Urocerus augur - Divining Horntail

Introduced into Britain and Ireland. The native range is in central and south-east Europe. The first definitive dated specimen seems to be from Kent in 1925, after which there were no more until one in Norfolk in 2020, and then three in 2021 (Sussex, Lincolnshire and Hertfordshire). None of the records have a documented link to imported timber, but instead have been found more generally. Now thought to be breeding in Britain after a female was observed ovipositing into Western Hemlock.

Very similar to the common Urocerus gigas, but the yellow behind the eyes is more extensive and the hind tibia black in at least the apical half. In the female the ovipositor is longer being about as long as the forewing.

Urocerus augur larvae feed in the timber of coniferous trees and take 2 to 3 years to mature.

Jump to other Urocerus species

Size: 12 - 40mm

GB IUCN Status: Not Applicable
GB Rarity Status: Nationally Rare

Distribution: England, Ireland, Channel Islands

Flight period: June to October

Plant associations: Pinaceae (coniferous trees) (1) including Abies alba (European Silver-fir), Abies cilicica (Cilician Fir), Abies procera (Noble Fir), Picea abies (Norway Spruce), Pinus sylvestris (Scots Pine), Tsuga heterophylla (Western Hemlock-spruce).


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

Liston, A. D. 1995: Compendium of European Sawflies. List of species, modern nomenclature, distribution, foodplants, identification literature. - Gottfrieding, Chalastos Forestry : 1-190

Musgrove, A.J. 2022. A review of the status of sawflies of Great Britain - Phase 1: families other than Tenthredinidae. Natural England, unpublished

Schiff, N.M., Goulet, H., Smith, D.R., Boudreault, C., Wilson, A.D. and Scheffler, B.E., 2012. Siricidae (Hymenoptera: Symphyta: Siricoidea) of the western hemisphere. Canadian Journal of Arthropod Identification 21: 1-305, 21, pp.1-305.