Tenthredo omissa - Fen Sawfly

Benson (1952) only knew this species from East Anglian fen habitats, but a significant range expansion seems to have occurred and it has since been found across much of England and Wales, north to Cumbria and Yorkshire (Musgrove, 2023).

One of the smaller yellow and black species of Tenthredo. The flagellae of the antenna are entirely black as are the tegulae. The hind tarsus and apex of hind tibia is reddish-brown in both sexes. Yellow bands on the tergites do not broaden laterally. Formerly associated with the fens of Norfolk, Suffolk, Lincs and Cambs but now more widespread where similar habitats exist.

Adults of both sexes visit blooms especially white umbels such as cow parsley and yarrow. 

Tenthredo omissa larvae feed on plantains and possibly other herbaceous plants.

Jump to other species of Tenthredo

Size: 9 - 11mm

GB IUCN Status: Least Concern
GB Rarity Status: None

Distribution: England, Wales

Flight period: July to September

Plant associations: Plantago sp. (plantain)


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

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 Natural England, unpublished