Antennae with segment 8 twice as long as broad. Female mainly piceous black with a white labrum and tegulae and off-white knees, tibiae and tarsi of all legs. The male is mainly yellow with white on the tegulae and the outer edges of pronotum and otherwise mostly black or piceous. Frons with a distinct carina enclosing a supra-antennal field below and almost enclosing a frontal area above (open at the top).
Fenusella nana larvae feed in mines in the leaves of birches especially downy birch. Mines begin at a vein on the leaf edge and the entrance is plugged with frass. Larvae are green initially but turn more orange at maturity.
Size: Approx. 4 - 4.5mm
Distribution: England, Scotland, Wales, Ireland
Flight period: May to June
Plant associations: Betula spp. esp. Betula pubescens (birches esp. downy birch)
The National Biodiversity Network records are shown on the map below. (See terms and conditions)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
DeClerck, R. A. & Shorthouse, J. D. 1985: Tissue preference and damage by Fenusa pusilla and Messa nana (Hymenoptera: Tenthredinidae), leaf-mining sawflies on white birch (Betula papyrifera). - The Canadian Entomologist, Ottawa 117(3): 351- 362
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