Tenthredo balteata - Lesser Ferruginous Sawfly

Recorded widely across much of Britain, perhaps more frequent further north; not recorded from south-west England to date (Musgrove, 2023).

A largely black and red species. The antennae are setiform, dark at the base and paler at the apex. The stigma of the fore wing is black, or nearly so. The head has clear punctures above and has a bronzy reflection in some lights. The thorax is largely black above and below and the abdomen is black at the base and apex with red tergites inbetween. Adults are often found in birch woodlands where the adults hunt for prey on trees.

Tenthredo balteata larvae feed on Bracken.

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Size: 9 - 10mm

GB IUCN Status: Least Concern
GB Rarity Status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: May to August

Plant associations: Polyphagous. Associated with birch woodlands and the larvae are often reported from Pteridium aquilinum (Bracken). Literature also cites Hypericum perforatum and tetrapterum (Perforate St John's-wort and Square-stemmed St John's-wort) as foodplants.


Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London

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]

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

Liston, A. D. 1982: Bracken as a foodplant for Tenthredo balteata Klug (Hym., Tenthredinidae). - The Entomologist's Monthly Magazine, Oxford 118(Sept.-Dec..): 198

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 Natural England, unpublished