Added to the British list in 2009, this species belongs to the Empria longicornis group. The posterior margins of the pronotum are pale. Paired pale patches on tergites 2 to 5 (or 6). The ratio of the antennal flagellae to the breadth of the head, along with genitalia characteristics are needed to confirm the identification of this group. See Prous, et al 2011.
Empria basalis larvae feed on water avens and possibly wood avens.
Size: approx. 5 - 7mm
Distribution: England, Scotland
Flight period: Assumed May to June
Plant associations: Geum rivale and poss. Geum urbanum (water avens and poss. wood avens)
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
Prous, Marko & Heidemaa, Mikk & Soon, Villu. (2011). Empria longicornis species group: Taxonomic revision with notes on phylogeny and ecology (Hymenoptera, Tenthredinidae). Zootaxa. 2756. 1-39. 10.11646/zootaxa.2756.1.1.