A gall but which one, help please.

A gall but which one, help please.

Observation - A gall but which one, help please. - UK and Ireland. Description: Realising how difficult it is to ID without books or good internet connection? Think this one is a gall but no idea which one - any ideas? Not even sure of the host tree so have included a photograph, it looked like a fruit tree.

Realising how difficult it is to ID without books or good internet connection?
Think this one is a gall but no idea which one - any ideas?
Not even sure of the host tree so have included a photograph, it looked like a fruit tree.