Have a long think before going any further as it will certainly end up with Horse chestnut leaf miner - Cameraria ohridella, and will not be a pretty sight. Although you will be able to spray for a while, it will eventually get too big to deal with.

Thank you very much,sounds like I might leave it year and uproot later on, I must say it doesn't look all that good anyway! Thanks again.

Two years ago we had leaf miner on both horse chestnuts in the field I sent a sample to the research centre, they don,t think it will damage the trees as such, just not look very attractive, in fact last year the leaves and flowers were quite normal until late on in the season. The trees are not particularly old.....about 20 years and growing very big now