Blasticotoma filiceti Klug, 1834

Blasticotoma filiceti

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

Status: Rare

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).


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.