Insects and Spiders - invasive

Mediterranean Oak Borer (Xyleborus monographus) on Sep 20, 2023

Submitter does not have a specimen
EDRR Status: Population assessed

Description of specimen

The subject tree has two codominant stems measuring 21" and 28" DBH each. The 28" stem has reduced vigor and crown dieback. Very fine frass was observed on both the north and south faces of the lower trunk. No exit holes were observed, just frass. Exit holes of variable sizes are visible in a large wound where a leader failed about 10 years ago on the south side of the tree. I did not observe signs or symptoms of MOB in the other oaks in this small stand.

Commentary

As of 9/26/23: MOB confirmed (dieback, frass, external beetles) at site in one of the codominant trees. The other codom and other oaks onsite have no dieback, frass, or externally visible beetles.

Christine Buhl
Sept. 26, 2023, 10:54 a.m.