Hello, fellow Okie! It sounds like you should remove the ivy, but I could help you a lot more if you could get a picture. Mice and other vermin could hide in the ivy, and it could keep the trunk from drying out, thus encouraging fungal growth, but then again, it may not be harming anything. It may be that you have something going on that has nothing to do with the ivy. Can you give a detailed description?

Thanks for the pics. That is very severe damage, and I would definitely remove the ivy. This is certainly damage from the peach tree borer, which attacks cherries as well. Exposing the trunk will allow insect and bird predators a chance to eat the moths, their egss and the larva that then bore into the tree. It may even be that some of that damage was from someone getting carried away with a weedeater in the past, and that weakened the tree initially and made it more susceptible to borers, but either way, you have a serious problem. Gently clean away some of the looser bark and the gummy sap that's leaking out, and see if you can find obvious holes. If so, try poking a fine wire in to kill the borers, although they may not be there this late in the year. Lightly feed the trees after leaf fall with an organic fertilizer such as compost (if you have some), commercial mushroom compost or that sort of thing. Don't allow them to get stressed from drought. As for insecticide, I have yet to find the safest, best product...I would never use toxic poisons on fruit or food crops. I would go to the Organically Speaking section of this site, or look up peach borers on the web or at the state extension site. Good luck, Amigatec!