Widespread but local throughout much of Britain (Musgrove, 2023).
The abdomen usually has tergites 2 to 5 banded reddish-yellow. The clypeus and labrum are black as are all the femora except at the extreme apex. The mesopleura are shiny and scarcely punctured.
Strongylogaster mixta larvae feed on lady fern and possibly other ferns. Late instar larvae are recognisable by the greenish grey ground colour on the upper surface, a mostly dark brown or black head and the presence of a black spot on the supra-anal lobe.
Size: 7 - 9mm
GB IUCN Status: Least Concern
GB Rarity Status: None
Distribution: England, Scotland, Wales, Ireland
Flight period: April to June
Plant associations: Athyrium filix-femina (lady fern)
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
Musgrove, A.J. 2023. A review of the status of sawflies of Great Britain - Phase 2: The Athaliidae and the Tenthredinidae (excluding Nematinae). Natural England, unpublished
Macek, J., 2010. Taxonomy, distribution and biology of selected European Dinax, Strongylogaster and Taxonus species (Hymenoptera: Symphyta). Acta Entomologica Musei Natioalis Pragae, 50(1).