Autumn leaves

In the grounds of work I spotted this chestnut leave changing colours.

When I was in Switzerland most of the chestnut tree leaves had shrivelled and dried up. I think this is to do with a little weavel like creature that somehow manages to eat away all the nutrients left and the leaves just shrivel rather than age gracefully. It spreads very quickly so I think they can't really keep it under control. So far it seems that this tree has not got it yet.