I have decided to write this post because other people may be suffering similar problems. They may not know what it is or may just be too embarrassed to talk about it, so we need to bring it out into the open.
It was first observed in Wimbledon, London and since then it has been spreading outward at a rate of about 25 to 40 miles a year. There may still be parts of Wales, Cornwall and the North that remain unaffected but it is coming.
It is caused by the larvae of a moth and the key to identifying this particular pest is to hold the leaf up to the light, you should be able to see through the dark areas.
It is just an eyesore. A blight on an otherwise beautiful tree.
There is a much more serious threat to the Horse Chestnut called “Bleeding Canker” and that is what raised my concern in the first place but that is characterised by stains which look like bleeding on the trunk of the tree. That one can kill trees.