Food Plant: Epilobium montanum (Broad-leaved Wllowherb), E.palustre (Marsh Willowherb), E.lanceolatum (Spear-leaved Willowherb), E.hirsutum (Great Hairy Willowherb), E.tetragonum (Square-stalked Willowherb)

Mine: July-August

Notes: Makes a gall in the stem, generally near a leaf base. In Epilobium montanum (Broad-leaved Wllowherb) the galls are pea sized and may occur and occupy several leaf nodes. The stems are redder in this plant and much branched above the gall. In E.palustre (Marsh Willowherb) the galls cause a check on growth and shortening of the internode distance which leads to a mass of leaves and flowers at the plant apex, with side shoots much elongated as a result, raising them above the flower head. Pupation occurs in a white cocoon, with silk protruding out of the exit hole. The top photo shows the pupa in its silk chamber, with exit hole on E.tetragonum (Square-stalked Willowherb). Widespread but local in England and Wales. Found in damp woodland, open areas, shaded areas and waste ground.

Data: 14.vii.2020, Plympton, Devon, VC3 (top photo), pupa develops: 04.viii.2020, Plympton, Devon, VC3 (bottom photo).

Image:© Bob Heckford