Thursday, November 1, 2012

*Update Possible Polyphagous Shot Hole Borer in the Wild on Coast Live Oaks

Just got back from a property located about 15 minutes northwest of here. The manager of the property found what looks like Polyphagous Shot Hole Borer on five Coast live oaks located in an historic stand in an unirrigated area. All five are dead or near dead, and the signs die back occurred within a months time. I am waiting on confirmation from Dr. Akif Eskelan and the folks at UCR, but it it isn't PSHB then its something that looks just like it. Below are images of the trees that were infested. If you see anything like this or what is described here, please contact me as soon as possible at 626 821-3236
Update: Akif Eskelan's lab has confirmed that this is NOT an infestation of PSHB (That's a relief). However it may be a previously unknown borer and fungus combination. 

-Frank McDonough, Botanical Information Consultant at the L.A. County Arboretum and Botanic Garden.

Possible Polyphagous Shot Hole Borer on Coast live oak (Quercus agrifolia)

Notice the dark, oozing stains that appear on the trunk. 

This almost dead Coast live oak has noticable soaking spots up and down its trunk. Most of these appear on the south side of the tree. 

Possible PSHB entry holes with oozing fluid.