribution and biology of selected European Dinax, Strongylogaster and Taxonus species (Hymenoptera: Symphyta). Acta Entomologica Musei Natioalis Pragae, 50(1).