Arge ochropus - Wild Rose Fusehorn
One of two yellow abdomened species that lack a black blotch under the stigma. Previously described as locally common south of the Severn/Wash line, there seems to have been a range expansion northward into Yorkshire and Lancashire (Musgrove, 2022). Arge ochropus can be separated from Arge pagana by the yellow pronotum and tegulae and yellow legs with black rings on the apices of the tibiae and tarsi. In Arge pagana these body parts are suffused with black. Athalia spp. are often misidentified as this species.
Larvae feed on roses and can be difficult to separate from Arge pagana larvae. The hairs on the head of the larvae of ochropus are often black, whereas in pagana the hairs are usually pale. The supra-anal black mark is often broken centrally in ochropus. In ochropus, the lateral rows of black dots running longitudinally are not in a straight line. Eggs are laid in a single row (visible in the twig scar), whereas eggs are laid in a double row in pagana.
Size: 7 - 10mm.
IUCN Status: Least Concern
GB Rarity Status: None
Distribution: England, Wales
Flight period: Uni- or bivoltine, June to August
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 Natural England, unpublished