The best way I know of getting rid of those pines is to pull them out. I had a big patch of sumac that I ended up buying a 20' piece of 3/8" cable and used my 4x4 jeep in low to rip those suckers out of the ground, got most of the main
roots too. I've searched and have not found any animal that eats pine trees. The option of creating a small stand of Christmas trees is about the only other option I'm afraid.