Several of these on Horse Chestnut. I wasn't aware that the leaf miner had got that far up the country (the NBN maps don't appear to show it up there)
No interactions present.
Based on photos of the effects of Cameraria ohridella mines and of the Guignardia aesculi infection, you are correct that these are the larval mines. See e.g. http://www.nature-diary.co.uk/2005-09-24b.htm
This species has indeed reached this far north. There are three records from Northumberland from as far north as Morpeth and it was first recorded here in 2010. It is quite likely that organised searching would turn up more records.
Not noted in in County Durham in previous years when I'm up there (and have tended to check the Horse Chestnut trees I saw). The number of mines on the tree was far fewer than on trees down south.
The NBN map is pretty bad in terms of coverage: the usual problem - the map depends on record centres submitting data. A better representation of the distribution is here -
but this is doesn't show the Northumberland records. It won't be long now before the first for Scotland.
That's useful shows the distribution much better.
Not sure what the two dots out in the sea are about though.
I think the dots out in the Atlantic represent the Channel Islands, presumably moved to reduce the vertical size of the map.
If they are about you may find them in your car/transport, as they appear to be attracted to car interiors.
Here in Leicester the White Horse Chestnuts have been looking autumnal for 4-6weeks now, but with the wet weather the leaves are not as rolled-up as in previous years. This year the moths appeared to make a slow start.
Lat/Lng: 54.959285540279, -1.697301864624
OS grid ref: NZ194627