I live in North Vancouver. Our Apple tree, about 6 years old, has developed a problem. I believe it is round headed Apple tree borer. Attached are some pictures. I have never spotted an adult but I can see the larvae. Wood bugs have also settled into the wounds now. This all appeared since spring of this year. We are thinking it is beyond repair and that we’ll need to take it out and put in a new one, however I’m wondering if the soil will be infected and it will be a problem for a new tree too. Advice?