Group piliserra

Description follows Liston et al, 2017. This group form willow leaf-rolls which curl down and inwards to form a tube which may contain several larvae. In Europe, there is only the single species Euura piliserra. In Britain, the hostplant is the widespread Common Osier and its hybrid cross with Goat Willow and Common Sallow. The piliserra species is bivoltine. The characteristics of the group are as follows. The mandibles are asymmetric with the right one being evenly tapered and the left narrowing rapidly from the base to a narrow blade-like apex. The cross vein 2r-m is usually present on the forewing submarginal cells. The supraclypeal region is densely haired and the antennae are long.  The penis valve of the males lacks any small spines ventrally. 

Group piliserra

Euura piliserra (Thomson, 1863) = Phyllocolpa piliserra (Thomson, 1863)

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

Liston, A.D., Heibo, E., Prous, M., Vårdal, H., Nyman, T. and Vikberg, V., 2017. North European gall-inducing Euura sawflies (Hymenoptera, Tenthredinidae, Nematinae). Zootaxa, 4302(1), pp.1-115.