Various kinds of borers can impact crabapples, not just the apple-bark borer, I know now after reading the fact sheets from various Cooperative Extensions around the country. Unlike the one in the photo up top, with borer entry points at eye level, one of my trees has damage at the base, more like what you’d expect from a vole, but there’s a tell-tale sign, Dennis explained: the presence of frass, or sawdust-like reddish debris that’s a combination of wood particles and insect wastes. Where you once would have seen cambium, you see frass. Sometimes cracks in the bark will also ooze sap.If you have a strong stomach and want to see what I am up against, Clemson University and Colorado State have some lovely photos of borers. I would have taken the shots myself had I been able to locate the hideous creatures, but so far no luck. If you are looking for me tomorrow, I will be out there with pieces of wire probing the tunnel system that was once my tree’s infrastructure, to