Cladius brullei - Brulle's Knucklehorn

Nematus brullei Dahlbom, 1835
Cladius tener Zaddach, 1859
Cladius tristis Zaddach, 1859
Priophorus foveivaginatus Malaise, 1931
Cladius immunis Stephens, 1835 
Nematus melanostigma Stephens, 1835
Priophorus morio (Lepeltier, 1823)

North to Orkney, seemingly common and widespread. (Musgrove, 2024)

According to Prous et al, 2019, there is currently no reliable key or species treatment available for this genus and this species is inseparable from Cladius compressicornis. The description follows Benson.

The head is dulled by fine surface sculpture or hair-warts. The wings are infuscate and the abdomen black usually with a brown spot in the middle of the first tergite. The median facial fovea between the antennae is separated from the frontal basin above by an unbroken ridge.

Larvae of Cladius brullei feed on brambles especially raspberry and also mountain ash. Also recently found on hawthorn. Early instars are pale green with a black head. Prior to moulting, larvae may temporarily cease feeding becoming off-white as the alimentary canal empties. The final instar has a reddish head with a broad dark patch on the vertex and a dark band between the eyes. The torso is pale beneath and dark olive greenish-black above.

Jump to other Cladius species

Size: 4.5 - 7mm

GB IUCN Status: Least Concern
GB Rarity Status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: Bivoltine, May to September (multivoltine in hot years)

Plant associations: Rubus spp., esp. Rubus idaeus, Sorbus aucuparia and Crataegus sp. (brambles, esp. raspberry, mountain ash and hawthorn)

Parasitoid associations: Campodorus difformis (Ichneumonidae)

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 Natural England, unpublished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.