It seems likely that in Europe there may be several species aggregated under pallescens and there is overlap in the characteristics with Monophadnus monticola (not recorded from Britain). Males are rare. A small black sawfly with a brownish labrum and yellowish-white tibiae, tarsi and apices of the femora of all legs.
Monophadnus pallescens larvae feed on meadow and creeping buttercups and pupate under ground.
Size: 5 - 6mm
Distribution: England, Scotland, Wales, Ireland
Flight period: April to June
Plant associations: Ranunculus acris and Ranunculus repens (meadow and creeping buttercup)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Taeger, A. and Blank, S.M., 1998. Pflanzenwespen Deutschlands:(Hymenoptera, Symphyta): kommentierte Bestandsaufnahme. Goecke & Evers.
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