Urocerus californicus - California Horntail

Britain is not part of the natural range of this western Nearctic species. Just two records of this species in imported timber in 1944, and London in 1969 (Musgrove, 2022).

A variable species in its native Americas. Generally, the female has an abdomen almost entirely black. The wings are yellow with yellow venation. The male is banded on the abdomen with light reddish-brown on segments 3 to 10.

Urocerus californicus larvae feed in the timber of coniferous trees especially pines.

Jump to other Urocerus species

Size: 12 - 40mm

GB IUCN Status: Not Applicable
GB Rarity Status: Not Applicable

Distribution: Not recorded

Flight period: June to October

Plant associations: Pinaceae including Abies concolor (Colorado White-fir), Abies lasiocarpa (Subalpine Fir), Larix occidentalis (Western Larch), Picea engelmannii (Engelmann Spruce), Picea sitchensis (Sitka Spruce), Pinus contorta (Lodgepole Pine), Pinus ponderosa (Western Yellow-pine), Pseudotsuga menziesii (Douglas Fir), 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

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 Natural England, unpublished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.