Is this a horsechestnut?

[cwmparc]

Hi,  I have two, what I thought were horse chestnuts trees, are they?  They both look sick especially the one on the right, is it okay?  There does not appear to be any conkers on them, may be a few.  I am sure they started off back in the spring with lots any idea why they would disappear?

[MattyF]

I’d be more concerned about the one on the left as it looks like die back in the crown unless it’s a dead ash tree behind ! 
The die back from chestnut is usually caused by bleeding canker and when it gets to the stage of visible dieback it’s usually because the branches have large areas of non functioning cambium that makes them prone to branch failure.

The tree on the right just has severe leaf minor which most chestnuts do … it usually starts to get very noticeable by the end of August.. best way of dealing with that is take all the leaves as soon as they drop and remove from site as the larvae will over winter in the ground once crawled from them .. it won’t stop it but trees I see that have this done look noticeably better.

[MattyF]

Looking at the picture again it does look like the die back is coming from the ash tree behind but the photo quality’s making it hard to see what actually is going on! 
 

[PeteB]

I find Chestnuts to start early and finish early. Round by us, they are already covered in brown leaves and finished now!

[Stubby]

48 minutes ago, PeteB said:

I find Chestnuts to start early and finish early. Round by us, they are already covered in brown leaves and finished now!

That is the leaf minor . They all have it around here . Does not kill them but makes it look like autumn in August .