Females have reddish to yellow legs including the apical tarsal segments of all legs. The head and thorax are blue-black and the abdomen is dark brown. Basal antennal segments are often reddish brown with the remainder black.
Males are similar to the female but are banded in yellow on middle tergites and always with basal antennal segments reddish brown. Hind legs in the male are darker but with the apical tarsal segments still pale.
Sirex juvencus larvae feed in timber of conifers for up to 3 years.
Size: 10 - 40mm
Distribution: England, Scotland, Wales, Ireland
Flight period: June to October
Plant associations: Pinaceae spp. (firs, larches, spruces and pines)
The National Biodiversity Network records are shown on the map below. (See terms and conditions)
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
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.
Viitasaari, M. & Midtgaard, F. 1989: A contribution to the taxonomy of horntails with notes on the genus Sirex Linnaeus (Hymenoptera, Siricidae). - Annales Entomologici Fennici, Helsinki 55(3): 103-110