Apple trees look like they have been caught by weedkiller

jonchap

see photo what is the cause is it insects,virus or chemical no aphids to be seen 

Pete.8

I does look like typical aphid damage.
If there are no aphids to be seen, maybe ladybird larvae have already visited and eaten them all.
That's exactly what I found on my blackcurrant bushes. Masses of aphids causing similar leaf damage, then the ladybirds finally arrived and have cleaned them up nicely and new leaves look good - but not many blackcurrants 

Chemical damage from over spray I guess is a possibility, but most of the older leaves look good.

jonchap

Thanks Pete.8  could be the reason no aphids around cheers