Eggs hatch in 15-20 days and the resulting larvae start to create tunnels under the bark feeding on the inner bark, cambium, and new wood. Healthy pecan trees fight flatheaded appletrees borers by producing excessive sap flow that can prove lethal to developing larvae. Trees weakened by stress often suffer the greatest damage from these borers, sometimes resulting in limb loss.
Although we find flatheaded appletree borers in most young pecan orchards, the damage caused by this insect is usually not serious enough to warrant a control program. The best defense against borers is the keep your trees healthy with adequate nutrients, water, and weed control.