Arge pagana - Common Rose Fusehorn
One of the two yellow abdomened species that lack a black blotch under the stigma. Widely distributed in England and Wales north to the Tyne with no Scottish records at time of review (Musgrove, 2022). The pronotum, tegulae and parts of the legs are suffused with black. Wings more or less smoky.
The variation in the degree of dark markings gives two subspecies in Britain. The paler Arge pagana stephensii form has more extensive yellowing on the labrum, middle and hind coxae, femora and tibiae and sometimes upper mesopleural parts, pronotum and mesonotal lobes. Stephensii differs from all known populations of Arge pagana in the Western Palearctic. It cannot be discounted that stephensii may be a different species either endemic to the British Isles or introduced from outside of the Western Palearctic. The darker Arge pagana pagana form has head, thorax and legs entirely black. It is suspected that the two forms maybe separate species but further study is required.
Larvae feed on roses and can be difficult to distinguish from Arge ochropus. In pagana, the hairs on the head are usually pale, the supra-anal black mark is usually entire, and the lateral longitudinal rows of dots are aligned. The scar in the rose stem left by the ovipositing has a double row of cells in pagana and only a single row in ochropus Larvae feed gregariously on the young leaves first leaving only the midribs.
Size: 7 - 9mm.
IUCN Status: Least Concern
GB Rarity Status: None
Distribution: England, Wales
Flight period: May to September
Plant associations: Rosa spp. Roses (Benson, 1952)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Chevin, H., 1972. Notes sur les Hyménoptères Tenthredoïdes. Bulletin mensuel de la Société linnéenne de Lyon, 41(1) pp.2-5
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 Natural England, unpublished
Schedl, W. 1983: Zur Unterscheidung der Arten der Arge pagana (Panz.)- Gruppe. (Insecta: Hymenoptera, Argidae). - Gortania, Atti del Museo Friulano di Storia Naturale., Udine 4: 177-184.
Servadei, A. 1934: Contributo alla conoscenza dei Tenthredinidi (Hymenoptera Symphyta) delle Rose. II. Arge pagana Panz. - Bolletino del Laboratorio di Entomologia del R. Istituto Superiore Agrario di Bologna., Bologna 6: 179-208