Benson (1952) treated Dolerus asper and brevicornis as a single species. They were split by Heidemaa et al. (2004), with the characters used to separate the two species being fairly subtle. It is likely that the majority of older records were named by reference to Benson (1952) and hence cannot be safely assigned to either species (Musgrove, 2023).
Males can readily be identified by the penis valve shape and the time of year. In females, the setae on dorsolateral edge of pronotum are as long as or longer than the diameter of an ocellus and the clypeus is more or less asymmetrical with the emargination approximately one half as deep as its median length. The hairs on the top of the head in both species are shorter than the diameter of an ocellus. See Heidemaa et al for key to separate the two.
Dolerus asper larvae feed on sedges and grasses.
GB IUCN Status: Data Deficient
GB Rarity Status: None
Distribution: England, Scotland, Wales (possibly Ireland)
Flight period: April to June
Plant associations: Cyperaceae (Carex, etc.) and Graminaceae (sedges and grasses)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Heidemaa, M.I.K.K., Nuorteva, M., Hantula, J. and Saarma, U., 2004. Dolerus asper Zaddach, 1859 and Dolerus brevicornis Zaddach, 1859 (Hymenoptera: Tenthredinidae), with notes on their phylogeny. European Journal of Entomology, 101(4), pp.637-650
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. 2023. A review of the status of sawflies of Great Britain - Phase 2: The Athaliidae and the Tenthredinidae (excluding Nematinae). Natural England, unpublished