Borers are young, immature insects that feed on the wood of fruit trees, and can cause significant damage to your crop if an infestation is found. Common borers found in fruit trees include flatheaded and roundeheaded apple tree borers, the peachtree borer and the shot hole borer. Treat your trees with a combination of vigilance and chemical control to rid your fruit trees of the pests.
Control flatheaded appletree borers by keeping your trees in good condition through fertilisation and wrapping, suggests the University of Missouri Extension. This type of borer usually extricates his adult self from your tree in May and lays eggs on the bark all summer. By fertilising areas of the trunk that are exposed, and wrapping the lower levels of trunk in burlap, the pests will not be able to lay eggs directly on the bark.
Cut the outer layer of bark on your fruit trees open if you notice larvae or adult borer worms, and kill the pests with your knife. This method works only if you only cut superficial layers of bark and see very few larvae on the bark; cutting too deeply will damage the tree.
Spray the lower limbs of your fruit trees liberally with chemical insecticides to kill off the bore worms and eggs -- enough so that the product puddles on the ground. Permethrin-based sprays can be effective in controlling appletree borers. Chlorpyrifos-based products are effective on peachtree borers and a simple wash of latex paint may control shot hole borers, according to the University of Missouri Extension.