It is important, however, to find out the life cycle of the borer or insect causing the problem before treating the tree. It is useless to spray a tree with poison if the borer is happily nestled inside the tree where they are protected and getting fat eating your precious wood. Insecticidal sprays are normally targeted to keep borers out of trees, he adds. Knowing the life cycle provides the best timing for an application while the borer is exposed. Most insects spend part of their life outside the tree, then bore in as larva, or as adults after mating and laying their eggs.
Insecticides cover the vulnerable part of the tree with poison.
As the borer begins to eat its way back into the tree, it ingests the poison and we hope dies, before entering the tree. There are a few to consider planting in any landscape that are a little less expensive. Two small trees that are both attractive and have few problems are the crab apple and flowering crab apple. They range in size from six to 25 feet tall, depending on the variety, and are known for their graceful form, colorful leaves and distinctive shapes, Goodspeed says. They prefer a partially shady location with well-drained soil.