oak tree - bark in poor condition

Question: Aside from the portion of the bark in bad condition (noted in the provided pics) this oak tree appears to be in good condition (and as you will see from one of the pics, it is appears to have healthy leaves). I do not see any insects infestitation (but that could be because I am not a trained eye). This has been the case for a number of years (at least for the last 5 years). Is this something I should be concerned about? And anything that I can do to help prevent damage? Thanks, Al

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied May 30, 2023, 1:28 PM EDT
response: Hello Al,  The foliage is difficult to see clearly but the tree appears to be a maple (likely Red Maple, botanical name Acer rubrum) and not an oak (Quercus). While that detail doesn't matter too much for every ailment, in some cases, the type of tree involved will help with making a diagnosis since vulnerabilities to certain conditions vary from one tree species to another.  We see what looks like borer holes in the exposed wood where the bark has gone missing. (We've attached an edited picture circling a few of them.) Borers tunneling into wood tend to target trees under stress (even if that stress hasn't yet manifested in an obvious way in the canopy), though not always. What caused the bark to fall off in that area in the first place is hard to determine; it could have been the activities of wood-boring insects or infection after a wound gave a pathogen an entry point.  The tree canopy does appear to be in good shape for now but we recommend you have the tree assessed by a certified arborist if you want them to look for more subtle signs of damage or other ailments. They also may be able to identify sources of tree stress that can be addressed to improve its ability to tolerate some damage. Some borers don't pose an urgent threat to tree health since they feed in its innermost wood (which is already naturally dead tissue) but enough boring damage could compromise its stability in storm winds. Borers are rarely treatable after an infestation has begun or been established after several years, since they are beyond the reach of most pesticides, plus a pesticide treatment would be a resolution of last resort since such chemicals risk harming other organisms. Not all tree-care company employees are arborists, though some arborists do work for them, but other arborists consult independently in case you're worried about a bias towards recommending expensive treatments.  Given the fairly small size of the emergence holes in the photo, Ambrosia Beetle is one possibility for the culprit, but we can't be certain. We don't see the classic tell-tale signs of "frass toothpicks" (sawdust-like debris pushed out of the tunnel by the beetles into a toothpick-sized plug) in the photos but they can easily weather away and be hard to detect unless fresh.  Miri

responder: The Question Asker Replied May 30, 2023, 2:02 PM EDT
response: Miri - Thanks for sharing all of the details. This is very helpful. I took your advice and connected with Richard Jones (he looks to be a certified arborist and connected to the UMCP program), Regards, Al  On Tuesday, May 30, 2023 at 01:28:30 PM EDT, Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied May 30, 2023, 4:45 PM EDT
response: You're welcome.