What’s eating my tree?

Asked March 21, 2019, 4:28 PM EDT

I have a deciduous tree (oak? Maple?) that i recently discovered is being eaten away by some sort of bug. I am including a picture that shows the damage, as well as a bug that I’m assuming is responsible, but i am having trouble identifying. Some sort of bore beetle? I’m wondering 1. Can I get rid of the beetle? 2. Should I cut the tree down?

Clackamas County Oregon

3 Responses

The beetle in your photo does not look like the type of beetle that troubles trees. It is more likely a predator looking for other insects in the rotten wood. Further investigation is required to diagnose problems with your tree and help you decide what to do. That starts with "taking a history".
First, what species is the tree?
Is the tree crown or foliage showing signs of distress - dying leaves or branches, thinning canopy, late budbreak or early leaf fall?
What are the soil conditions - wet, dry, poorly drained, well drained, etc.
Have there been recent changes in conditions affecting the soil or the exposure?
I see what appears to be rotting wood, perhaps a scar where the tree was physically damaged?
etc.
It may be best to continue this inquiry directly via email.




Here are my best answers to the follow up questions. We have only been in this house for about 6 months and have limited knowledge about the tree.

First, what species is the tree? Green leaf maple. Possibly pictures will help further identify

Is the tree crown or foliage showing signs of distress - dying leaves or branches, thinning canopy, late budbreak or early leaf fall? Not that I have noticed.

What are the soil conditions - wet, dry, poorly drained, well drained, etc.
Have there been recent changes in conditions affecting the soil or the exposure? wet soil, poor drainage.

rotting wood/physical damage? Itdoes seem like the trunk is damaged. Possibly fire? Or just decay? Especially on the one side there is a large split that seems to be rotten deep inside (see pictures).
etc.


Your answers and the photos are very helpful. I can see that the tree suffered serious physical damage and has quite a bit of wood decay fungal activity along with insect activity in the exposed rotten wood. Carpenter ants are most likely since they usually colonize rotting wood. There will be a variety of other insects in the wood such as wood boring beetles. The big red beetle was probably a predator going after the larvae of other wood colonizing insects.

Clearly the tree trunk is seriously compromised and it will be prone to breakage under certain weather conditions such as strong wind, heavy snow, or ice. Your decision about whether or not to remove the tree will depend on how you feel about the hazards - what is at risk if the tree were to break and fall? On the other hand, if you like the tree, the fact that is has a healthy-looking crown (branches and foliage) indicates good prospects for the tree to keep growing new wood that may support it in spite of the damage. So you could just wait and see.

For a professional hazard tree evaluation you should look for a certified arborist. Otherwise, use your own judgement.