Meadowsweet leaf damage for ID, please

Meadowsweet leaf damage for ID, please

Observation - Meadowsweet leaf damage for ID, please - UK and Ireland. Description: I'm in no doubt that this is Meadowsweet (Filipendula ulmaria) but what I'm interested in here are the red areas of damage. Fungal or insect? I don't know hence other organism for the moment. Can anyone suggest what has caused them, please?

I'm in no doubt that this is Meadowsweet (Filipendula ulmaria) but what I'm interested in here are the red areas of damage. Fungal or insect? I don't know hence "other organism" for the moment. Can anyone suggest what has caused them, please?