What has happened to my apples?

Due to a much smaller fruiting (I think my tree is in a biennial fruiting at the moment - will have to confirm then correct next year) my apples are tending to be larger than last year.

However every single apple has been burrowed into.

Now I'm not very "hands on" when it comes to my fruit trees, and tend to just let them get on with it, but I would have liked a couple of apples!

I'm quite squeamish, and every apple must be peeled and sliced to test for invaders, and it rather spoils the enjoyment of eating direct from the tree

Yes.  Codling Moth.  Do you keep chickens?  I have heard that letting them run under the trees in winter helps clear up the hibernating pupae.

Gillie