What's happening here?

What's happening here?

Observation - What's happening here? - UK and Ireland. Description: Does anyone know what's happening here. These are beech leaves. Where there is a gall (Hartigiola?) on a leaf mine (Stigmella?)the leaf has retained its green colour. Does the insect cause this directly - is it the plant's response. Are senscence genes s

Does anyone know what's happening here. These are beech leaves. Where there is a gall (Hartigiola?) on a leaf mine (Stigmella?)the leaf has retained its green colour. Does the insect cause this directly - is it the plant's response. Are senscence genes switched off? Can the green part of the leaf still photosynthesise? Some of the Cynips galls of oak also retain their green colour when the leaf has died. So many questions!