A slender and mainly black insect with yellowish legs and infuscated wings. Antennae are similar to the Argidae but with a tiny additional segment at the tip. Adults are rarely encountered.
Larvae of Blasticotoma filiceti feed inside stems of fern fronds and their presence is indicated by a conspicuous walnut-sized froth ball on the frond stem.
Size: Approx. 8mm
Distribution: England, Wales, Ireland
Flight period: May? to July?
Plant associations: Athyrium filix-femina (lady fern), Dryopteris spp. (buckler and male ferns), Matteuccia struthiopteris (ostrich fern).
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
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