Dolerus asper
This species has recently been split to separate our Dolerus brevicornis. Males can readily be identified by the penis valve shape and the time of year. 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.
Status: Widely distributed?
Distribution: England, Scotland, (possibly Wales and Ireland)
Flight period: April to June
Plant associations: Cyperaceae and Graminaceae (sedges and grasses)
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
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