Trichiosoma sorbi - Rowan Hairy-clubhorn

Arguably the only Trichiosoma that is taxonomically well defined.  Mostly in the west and north of Britain and Ireland. In the female, the final 4 segments are adorned with closely adpressed silky white hairs giving a mouldy appearance. The male is difficult to separate from vitellinae but has a less rufous abdomen and with a less densely pubescent scutellum. The hind femur of the male has mostly dark hairs dorsally.

Trichiosoma sorbi larvae feed on Mountain Ash and other Rowan species.

Jump to other Cimbicidae

Size: 15 - 22mm

GB IUCN Status: Least Concern
GB Rarity Status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: May to July

Plant associations: Sorbus aucuparia (mountain ash).


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.

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 Natural England, unpublished

Viitasaari, M. 1989: Taxonomic notes on the genus Trichiosoma Leach (Hymenoptera, Cimbicidae) II. - Annales Entomologici Fennici, Helsinki 55 (3): 111-129