Question
i have recently planted 17 oak trees ranging from 60" box to 84" box two of the 84" boxed trees have been diagnosed with the gold spotted oak borer we will be cutting those down and getting rid of those trees my question is is there any preventative measures I can take to make sure that the other trees do not get this pest?

Answer
The researchers In Calif. have not come up with a prevention tool--researchers are real slow in trying anything practical especially insecticides in Calif. BUT a product called Bayer Advanced Tree and Shrub Insect Control will prevent another borer that is a first cousin of the spotted oak borer (emerald oak borer) I would recommend that you try the Bayer product. Check with your local garden type store for it. It is applied to the soil around the tree and the roots take it to the cambium layer and the twigs and leaves and if an insect feeds or borer into the tree it is killed. It will protect for the whole season. Here is a web link to this product. It should work for this borer.

http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-insect...