Moth flight begins around shuck split or shuck fall and continues for 6-8 weeks. Moths are active during the day, with mating and egg-laying occurring soon after emergence. Female moths are attracted to damaged and previously infested trees, and deposit eggs in cracks or under bark scales of wounded sites. Infestation is almost always associated with previously damaged trees. The problem tends to be more severe in older orchards that have a greater incidence of Cytospora canker, winter injury, and pruning and other mechanical wounds.
Older wounds appear dark due to the exudation of gum which oxidizes.
Larval feeding enlarges the wounded area which eventually results in complete girdling of the trunk or limb. The primary and earliest impact is a gradual decline in production on damaged limbs, which when girdled will break under a fruit load. With time, tree loss will occur from trunk girdling. LPTB feeding can also afford entry for disease organisms, eventually resulting in limb and tree death. Clear gum without wood borings or frass is not the result of borer injury.