The horse chestnuts in the Church Yard of Old St Andrew's Church in Kingsbury were particularly lovely this Spring but have been hit again by what I believe is the larvae of C. ohridella leaf miner moth.
The current infestation (the pictures were taken this morning) is the worst I have seen since the first attacks several years ago, Eventually as can be seen the tree loses its leaves prematurely.
The trees will not be permanently damaged but the attacks seem to be happening earlier and with more intensity. It makes the trees unsightly in July and August when foliage should be at its healthiest.
One recommendation is that fallen leaves of affected trees should be collected up and removed from the site and burned. This is because the pupae overwinter in the 'mines' in the fallen leaves. I am not sure how practical that is on the St Andrew's site but sure possible for isolated trees in our parks.
Removal of the leaves mean that there will be fewer attacks over the season and they will be later, giving the trees more of a breathing space.
Treewatch, in association with the Royal Horticultural Society, are monitoring the disease and welcoem your reports: LINK
