Diastrophus rubi (wasp) gall on bramble

Diastrophus rubi  (wasp) gall on bramble

Observation - Diastrophus rubi (wasp) gall on bramble - UK and Ireland. Description: The ends of several low growing stems of a bramble Rubus fruticosus growing beside the River Bourne had these very deformed ends: Parasite/herbicide or other nk cause, any ideas???

The ends of several low growing stems of a bramble Rubus fruticosus growing beside the River Bourne had these very deformed ends: Parasite/herbicide or other nk cause, any ideas???