Cladius rufipes - Rufous Elm Knucklehorn

Cladius uncinnata Hartig, 1837
Cladius (Priophorus) rufipes Serville, 1823
Priophorus rufipes (Lepeletier, 1823)

North to southern Scotland. Apparently the less common of the two elm-feeding Cladius species, the assessment of which is clouded by unhelpful nomenclatural issues. Records assigned to 'ulmi' may have been subject to confusion, as Benson's Priophorus ulmi is not the same taxon as the currently recognised Cladius ulmi. Likely to have been affected by Dutch Elm Disease, but clearly able to persist on smaller hedgerow plants in the absence of larger trees (Musgrove, 2024).

According to Prous et al, 2019, there is currently no reliable key or species treatment available for this genus. The description follows Benson (Priophorus ulmi).

In the adult the head on the frons and temples above is smooth and shining without sculpture or hair-warts. Cladius rufipes is a black sawfly with yellowish tibiae and tarsi on all legs. The wings are more or less infuscated. The abdomen has a brown spot in the middle of the first tergite.

Larvae feed on elm.

Jump to other Cladius species

Size: 5 - 7.5mm

GB IUCN Status: Least Concern
GB Rarity Status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: Bivoltine, May to August

Plant associations: Ulmus spp. (elms)

The National Biodiversity Network records are shown on the map below. (See terms and conditions)

References:

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. 2024. A review of the status of sawflies of Great Britain - Phase 3: The Tenthredinidae (subfamily Nematinae). Natural England, unpublished

Prous, M., Liston, A., Kramp, K., Savina, H., Vårdal, H. and Taeger, A., 2019. The West Palaearctic genera of Nematinae (Hymenoptera, Tenthredinidae). ZooKeys, 875, p.63.