I have a Zabergau Reinette apple, which is grafted onto a Gravenstein. The Zabergau is getting destroyed by something while still being on the tree, whereas the Gravenstein is fine. I also have a Hudson's Golden Gem apple, also grafted onto another Gravenstein, which is having something similar happen, but yet the rest of the tree is fine, as is, the rest of my orchard, aside from the Zabergau. I have attached photos showing the damage. Thanks for any help.
Lane County Oregon apples
The fruit has been invaded by codling moth larvae. They tunnel to the seed area and feed and then, much larger, tunnel out through the flesh. The apple then begins to rot rather quickly. They are a big problem on the early apples, then a second generation of the moth attacks the later apples.