One of the most common major threats to the health of an oak tree comes from oak tree borers. These pests are the larvae of beetles and moths and can cause considerable damage.
How Borers Attack
Female borers enter the tree through crevices on the bark. Once their eggs hatch, the larvae emerge to feed on the leaves and bark, drawing sap from the tree. Borers typically begin their attack at the top and move downwards, causing foliage to turn yellow-brown. As the damage increases, foliage will reduce, making the tree look thin and unhealthy, with branches gradually falling off.
Fighting Oak Tree Borers
Use an insecticide containing lindane on the trunks of any sick tree. Reapply the insecticide 2 weeks after the initial application and every month thereafter to contain reproduction.
Take care to protect your trees from getting injured as crevices and wounds will encourage tree pests to infiltrate the tree and hatch eggs. Also take care to prevent the tree from getting stressed from too much fertilizer or too much or too little water.
Inject orange oil or neem oil into the holes that contain the borers. These substances will help kill the insects.
Should your young saplings get infected, it is best to remove them altogether to prevent female borers from laying eggs in the wounds during later seasons.